MEDSCI206
ICM and Trophoblast cells are not totipotent. This means
ICM cannot form the placenta and Trophoblast cells cannot form the baby
Ionotropic
(Ligand Gated - our focus) They conduct current to activate the neuron (opening of ion channel for direct polarisation)
Metabotropic
(Neuromodulatory) They activate the neuron through *second messenger pathways* (act through a second messenger pathway for indirect polarisation)
What are (3) therapeutic strategies for immune cells in the brain?
(a) Phagocytosis for debris clearance (*Stop them from eating things*) (b) Inflammatory - cytokine/chemokine strategies (*secreting things*) (c) Suppression of APC activity (MS/stroke/autoimmunity) (*Presenting things*)
BDNF increases in response to (2)
*Exercise* and *environmental enrichment* (interacting with your environment) → ↑ BNDF → ↑neurogenesis and LTP → Improved learning and memory
What foraging structure of Astrocytes have?
*Filopodia* that sample the external environment
What is the neurotransmitter at the IHC afferent synapse? What does it bind to?
*Glutamate* from the *Ribbon Synapse*, binds *AMPA* (Glutamate Type 2/3) and *NMDA* (NR1) receptors https://o.quizlet.com/h.AXdsTJiF1UX4b-X2ovbg_m.jpg
[Figure] Surface preparation of the rat organ of Corti
*I*HC *P*illar Cells *O*HC *D*eiters' Cells https://o.quizlet.com/1yaloeChe3NQA9y.nBHDLw_m.jpg
Which membrane proteins strengthen the adhesion between the leukocytes and the endothelial cells? (2)
*ICAM-1 (CD106)* and *VCAM-1 (CD54)* (Two of the most important endothelial-leukocyte adhesion molecules that govern trafficking of peripheral immune cells into the inflamed CNS)
Symptoms (3)
*Involuntary Movements* Emotional Problems Both
Which common features do senses share? Pathway
*Physical stimulus* (Neural code in the nerve that will give precise info about the type, duration and intensity) Events transform stimulus -> nerve impulses Response of signal gives rise to *perception* or *experience of sensation*
The basal ganglia have outputs to which (3) structures, via which relay station?
*Prefrontal Cortex*, Premotor Cortex and Primary Motor Cortex via the thalamus
The hair cells are innervated by (neurons and nerve)
*Primary Auditory Neurons* -> Spiral Ganglion -> Cochlear Branch of the Vestibulocochlear Nerve (8th)
The sensory cells in the Organ of Corti are innervated by the (which cells) (from which structure)
*Primary Auditory Neurons* located in the Spiral Ganglion (both afferent and efferent innervation)
Stage 3: This process of shortening of the OHCs and cochlear amplification is called (2)
*Reverse transduction* or *Electromotility* (amplifies the movement of the organ of corti - the organ of corti moves up and down more vigorously)
Types of Motor Units
*S Type/Type I* (Slow twitch) *FF Type/Type II B* (Fast twitch, fast fatigue) *FR/Type II A* (Fast twitch, fatigue resistant) - rare
Example patient of why forgetting is important?
*S* could not erase information, didn't know what was important in life (could not filter incoming information)
Hippocampal Lesions affects
*Spatial* Memory Consolidation https://o.quizlet.com/u9XoD2KCiHvQwggGVGxvlQ_m.jpg
Dorsal "Where" Pathway/Stream
*Spatial* Processing - Location, movement, spatial transformations and spatial relations
The best sensitivity of the cochlea is between
1 - 2 kHz https://o.quizlet.com/5WwY-5iIIeMXFlaVhtELdw_m.jpg
Which (3) zones is our visual field made up of?
1 Binocular Zone 2 Monocular Zones
Top three causes of death
1 CVD 2 Cancer 3 Stroke
Primary Somatosensory Cortex (S1) Brodmann Areas? (4)
1, 2, 3a, 3b,
Which cranial nerves only sensory?
1, 2, 8
How does atherosclerosis cause ischemic stroke? (4)
1. Endothelium ulceration overlying plaque → Platelet/Fibrin adhesion. Platelet-fibrin thrombus break loose into circulation → block small artery in brain (thromboembolism) 2. Endothelium platelet adhesion → coagulation cascade → formation of occlusive thrombus (can block distal arterial branches) 3. ↓ flow / inadequate perfusion of brain distal to narrowed / occluded artery → infarction (necrosis). 4. Haemorrhage into a plaque → rapid reduction in the diameter of the arterial lumen
Biochemical changes in brain during ischemia which potentiate cell death (7 steps)
1. K+ moves into the extracellular space of the brain 2. Ca++ moves into cells 3. Mitochondrial function compromised 4. Na+, Cl- ions and water enter neurons causing cell swelling 5. Release of oxygen free radicals → peroxidation of fatty acids in cell organelles and membranes 6. Anaerobic glycolysis → accumulation of lactic acid 7. ↑ activity of excitatory neurotransmitters
Ischemic stroke: clinical syndromes (4)
1. Total anterior circulation infarct (TACI) 2. Partial anterior circulation infarct (PACI) 3. Posterior circulation infarct (POCI) 4. Lacunar infarct (LACI)
Which cranial nerves sensory and motor?
3, 4, 5, 6, 7, 9, 10, 11, 12
How many types of T2R receptors are there?
30 different types
Most voices are about
300 Hz https://o.quizlet.com/4Mosv-64.3pyrif28rIiLQ_m.jpg
Spinal cord segments?
31
Infants at which preterm age have most problems?
32 weeks
How many Spiral Ganglion Neurons and what do they innervate?
35-50k, innervate mainly the IHCs
What is the ratio of Hair Cells?
3:1 (OHC:IHC)
The Visual/Auditory/Olfactory systems gives us information about the
3D Environment (some distance)
Negatives of this initial treatment?
4 developed cancer (leukemia) and 1 died
Innervation ratio range?
5 - 2000
How many waves are recorded with BAEPs in humans and other mammalian species?
5 https://o.quizlet.com/.w5bXbblJ9ZJfbto6eOJRw_m.jpg
How common?
5-10/100,000
What happens in AD with respect to the Cholinergic System ?
AD → Degeneration of Cholinergic Neurons ACh (Acetyl Choline) which project to Hippocampus and Neocortex
Presynaptic Terminal is made up of (2)
Active Zone and Synaptic Vesicles
Pathological Forgetting is termed
Amnesia
Prevent thrombus/embolism
Anti-platelet drugs (aspirin).
Genetics of HD? (4)
Autosomal dominant Chromosome 4 (Short arm) Gene IT15 Polyglutamine Regions - CAG repeats within Huntingtin (Htt) protein
Myotatic Reflex Efferents
Axons of αMNs
Astrocytes are a very important component of the
BBB
Being lipophilic, cannabinoids
Bind the receptors within the transmembrane domains
Asphyxia
Body deprived of oxygen
E-Selectin and P-Selectin are
CAMs found on endothelial cells
What is the Astrocyte progenitor function?
Can potentially differentiate into other cells
Which genes are turned on for formation of the striatum? (2)
DARP32 an Meis2
When do we have synaptic elimination or pruning?
During sleep - needed so that we can learn more
Short term memory is known to be
Dynamic
Perilymph
ECF, high Na and low K
Microseizures?
EEG spiking events observed after latent phase https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
Scala media fluid is
Endolymph - High K, Low Na, resembles intracellular fluid
Another name for the Ear Canal?
External Auditory Meatus
What type of receptors (physiological) are nocioreceptors?
Free Nerve Endings
Growth factors are released in _____, which helps to
Gradients, which helps to shape the growth of the nervous system
Stage Theory: What is the *second* group of neurons in the neural stage?
Green and Red processing, input from GR
Declarative: Short Term located
Hippocampus
Impaired oxygen delivery and Impaired waste removal lead to
Hypoxia + acidosis
What are we not considering with the Flexion (withdrawal) Reflex?
If muscles are flexed synchronously, you can lose balance
What *type* (there are 2) of immune function do Microglial Cells manifest?
Innate Immunity
Peripheral Nerve Somatosensory Injury symptoms?
Loss of sensation of areas innervated by that nerve Tingling, numbness or pain
Dementia
Loss thinking, remembering, and reasoning
Cholinergic system is important in?
Memory, sleep and arousal
What are the leukocytes that stick? (3)
Monocytes, B and T Lymphocytes
If mitochondrial PO2 = <1mmHg, what happens?
No more ATP produced (OP)
2. Partial anterior circulation infarct (PACI)
Occlusion of internal carotid artery, anterior/middle cerebral artery. Clinical features: (1) TACI problems (2) Cerebral problems (3) Unilateral motor/sensory deficit
What are the (4) pluripotency inducing genes?
Oct4 / Sox2 / Klf4 / c-myc
Hippocampus is highly
Organsied
Which *genes* are turned on for formation of the Cortex? (3)
Pax6, Emx2, Dlx2.
Metencephalon
Pons
What makes up the 𝛾 secretase?
Presenilin 1, 2
Soleus has mainly what fibers?
S Type
Sensory 1 - Overview
Sensory 1 - Overview
LTP?
Simultaneous stimulation of 2 neurons → Long-lasting improvement in communication Strengthening of synapses
Sources: Propriospinal Neurons
Spinal neurons w/ascending/descending neurons for upper/lower limb co-ordination
OHCs sit on
Supporting Deiters' Cells
What causes the high [K] in the endolymph?
The secretory activity of the Stria Vascularis
How many types of sensory cells are there in the taste bud?
Three: Type 1, Type 2 and Type 3 https://o.quizlet.com/TNwfpdFbbQ6fPw7fhk1Vqg_m.png
What is the basic principle of frequency encoding in the cochlea?
Tonotopic Organisation
Somatic Gene Therapy
Will modify patient DNA and not passed down to offspring
Hypoxia
↓oxygen reaching tissues
Use it or lose it?
↓rate of cognitive decline by using memory
What is an example of a common cannabinoid?
∆9THC (Marijuana)
Intrafusal Fibre Non-belly sections are innervated by
𝛾 Motor Neurons
PSA-NCAM benefits?
(1) *Large tightly bound molecule*, does *not interact* with other things (therefore cell cannot interact with surroundings) (2) *Hydrous*, binds a lot of water. This helps the cells to slide and squeeze through in adult aged brain (through all the myelin). Wouldn't need this when baby did not have myelin.
Stage Theory: What is the overall mechanism?
(1) Activation of L, M and S cone pigments (2) Opponency pathways that allow us to sort colour information for black/white, yellow/blue and red/green (3) Brain combines the information received from the retina to give rise to perceptions of different wavelengths of light
How can Gene Therapy be used in Neurological Diseases? Remove/insert/modify genes that will... (3)
(1) Block genetic mutation expression (2) ↑Neurotransmitter/Neurotrophic Factor (Neuroprotective Agent) production (3) ↑Enzyme production/function
What are the motor unit components? (5)
(1) Cell Body of α Motor Neuron (2) Axon (3) Axon Branches (4) Neuromuscular Junctions/Endplates (5) Extrafusal Muscle Fibres that the Motor Neurons innervate
(3) Phases of brain Injury
(1) Insult Phase (2) Recovery Phase (3) Reorganisation Phase https://o.quizlet.com/XSaMdbjXN9o4Gu.1UssCrQ_m.png
(4) Homeostatic mechanisms?
(1) Ionic Gradients (2) ATP production (3) Oxygen/nutrient perfusion to brain (4) Match cellular metabolic activity (demand) to energy supply
What are the two modes of Radial Migration?
(1) Locomotion (2) Nuclear Translocation/Nucleokinesis
Processing of sound: Subtle Nuances underpin (2)
(1) Social communication (2) Sound localisation
How are disease models used? (3)
(1) Understand Disease Pathogenesis (2) Identify molecular targets to slow/stop disease progression (3) Testing of new drugs (proof of concept)
The presence of which of the following features excludes diagnosis of lacunar infarct?
(1) Visual field defect. (2) Abnormal higher cerebral function (eg, dysphasia, apraxia). (3) Signs of a brain stem abnormality (eg, gaze palsies, crossed deficits). (4) Impaired level of consciousness (drowsiness, stupor or coma).
Reciprocal Inhibition in the Myotatic Reflex - what are the pathways from the Ia Afferent?
(1) → (Glutamate) → αMN1 → Biceps Contract (2) → (Glutamate) → Ia inhibitory interneuron → (*Glycine*) → αMN2 → Triceps Relax
What are the (2) types of postsynaptic transmitter receptors at CNS synapses?
(A) Transmitter/Ligand Gated Ion Channels - Rapid (B) G-Protein Coupled Receptors - modulatory
What is the relation between characteristic frequency and the respective position on the basilar membrane? (The rule of thirds)
(Approx logarithmic) 20-200Hz take apical 1/3 of BM 200-2,000Hz take middle 1/3 of BM 2,000-20,000Hz take basal 1/3 of BM https://o.quizlet.com/Nt48XRUK6KMaho5LFbGkOw_m.jpg
Vonsattel Grading Scale
*0* = Minimal change → 40% loss of MSNs *1* = 50% loss in CN, shrinkage visible to the eye Have to look at the cells also, ratios etc. *2-3* = Major loss of neurons (~70%) CN pretty much flat *4* = 95% loss of neurons in the CN Concave CN
What are the efferent OHC neurotransmitters?
*ACh* (acts on nicotinic Type 9 receptors) and modulators CGRP, ATP and GABA https://o.quizlet.com/D.kJdh.rdNA-mRh1f7A.3Q_m.jpg
What are the efferent IHC neurotransmitters?
*ACh, GABA and Dopamine* (Also modulators Enkephalins, Dynorphins and CGRP - Ca Gene Related Peptide)
BDNF (4) features
*Activity dependent* release *Receptors coexpressed* with glutamate receptors *Made, stored and released* by glutamatergic neurons High *hippocampus expression*
How do Chordin and Noggin work?
*Bind BMP* and prevent them binding their receptors
The neurons from the *Ventral* Cochlear Nucleus lead to?
*Both* Superior Olivary Complexes
Diagnosis of Parkinson's Disease (4)
*Clinical* diagnosis (2 or more cardinal features) *Laboratory* Tests Response to *levodopa* No *alternative cause* for symptoms
Multisynaptic pathways to the cerebral cortex provide
*Complex analysis of incoming information* https://o.quizlet.com/OJz8EXwX9jX5LmbCr7gmsA_m.png
Sensation and Perception: Smell and taste
*Detect* chemicals (aromatic compounds) in air or water but *experience* smells and tastes https://o.quizlet.com/S8lIvgquYEU1uQUcQEA2PA_m.png
Sensation and Perception: Light
*Detect* light of different wavelengths and *perceive* as colour https://o.quizlet.com/VAIhhCApDKb.hnroyhyxAA_m.png
Sensation and Perception: Sound
*Detect* vibrations of different amplitudes and frequencies but *hear* sounds, speech https://o.quizlet.com/sO.A7BS5wbirl2FCP84c3g_m.png
Odors can arouse _____ and affect _____
*Emotions* and affect *behaviour*
Differential Diagnosis (8)
*Essential* tremor - not the rest tremor we expect to see in PD Temporary improvement with *alcohol* Family *history* Drug Induced (the ones they are taking for other problems) Cerebral infarcts/strokes near basal ganglia Hydrocephalus (fluid in brain) Other Neurodegenerative Diseases (PSP MSA) Wilson's Disease (copper accumulation)
How does asphyxial insult affect Brain Oxidative Metabolism (graph)?
*Insult* = Acute loss of OM *Reperfusion/Latent Phase* = Recovery of OM *Secondary Phase* = OM Failure - gradual decrease (8 hours after) https://o.quizlet.com/L12pT5aVQIGEfjiTwwaZvQ_m.png
Tangential Migration
*Leading processes* forage for target through *somal translocation*
Endoderm forms (4)
*Lining* of internal organs, GI tract, respiratory and *endocrine*
What are the (4) classes of receptor (in humans - think of senses)?
*Mechanoreceptors*: detect mechanical deformation *Chemoreceptors*: detect chemicals, nose, taste or CO2 in blood *Thermoreceptors*: detect changes in temperature, thermoregulation *Photoreceptors*: detect light https://o.quizlet.com/hsE5Sj4nWMjcbZCy0NhpIQ_m.png
What is the negative effects of pregnant mothers smoking?
*Movement/positioning* of neurons is altered (we know that position determines function), in week 6-12 mark when the neural development is critical
Since the initial pioneering studies in 2004- 2007 cannabinoid CB2 drugs have shown improvements rodent models of which diseases? (3)
*Multiple sclerosis* *Viral encephalopathy* *Huntington's disease*
Phantom Limb: Normally?
*Neuronal inhibition* keeps functional areas distinct (i.e. finger 2 region separate from finger 3 region) https://o.quizlet.com/nyLq9LpUvPNCFaiO5Z5dZQ_m.jpg
CAG (Glutamine) repeats ranges (3)
*Normal* = Up to 35 repeats (short expansion) *Gene Carrier* = 35 - 40 (Symptomatic) *HD* = 40+ (Long expansion)
What is the pathophysiology in Lissencephaly?
*Not hopping off* radial fibre or *Poor Migration* -> abnormal accumulation of cells
In the normal brain, CB2 receptor is
*Not* highly expressed
Which mammalian gene family is the largest?
*Odorant receptor genes (ORgenes)* (900 genes in humans, 1500 in mouse)
On Type 2 cells (bitter, sweet and umami), the release of ATP activates
*P2 Receptors* on the nerves (P2X2, P2X3) and binds back on to the Type II cells, possibly to enhance the signal https://o.quizlet.com/JV5WC22.GSu53BpyOgDxVQ_m.jpg
What olfactory molecules are used by insects? How is olfaction of these molecules involved in communication? (4)
*Pheromones*. Signalling reproductive behaviours Marking territory Signalling aggression, fear
CB2 is substantially increased in which diseases? (6)
*Stroke* (No human data yet) - only been studied in mice) *Multiple Sclerosis* (human) *Huntington's Disease* (human) *Down's syndrome* (human) *Alzheimer's disease* (human) *ALS* (mouse SOD-1 model) - Motor Neuron Disease
What happens at the age of 2 that helps reduce neuron numbers?
*Synaptic Elimination* and *Cellular Pruning*, reducing neuron number from 320 billion to 160 billion (we live with the latter throughout our life)
What are some auditory (localise sound) adaptations of animals?
*Tachinid fly Ormia ochracea*, specialised hearing organ - a *beam* that bounces and tells the fly where spatially the sound is coming from https://o.quizlet.com/EWUF707MI.g7-0m1bMX0wQ_m.png
What is a non-invasive technique that can be used to stimulate the nervous system?
*Transcranial magnetic stimulation* (TMS): Place a plastic coated coil connected to a capacitor that discharges, producing a very brief/small magnetic field. Place this near the Primary Motor Cortex and depolarise the neurons -> causes muscle contraction.
Perirhinal Cortex Lesions affects
*Visual* Perception and Memory https://o.quizlet.com/UpqNJAem6pskOM3QkIo5TQ_m.jpg
Differences between brain vasculature and other vasculature? (2)
*•* Brain vasculature is associated with astrocytes *•* Level of expression of tight junctions in the BBB is higher than anywhere else in the body
Maternal Inheritance of CAG repeats
-4 → +4 (on average 0) change from maternal repeat number
Human olfactory bulb is (%) of the brain
0.006%?
What is the Interaural Time Delay if the sound is coming directly from *one side*?
0.8ms
What is the Interaural Time Delay if the sound is coming directly from the *front*?
0ms
What is the Interaural Time Delay if the sound is coming any where between *0˚ (directly ahead) and directly from one side (90˚)*?
0ms < x < 0.8ms
Long-term Memory
1 second - lifetime
ISCHAEMIC STROKE Symptoms (3)
1. Anterior circulation 2. Posterior circulation 3. Lacunar infarcts
ISCHAEMIC STROKE Causes (3)
1. Arterial disease. 2. Embolism. 3. Reduced systemic perfusion pressure.
How many axons of ganglion cells transmit information from the retina to the brain?
1.2 million (~100x less than photoreceptors)
Maintaining Membrane potential requires
1/3 of all ATP produced
When do we have the max number of hair cells?
10 weeks gestation - after this we can only lose the cells
LTP: Late Phase
10+ hours, now affecting transcription and protein turnover (∆structure of neurons and networks)
How many cells does 1 mother cell produce?
10,000
What is the range of capillary sizes in the brain?
10-20µm -> 100-150µm
Stage 2: How many stereocilia on an OHC?
100
Papillae have how many of what?
100-900 taste buds, visible only with a microscope
Each neuron has how many connections (synapses) with other cells?
1000 or more
P Cells outnumber the M Cells by ____x in the
100x, in the retina
How does the olfactory epithelium surface area compare between humans and dogs?
10cm^2 humans vs 170cm^2 dogs
# of cranial nerves?
12
How many OHC in human?
12,000
The frequencies used in Pure Tone Audiograms are (range)
125Hz - 8kHz
How many photoreceptors absorbing light?
126 million
Average duration from diagnosis to death is?
13 years
When is ultimate prognosis?
15 years terminal
Intracerebral haemorrhage (ICH)
15% Bleeding into brain (small artery supplying deep white matter and basal ganglia) Haematoma → cuts off brain pathways → exerts pressure on surrounding brain tissue
Myelination continues untill
18-20 years of age
What is the neuron:Glial Cell ratio?
1:10
The ratio of cones:rods?
1:20
Microscopic Pathology of HD? (Specific)
1st: Loss of GABAergic Neurons called Medium Spiny Neurons
Anterior Spinocerebellar Tract Pathway
1˚ = Dorsal Root → Synapse at Dorsal Horn 2˚ = *Spinal Border Cells* → Decussate → Superior Cerebellar Peduncle → Cerebellum
Posterior Spinocerebellar Tract Pathway
1˚ = Dorsal Root → Synapse at Dorsal Horn 2˚= Afferents → *Clark's Nucleus* → Inferior Cerebellar Peduncle → Cerebellum
Dorsal Column/Medial Lemniscus Tract - Pathway
1˚ = Skin → Dorsal Root → Fasciculus Gracilis/Cuneatus (T6 separates these) 2˚ = Nuclei Gracilis/Cuneatus → Decussate → Medial Lemniscus → Thalamus 3˚ = Thalamus → Primary Sensory Cortex https://o.quizlet.com/mXJOZPcG-E5zCxDM4Cow.A_m.png
Anterior/Lateral Spinothalamic Tract - Pathway
1˚ = Skin → Dorsal Root → Synapse in Dorsal Horn 2˚ = Decussation → Anterior/Lateral Spinothalamic Tract → Thalamus 3˚ = Thalamus → Primary Sensory Cortex https://o.quizlet.com/0SfVPdmc5AOShsy4G0yuzA_m.jpg
You reach a maximum synapse number at which age?
2 Years
LTP: Early Phase
2 hours, protein modification
CaMKII constitutes how much of the total protein in the neuron?
2% - high proportion
Mortality compared to age-matched controls? (How may times)
2-5 times
The human ear recognises frequencies between
20 - 20,000 Hz as sounds
Our olfactory system can detect how many different substances?
200,000
How near are blood vessels when looking at individual neurons?
200-300µm
Medicine allows us to keep alive how old babies?
23 weeks (severe problems in life)
Temporary Hearing Loss can recover within
24 hours - 7 days
% of strokes occur in people under the age of 65?
25%
What is the latency in the Myotatic Reflex?
25-30ms
What are (2) major Endocannabinoid ligands?
2AG and AEA (Anandamide)
Optic Nerve
2nd pair of cranial nerves - retina to brain https://o.quizlet.com/i/J6NmyM7jL8NsuH-oDazNCg_m.jpg
Opponent Colour Theory: Channels respond in which way?
3 channels: Red/Green (are processed by the same group of neurons), Blue/Yellow and Black/White, with each responding in an antagonist (opposite) way
% of people over 65 with Parkinson's?
3%
How many IHC in human?
4,000
Some axons extend distances that are
40,000 times width of the cell body it is attached to
How high can dogs and bats hear?
40kHz (Dogs) and 160kHz (Bats)
Onset?
40s
Which Broadmann's area refers to the Auditory Cortex?
41
The basilar membrane recognises which frequencies at which locations?
45kHZ (high) at the base - 200Hz (low) at the apex https://o.quizlet.com/JwkgKc9zUh0E8zVU6Pd12w_m.jpg
What (%) of neurons are replaced a year (olfactory)?
5%
Normal cerebral blood flow is
50 ml/100g/min
How many neurons created in the first 7 months of life die? (%)
50%
There is a ____-_____ms delay for the initiation of the Attenuation Reflex, which means
50-100ms, not perfect at protecting your ear from a sudden burst of sound (i.e. explosion)
How many taste receptors per taste bud?
50-150
How many layers of neurons are formed?
6
LTP: Intermediate Phase
6 hours, now affecting translation
Mean age of first stroke is
75 years
What is the maximum difference in the time of sound arrival for the ears?
760µs https://o.quizlet.com/S0UB9gXsFh9qBQHWPWPBFg_m.jpg
_% of those with Parkinson's disease develop it before the age of 40 years
8%
Importance of stroke in the community
8k/year, 348/100k
By the age of 80 what % have hearing loss?
90% have Age Related Hearing Loss
Although OHCs outnumber IHCs, what is true about the proportion of innervation?
95% of innervation from Spiral Ganglion Cells goes to IHCs https://o.quizlet.com/iiagvFiJwAaCtSdr6g57uQ_m.jpg
Medium Spiny Neurones make up
95% of striatum
The thalamus is small. Thus damage affects?
>1 region
When did studies on how the hippocampus might store declarative memories begin?
>40 years ago
Why does K+ influx cause depolarisation of IHCs when efflux of K+ actually causes hyperpolarisation in neurons?
???? (27:25)
Postsynaptic Density
A *protein dense* specialisation attached to the postsynaptic membrane. Includes *receptors*, *scaffold proteins*, and many signaling molecules
Because LTP induction occurs in the postsynaptic membrane, Hypothesis 1 requires what?
A *retrograde messenger* to be released from the postsynaptic cell and act on the presynaptic cell to release more glutamate https://o.quizlet.com/xdc2gtygZDLx1s5QHx08Aw_m.png
Spina Bifida Cystica
A *tuft of hair*, *cyst* on their back (fluid filled). The opening can be *surgically repaired*, usually shortly after birth.
DS Ganglion Cells act as local motion detectors for
A bright stimulus moving in one direction
Parkinson's disease is multifactorial?
A combination of genetic and environmental factors
Lissencephaly
A condition in which the cortex has no sulci or gyri https://o.quizlet.com/powiy1ka8Mt7R9YUXjKQSg_m.png
Cerebral Palsy (CP)
A condition marked by impaired muscle coordination (spastic paralysis) and/or other disabilities, typically caused by damage to the brain before or at birth.
What is visual motion?
A coordinated variation of *light intensity* in both time and space in the environment
What does extended periods of low frequency stimulation (LFS, 1 Hz) of presynaptic axons result in (ans is not LTD)?
A depression of the *population* postsynaptic response (field recording)
Polymicrogyria
A developmental malformation of the human brain characterized by an excessive number of small convolutions (gyri) on the surface of the brain. https://o.quizlet.com/AW1izxA4TxtpDq.ABOw3Sg_m.png
[Diagram] A distance of about 1mm, we see less concentration of CB2 expressing cells
A distance of about 1mm, we see less concentration of CB2 expressing cells https://o.quizlet.com/tRuLwNkdP5hlc5r4pOwQiw_m.png
Tight Junctions structures comprise
A family of proteins that form a selective barrier to solutes small molecules and cells (bacteria/leukocytes etc)
Neurotrophin
A family of proteins that induce the *survival*, *development*, and *function* of *neurons* and their *circuits*
Placing the recording electrode outside of the synapses and measuring the loss of ions from the extracellular space as they move into the postsynaptic neuron is called
A field Recording
Oligodendrocytes
A glial cell similar to an astrocyte but with fewer protuberances, concerned with the production of myelin in the central nervous system
Endocannabinoid System
A group of *neuromodulatory lipids* and their receptors in the brain that are involved in a variety of physiological processes
M Cells have what kind of receptive field?
A large concentric receptive field
What is low frequency stimulation not accompanied by?
A large depolarisation https://o.quizlet.com/aEWpGVS3oTNy2x48mYi9ew_m.png
Thalamus structure?
A large ovoid (egg shaped) grey matter structure for each hemisphere
Growth Cone
A leading process with multiple branches, sense the peripheral environment
Secondary Phase Oedema
A measure of impedance, which reflects the amount of cell swelling and dying, via necrosis/apoptosis https://o.quizlet.com/om6vmX8oTfsiqA5jaTlYcA_m.png
Sensory System Attribute: Intensity
A measure of the *severity* or *amount* of the stimulus
Olfactory Bulb
A neural structure of the vertebrate forebrain involved in olfaction, or the sense of smell. https://o.quizlet.com/i/YcPNyLoQMUG_NMNNuKTK0g_m.jpg
Allo-preg-nano-lone (ALLO)
A neurosteroid that regulates HPA axis and controls stress
Modality
A particular form of sensory perception
Transduction mechanisms: Each receptor responds to
A range of stimuli to give specificity - *Specific receptors* in auditory will only respond to certain frequencies - In nose, will respond to certain chemical - In mouth, only to salt, or sweetness, to glutamate etc.
Polymicrogyria usually only affects
A small area of the cortex
P Cells have what kind of receptive field?
A small concentric receptive field
Haematoma
A solid swelling of clotted blood within the tissues.
Pathological Macroscopic anatomy of striatum and cerebrum?
A spaces forms due to atrophy, cortex tries to fill gap but is shrivelled too
Rostral Migratory Stream
A specialised migratory route found in the brain of some animals along which neuronal precursors that originated in the subventricular zone of the brain migrate to reach the main olfactory bulb
End Organs
A specialized, encapsulated ending of a peripheral sensory nerve, which acts as a receptor for a stimulus
What is the mode of AP of photoreceptor cells?
A spikeless mode (e.g. Graded)
Transient Ischemic Attack (TIA) indicate a risk for
A stroke, greatest risk in the weeks/months following TIA
The P Cell receptive field produces what kind of response that lasts as long as
A sustained, slowly adapting response, a stimulus is centered on its receptive field
Claustrum
A thin layer of grey matter in each cerebral hemisphere between the lentiform nucleus and the insula.
Proof of concept means
A trial/test that demonstrates the feasibility of the drug (i.e. improvement in function that is impaired by the disease, can include motor function (PD) and cognitive function (AD))
Primary Auditory Cortex is also called
A1 Cortex
What are (2) viral vectors used for PD neuroprotection?
AAV2-BDNF AAV2-NTRN (Neurturin) - Failed
Which serotypes are used for widespread expression in Striatum and Hippocampus?
AAV6 (Striatum) and AAV9 (Hippocampus)
Once released from the presynaptic terminal, *glutamate* binds which (3) main subtypes of glutamate receptors?
AMPA Receptors (a-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) NMDA Receptors (N-methyl-D-aspartate) *mGluR* Receptors (Metabotropic glutamate)
Which (2) glutamate receptors are often co-localised in the postsynaptic membrane?
AMPA and NMDA
What have studies shown with regards to increasing transmitter release?
AMPA receptor response increases but NMDA response does not https://o.quizlet.com/-kYKd0uPlfrDh74T0cht9w_m.png
What does tagging AMPA receptor subunits with GFP show us?
AMPA receptor subunits moving into synaptic spines with LTP induction (we see this happening in LTP)
What do phosphatases dephosphorylate?
AMPA receptors are dephosphorylated at a specific site (Serine 845) in response to LTD induction https://o.quizlet.com/-o3IbINiRI3d-f8LQQ-5Tg_m.png
What happens to pre-existing AMPA receptors during an LTP?
AMPA receptors are phosphorylated at the CaMKII phosphorylation site (Postsynaptic Density) https://o.quizlet.com/shqfL9ui8OCT3A3NnsUGAw_m.png
What gene increases risk of AD?
APOE4
Tonotopy (Not Phase Locked)
APs triggered at random locations with respect to sound wave. Auditory system has to rely on tonotopy to determine the frequency of sound *>4kHz* https://o.quizlet.com/wp2qPnUqKcpZTv7YRBQHvA_m.png
Reciprocal Inhibition occurs for flexors and extensors, but not
Abductors and Adductors
Immediate/Sensory memory
Ability to retain contemporary experiences (right now) - 1-3 seconds
Short-term/Working Memory
Ability to retain information: 15-30 seconds
Pathophysiology of Huntingtin (Htt)?
Abnormally folded version with expanded repeats - even bigger!
One Type II neuron will provide innervation to
About 10 OHCs, which are usually in the same row
Cerebral Cooling is by how many degrees and duration?
About 2-3˚ for about 3 days after brith asphyxia at term
Removing cochlear amplification weakens sound by
About 50-60dB https://o.quizlet.com/e03Ll2y-2O0HELthvAEGBw_m.jpg
ICH Hypertension
Abrupt rise in BP or chronic weakens walls until final rupture
Tests to monitor improvement of physical function include (3)
Accelerated Rotor Rod Corridor Test Morris Water Maze
Somatotopic Arrangement
According to Site of Origin
Medial-Lateral Rule
According to inferior nerves travelling more medially https://o.quizlet.com/6nWwNdp92Ef-cLgynx94JA_m.jpg
Sensory Modality
According to information carried
Metabolic Acidosis
Accumulation of Lactic Acid in blood
Respiratory Acidosis
Acidosis to do with CO2, removed by breathing
Immunotherapy can be
Active or Passive
Transduction mechanisms: Mechanical stimulus
Acts directly on cell structures to cause receptor potential
Which viruses do we use? (5)
Adenovirus (Ad) Adeno-associated Virus (AAV) (Does not elicit immune reaction) Herpes Simplex Virus (HSV) Retrovirus (RV) Lentivirus (LV)
Stroke is most common cause of prolonged
Adult disability
S/FF: Metabolism (type)
Aerobic/Anaerobic
Why are Teratogens bad for baby?
Affect oxygenation, blood flow, and nutrient provision
Both Outer and Inner hair cells have (2) innervations
Afferent and Efferent
Spiral Ganglion Neurons provide both (2) innervation to the Organ of Corti
Afferent and Efferent https://o.quizlet.com/YuLNcO-IHPHYPpBUbIm.MQ_m.jpg
Majority of _____ axons synapse on IHC and majority of _____ axons synapse on OHC
Afferent, Efferent
Sources: Muscle Receptors
Afferents from muscle spindles
How do we interpret motion?
After *integration* of visual information processed in *discrete* pathways in the retina
Common with advancing?
Age
Sense of smell declines with
Age
AD more prevalent with
Age (but not part of normal ageing)
What is the ageing population pathway?
Ageing population → ↑Neurodegenerative disease incidence → Social and economic impact
Types of Complex Deficits (2)
Agraphesthesia and Somatosensory Agnosia
What types of inflammation do Microglial Cells respond to?
All kinds, central such as the neurons dying or external inflammation
Focal Cystic Necrosis (Cystic Lesions/Holes)
All tissue missing (holes - cystic) (white matter) https://o.quizlet.com/7u.CioBmwSIoeqDZOheXEw_m.jpg
Where are declarative memories stored?
Alongside a sense in the cortex https://o.quizlet.com/sWnuaUDsH0Ofd89RTS8p.w_m.jpg
Operant Conditioning
Alter probability of a response by associating it with a reward/punishment
LTP is a known mechanism for
Altering connections within networks of neurons https://o.quizlet.com/8O1Ci2sQwdtPu077Ok6p1A_m.jpg
When do and don't S Type motor unit fire APs?
Always, except REM sleep
Most Common Dementia
Alzheimer's Disease (AD) https://o.quizlet.com/1xeE2aSrOuH211BIaTnNRw_m.jpg
Consumption of this antibiotic causes gradual patched loss of sensory hair cells
Aminoglycoside ototoxicity https://o.quizlet.com/S8o.MkktQIqIKRu1703Dvw_m.png
Sensory systems provide information on (3) aspects of the stimulus
Amount, duration and location
What do we add to inhibit clathrin mediated endocytosis and what happens?
AmphiSH3, LTD-induced endocytosis of AMPA receptors is prevented
HM - which structures were removed? (4)
Amygdala, *incus*, *hippocampal gyrus* and anterior hippocampus removed (alleviate epilepsy) https://o.quizlet.com/6k6YuDjt6kQ2LdNqJkz9CA_m.jpg
Amyloid is cleaved from which protein, on which CS?
Amyloid precursor protein (APP) on CS21
In the diseased state of Lissencephaly, what is the grey matter like?
An amorphous spread of grey matter
Vomeronasal Organ (VNO)
An auxiliary olfactory sense organ that is found in many animals, mainly used to *detect pheromones*, chemical messengers that carry information between individuals of the same species
What is the difference between Parenchymal and Perivascular Microglial Cells?
An example of similar microglial cells that are slightly different in function. Parenchymal function in the *ECF *and the perivascular (as the name suggests) wrap themselves around the blood vessel for some function https://o.quizlet.com/BfzkOlJf.TQQrJt-EBJDIQ_m.png
Aneurysm
An excessive localized swelling of the wall of an artery
What have studies shown after LTP is induced?
An increase in synapse number
What should we see if transmitter release is increased during LTP?
An increase in the size of the AMPA and the NMDA responses with LTP induction
What is a Stem Cell?
An undifferentiated cell which can give rise to more cells of the same type (proliferation) and/or more restricted potential cells (differentiation)
Metabolic Acidosis can occur during
Anaerobic metabolism during hypoxia
Studies of synapse plasticity in the awake behaving animal were first performed on
Anaesthetised rabbits
Motor Unit
Anatomical and functional unit of the motor system https://o.quizlet.com/Bn4dQmS8JxHvhRXxKFk65A_m.jpg
Failure of the anterior end of the neural tube to close is
Anencephaly
Myotatic Reflex Receptors
Annulospiral Endings wrapped around intrafusal muscle fibre
Intrafusal Fibre belly has what wrapped around it?
Annulospiral Sensory Afferents
How are the Cochlear Nucleus and other structures in the auditory pathway also systematically/tonotopically organised?
Anterior - Cell bodies for lower frequency neurons Posterior - Cell bodies for higher frequency neurons https://o.quizlet.com/Nwa217SYWieJrR02A1OEUw_m.jpg
What are the (2) Spinocerebellar Tracts?
Anterior and Posterior https://o.quizlet.com/C7KN.x00qw2NiSke6lEYYw_m.png
Where are motor nuclei in spinal cord?
Anterior horn of the grey matter (Rexed's Lamina IX)
When BMP4 is inhibited what forms?
Anterior neuroectoderm forms (the brain)
Minocycline
Antibiotic, helps but trials say its shit
Microglial Cells may present _____ to other _____ cells
Antigen (APCs) to other immune cells
Latrepirdine
Antihistamine, free radical scavenger effect
Coenzyme Q/Q10
Antioxidants, but need to consume a lot to have effect
Perinatal Brain Injury
Any injury that occurs near birth
In a visual field defect, the lesion may be where?
Anywhere along the optic pathway; retina to occipital cortex https://o.quizlet.com/kjB-9Ujel-tlCgmdzF8PdA_m.jpg
Which side of the endothelial cells face the blood - apical or basolateral?
Apical
In some situations, the degree of ischaemia is not severe enough to cause necrosis of neurons, but may trigger
Apoptosis
In the latent phase, what is happening regarding apoptotic pathways?
Apoptotic pathways take some time to manifest, so intermediates involved in these pathways increase during this latent phase, which is why we observe damage in the secondary phase (because the apoptotic pathways are finally active)
What do you do to caged calcium in the postsynaptic cell to release it? What happens next?
Apply a flash of light - will trigger LTP https://o.quizlet.com/R68zGlNAo4EaxTHGJX8Tfw_m.png
Are regulating directionally selective ganglion cells in response to centrifugal movement???
Are regulating directionally selective ganglion cells in response to centrifugal movement???
Common: Dermatomes
Area innervated by single dorsal root (diverging perspective) Sum of the receptive fields of the primary afferents (converging perspective)
What is the role of Pairing?
Artificially depolarising the postsynaptic cell while the presynaptic cell is releasing glutamate
How is HD fatal? (Term and def.)
Aspiration Pneumonia - loss of control of swallowing muscle
Audiometry (2)
Assessment of hearing threshold, objective and subjective methods
ICH Cerebral Amyloid Angiopathy (CAA)
Associated with Alzheimers, Aß deposit in vessel walls
Inducing LTP with both stimulation of the presynaptic cell AND depolarisation of the postsynaptic cell (NMDA Receptor) is called? (Not pairing)
Associativity or Co-operativity
When do babies get brain injury? Historically?
Assumed to be during or shortly after birth
What happens to someone with neuroinflammation?
Astrocytes are activated
What happens if you co-culture astrocytes and neuronal cells in hypoxic/ischemic/low glucose conditions?
Astrocytes can live in this condition for quite some time but neurons die
What else surround the blood vessels?
Astrocytic *end feet* (the terminal regions of astrocytic processes) surround the outside of capillary endothelial cells
Cardinal Clinical Features are often _____ at onset
Asymmetric (one hand tremor, poor arm swing on one side)
Type I: Excitatory Synapses are also called
Asymmetric - Postsynaptic density is very dense
Progression of AD
Asymptomatic -> MCI -> Dementia
How is NMDA receptor voltage gated?
At *resting membrane potential*, it has bound to it Mg2+ that keeps it in the inactive state. So binding of glutamate alone will not activate it.
How fast do the neurons proliferate?
At Week 3 few hundred cells become 320 billion at Week 12
Mechanically remove thrombus
At highly specialised centers - Groin Puncture within 6 hours of stroke
There are how many different representations of the visual world embodied at a separate sublayer of the inner plexiform layer?
At least a dozen
Where do the leukocytes traveling along the endothelium attach and form adhesions?
At the density of adhesion molecules
Information Processing
At the level of the retina and the brain
The rods and cones are situated where in the retina?
At the most posterior part (behind all the retinal layers) https://o.quizlet.com/omc0T1ral4b14ptNOFgl2g_m.png
Sources of emboli in the heart (4)
Atrial fibrillation Heart valve diseases Myocardial infarct Endocarditis (heart valve infection)
Macroscopic Pathology of HD?
Atrophy/cell death of Brain Structures https://o.quizlet.com/yS2xRES5kYF6gHo-73ZhRw_m.png
What allows you to convert Immediate/Sensory memory into Short-term/Working Memory?
Attention (focus on stimulus from information coming from all directions)
What do chemokines do?
Attract other immune cells to site of damage
Name for sound cortex?
Auditory Cortex
First wave represents the activity of the
Auditory Nerve
MS is an _____ disease
Autoimmune
Genetic CS6
Autosomal recessive form of PD, young onset, mutations on CS6 gene for parkin protein, homologus with ubiquitin
So, what is the trigger for LTP?
Available calcium
Declarative Memory
Available to consciousness and can be expressed by language (i.e. can be declared)
Conscious Proprioception
Awareness of body position Control of voluntary movements
Somites are precursors of the
Axial musculature and skeleton
Which synapse is formed between axons?
Axo-axonic Synapses
What is a Classic Synapse?
Axo-dendritic Synapses
Which synapse is often Inhibitory?
Axo-somatic Synapses
Synaptogenesis takes place as
Axons and denrites grow
Primary Somatosensory Cortex (S1) is the major receiver of
Axons from thalamus https://o.quizlet.com/k3YfVd-ixa8KFOZV6rbDTg_m.jpg
Flexion (withdrawal) Reflex Efferent
Axons of αMNs
Reverse (Inverse) Myotatic Reflex Efferents
Axons of αMNs
What is the microscopic pathology?
Aß Plaques and Neurofibrillary Tangles (Tau)
Passive Immunotherapy
Aß antibody direct injection. Made in mice then humanised
Active Immunotherapy
Aß vaccination - body produces its own antibodies
TRPM8 (Cold) are carried by
Aδ (III) Fibres
Which (2) fibers carry pain sensation?
Aδ (III) Fibres C (IV) Fibres
What are (2) Aδ types?
Aδ Mechano-sensitive Nocioreceptors Aδ Mechano-thermal Nocioreceptors
Risk factors for Ischemic Strokes and TIAs
BP, smoking, cholesterol, exercise, diabetes
Which factors affect our recognition of an image in our visual field? (4)
Background Illumination Spatial Frequency Wavelength Dark Adaptation
Ethical limitations of Germline Gene Therapy?
Banned in many countries - we are modifying human DNA - what is the limit? Make super babies? What is the perfect human?
What cell type is found in the olfactory epithelium? What do they do?
Basal Cells - constant turnover of olfactory sensory neurons
What cells are found at the base of taste buds?
Basal cells https://o.quizlet.com/GPfTS0R93bBZ8NAnmsGpNg_m.jpg
Procedural memory associated with which CNS structure?
Basal ganglia
Olfaction and gustation are known to be the most _____ senses
Base Senses
How is the basilar membrane tonotopically mapped (structurally)?
Base is narrow, stiff and thick -> widens as you go towards the apex (5x wider, floppy and thin) https://o.quizlet.com/4V8eIbnIOd6s93qib0Omgg_m.jpg
Diagnosis and confirmation of AD?
Based on dementia rating, but confirmation only post mortem
Synapses are the ______ _____ _____ of the brain
Basic processing units
The scala media and scala tympani are separated by?
Basilar Membrane
What is the most important structure for frequency encoding in the cochlea?
Basilar Membrane
What are (2) other names for the Crus Cerebri
Basis Pedunculi or Cerebral Peduncle
Why is the cholinergic system a target?
Because ACh deficit in AD underlies AD symptoms (i.e. behaviour and cognition impairment)
Why does LTP induction require both presynaptic transmitter release and postsynaptic depolarisation?
Because the induction of LTP is dependent on calcium influx (and Ca influx is via NMDA receptors)
Why are Interneurons inhibitory?
Because they release inhibitory neurotransmitters
Why is a loss of astrocytic neuronal support bad?
Because they serve a protective/support role in the brain for neurons
Why do we need to treat the assumption of LTP = memory with caution?
Because we don't yet have specific experiments that can directly show that LTP occurs during learning and memory
Why does myelination occur so late in development?
Because you have some *postnatal manipulation* of the nervous system, so early myelination would hinder this
Dendritic Growth begins _____ and continues _____
Begins prenatally and continues postnatally
What happens to the neural plate?
Begins to fold at the midline, forming the *neural groove* and *neural crests*. https://o.quizlet.com/MCGW.vnH1l0LiZqIvD3gOQ_m.png
Once induced, how do we examine that our model animal is depressed?
Behaviour Testing
Emotional Problems include
Behaviour and Cognitive Changes
Secondary Visual Cortex
Behind the Primary Visual Cortex, interprets the information from the Primary Visual Cortex - data is analysed.
Intrafusal Fibres parts (2)
Belly and Non-belly sections
What are the benefits and downsides of a whole cell recording?
Benefit: We get precise information Downside: We don't know what is happening to the neuron's buddies (in the vicinity)
Common: Decussation. Why?
Better separation of tracts - more robust than same side wiring
Projection Fibres (1 example)
Between brain and spinal cord/muscle, *Internal Capsule*
Reciprocal Inhibition
Between flexors and antagonist, when one is flexed due to reflex, the other is relaxed
Commissural Fibres (3 examples)
Between two hemispheres, *Corpus Callosum*, Anterior and Posterior Commissure
What were the treatment groups in this experiment?
Big friendly group SI/ ALLO SI/Fluoxetine (Prozac) (known to work) SI/placebo (sugar pill)
HM had what kind of lobotomy?
Bilateral (Both sides) Medial Temporal Lobe Resection
Dopamine agonists
Bind dopamine receptors
(B) G-Protein Coupled Receptors - modulatory
Binding of neurotransmitter causes *conformation *change in channel -> pathway involving intracellular messengers which open up ion channel in close vicinity https://o.quizlet.com/YTMAorZ3rWvXqwl.6rm2RA_m.png
(A) Transmitter/Ligand Gated Ion Channels - Rapid
Binding of neurotransmitter causes conformation change in channel, allowing the influx of ions https://o.quizlet.com/17znSNUwtgiIiFLr8gYZmw_m.png
Photoreceptors synapse directly onto
Bipolar Cells
Preterm
Birth before 37 weeks of gestation
What are overlapping regions of taste specificity on the tongue?
Bitter (Back) Sour (sides Sweet/Umami (meaty) (front and sides) Salty (edges around the tongue) https://o.quizlet.com/xcKFpMNoL2W7dAj5U0vl4w_m.png
Stage Theory: What is the *third* group of neurons in the neural stage?
Black and White, input from RGB but do not report to colour but *intensity/brightness*
Subarachnoid Haemorrhage (SAH)
Bleeding between arachnoid matter and pia matter Higher in women
How can we reduce hearing loss by at least 50% with regards to glutamate excitotoxicity?
Blocking glutamate receptors prior to noise exposure
What happens if you apply NMDA receptor blockers during LTD induction?
Blocks LTD (APV is the blocker of NMDA) https://o.quizlet.com/pvm0eNKxdV9CxPTeHSQshg_m.png
Intracerebral Haemorrhage (ICH)
Blood leaking into brain Asians
What are the (3) types of cones?
Blue, Green and Red responsive https://o.quizlet.com/510UXW5RAXyy1e4nMmkLXA_m.jpg
Stage Theory: What is the *first* group of neurons in the neural stage?
Blue-Yellow processing B Cones GR Cones (yellow) inhibit the B Cones
Accessory olfactory systems are important for bonding which (2) entities?
Bonding mother and baby
BMP
Bone Morphogenetic Protein
Thalamus recevies information from
Both Discriminative and Non-Descriminative Pathways
Auditory nuclei in the brainstem (Superior Olivary Complex) receive input from
Both ears (Binaural Hearing - for sound localisation)
Seeing motion is an activity of the
Brain
BDNF
Brain Derived Neurotrophic Factor https://o.quizlet.com/N7PsY.b8bVvbZnbQDAMtvg_m.jpg
Ectoderm forms (2)
Brain and Skin
Where are Microglial Cells found?
Brain and spinal cord
AD macroscopic pathology? (specific)
Brain atrophy Widening of sulci Thinning of cortex Ventriculomegaly https://o.quizlet.com/RNLs5wBHXtObBedUf-H7bw_m.png
Where else is taste specificity mapped?
Brain https://o.quizlet.com/XcHpJDp1a5nthF5LkW2ZTw_m.png
Receptive field of touch receptors: What happens if you get a pin and prick yourself of the back of your hand?
Brain will see that this neuron is getting activated mostly, so that is the precise location of the stimulus https://o.quizlet.com/75zSFQpI0-JKXcCq7KDerg_m.png
The most commonly used technique in humans (objective method) is recording of the
Brainstem Auditory Evoked Potentials (BAEPs)
What happens if we hear a loud sound?
Brainstem will tell the OHCs to reduce the amplification of the sound for the IHCs
Remaining dendritic branches continue to
Branch and lengthen
What do Free Radicals do? (3)
Break down lipid/protein molecules (lipid bilayer), damage DNA, and trigger apoptosis https://o.quizlet.com/ysFoybVZUVmSduN.jXMAnQ_m.jpg
Rhythmic Motor Patterns include? (3)
Breathing, locomotion, chewing
Tetanic Stimualtion
Brief bursts of high frequency stimulation (100 Hz) to presynaptic axons for 1 minute
Why termed diffuse (white matter injury)?
Broad regions of cell death/white matter atrophy
How can we cause LTP in the contralateral hippocampus? What is this known as?
By applying similar repetitive stimulation to that side - Specificity
How was GDNF initially administered?
By infusion
How do we define a change in synaptic strength?
By measuring the size (amplitude) of the postsynaptic AMPA receptor *current* (AMPAR EPSC) https://o.quizlet.com/QA0hZruoi2s.bCltriyYYQ_m.png
How does the stapes transmit vibrations onto the cochlea?
By moving the cochlear fluids, which will end up in the frequency specific regions of the cochlea
How do we measure an increase in synapse strength?
By observing the increase in the amplitude of the postsynaptic response
What happens to the afferent axons from the *Dorsal* Cochlear Nucleus?
Bypass the Superior Olivary Complex and merge with the lateral lemniscus at the level of the inferior colliculus
TRPV3/4 (Warm) are carreid by
C (IV) Fibres
Schaffer Collaterals
CA3 Pyramidal Cell Neurons -> CA1 Pyramidal Neurons
This means LTP requires
CAMKII *phosphorylation* of AMPA receptor vesicles!!!!
The insertion of AMPA receptor subunits into synaptic spines depends on?
CAMKII phosphorylation of AMPA receptor vesicles
Is CB1 or CB2 bigger?
CB1 https://o.quizlet.com/MBAO1mu7SaujvDvGfJG8Wg_m.png
What is the most abundantly expressed receptor in brain?
CB1R
What did we see in rodent models with regards to CB2 receptor activation?
CB2 receptor activation reduced the level of *neuroinflammation* and the amount of *leukocyte migration* into those brains (pre-clinical studies)
ICAM →
CD11a, CD11b, CD11c
E Selectin (CD62e) →
CD15s CD162
P Selectin (CD62p) →
CD24 CD162
VCAM →
CD49d/CD29 (VLA4)
Neural tube becomes
CNS https://o.quizlet.com/1RW.AQf4cuprezjhkvwBYA_m.png
CB1 Receptor
CNS neurotransmission - highly expressed in mammalian CNS
Impaired waste removal
CO2 accumulation → Respiratory Acidosis
What takes up the space in Ventriculomegaly?
CSF
Diagnostic tools used?
CT, MRI, PET, CSF, Blood
How to distinguish ICH from stroke?
CT/MRI scan
Which (2) drugs get passed the BBB?
Caffeine and Alcohol
The neurons that move up the Radial Glial Fibers get to the marginal zone and come into contact with what cells?
Cajal Retzius Cells
Which *proteins* are important for the formation of the Cortex? (3)
Calbindin, Neuropeptide Y an Parvalbumin
CaMKII
Calcium calmodulin-dependent protein kinase II
Like LTP, what does LTD depend on?
Calcium influx through NMDA receptors
Intra-nerve damage
Can be damage of fibres within 1 nerve
How is MPTP useful?
Can be used to make disease models (i.e. mice with PD)
Pluripotent
Can generate any body cell type (from embryo/fetus)
How is NIRS (Near Infrared Spectroscopy) used?
Can measure the cerebral *oxidative state* of *CytC Oxidase* and thus the rate of OM
Gene Promoters
Can use cell specific promoters to stimulate transcription of genes in specific cells (e.g. only in neurons)
Agraphesthesia
Can't recognise specific cutaneous sensation (e.g. will recognise someone drawing on their arm, but not what they drew)
Common techniques used to monitor the different phases of injury?
Cardiorespiratory function, BP, HR, blood oxygenation etc
What did these repetitive trains of stimuli do to the Dentate Gyrus Cells at the other end? (i.e. how did we record it the change)
Caused an increase in the amplitude of the *population* synaptic response (Field potential recording) - The cells began to take in more ions
Good animal models for depression must have symptoms...
Caused by the same conditions that trigger human depression (i.e. stress)
How is loss of motivation manifested in the Forced Swim Test?
Cbf'd swimming anymore to get out of the water
Cellular Homeostasis
Cell ability to maintain normal function in variable conditions
Grey matter is made of (2)
Cell bodies and Nuclei
𝛾 Motor Neurons cell bodies location?
Cell bodies same location as alpha (ventral horn) https://o.quizlet.com/1-qhBOQuDCV564mtz.OiSw_m.jpg
Uncontrolled Seizures and Abnormal brain activity leads to (3)
Cell can swell/lyse (↑internal osmolarity) Excitotoxicity Oxidative stress
What is Reelin Deficiency pathophysiology?
Cells can migrate but don't get a hop off cue. *Radial fibres retract* and the stem cells are dispersed all over the place
Why is blocking the removal of PSA bad?
Cells can't make connections so it dies!
After implanting the false memory, what could we observe with the c-fos?
Cells in amygdala recruited (emotion) -> false memory as strong as a natural memory
Embryonic Stem Cells refer to
Cells that can form only the baby
In MS, the immune system attacks what through which mechanism?
Cells with myelin - Auto antibodies to the myelin
Core Ischemic Zone
Central - Most severe ischemia → irreversible necrosis
Non-Declarative: Long Term located
Cerebellum, basal ganglia premotor cortex, other motor sites
Only medical intervention Start early after insult for maximum effect Safe for term babies (not preterm)
Cerebral Cooling
How can we protect the brain from apoptotic pathways and their manifestation in the secondary phase?
Cerebral Cooling in the latent phase to slow down the increase in apoptotic intermediates
What is relatively unaffected in Preterm Perinatal Brain Injury?
Cerebral Cortex/Grey Matter
Long Term Memory Storage is distributed through
Cerebral cortex
The forebrain is made up of (3)
Cerebral hemispheres, thalamus, and hypothalamus
Brain Structures Include (5)
Cerebrum Caudate nucleus + putamen (striatum) Globus pallidus (i+e) Subthalamic nucleus Substantia nigra (midbrain)
Demntia symptoms
Changes in personality, mood, and behaviour
Synaptic Plasticity is the (3) of synpatic connections
Changes, growth and reordering
ChR2
Channel Rhodopsin From algae - Channel opens when stimulated with blue light → Na+ influx → AP elicited → cell activated https://o.quizlet.com/pgpq1UO9Avm.VNoHG84GYQ_m.jpg
What are Gate Keeping Moments in Nervous System Development?
Checkpoints, that if are not passed, spontaneous abortion takes place
The electromagnetic signal (light) is converted into
Chemical and Electrical signals
Transduction mechanism of *bitter, sweet and umami* (Type 2 Cells)
Chemical binds G Protein Receptor -> Activates *Phospholipase C -> Converts IP2 to IP3* -> Na channels open, depolarisation -> Voltage-gated calcium channels (*internal* calcium stores) release calcium -> Release neurotransmitter *ATP* (glutamate? serotonin may act as modulator) https://o.quizlet.com/pcNDOrqJD5H2UXa7S-DGTg_m.png
Which sense is the oldest and most common sensory system?
Chemical senses - even brainless bacteria can detect and react to chemicals in the environment (chemotaxis)
Taste and Smell
Chemicals that are in the environment are dissolved into the nose (mucous) or tongue/roof of mouth, pharynx (saliva), these interact with the receptors https://o.quizlet.com/eA34pRJOGaY9q5MYhlGdRQ_m.png
What is a particular cytokine subclass they secrete?
Chemokine
(2) Examples of 2nd messenger systems?
Chemoreceptors in olfactory epithelium Photoreceptors in retina
How can we record field potentials in awake, behaving animals?
Chronically implant electrodes into hippocampi https://o.quizlet.com/R5wiwlmuKsBdNP0llcHstg_m.png
What reduces the risk of developing Parkinson's disease by 50%?
Cigarette smoking
Sensory System Attribute: Modality (type)
Class of stimulus (sight or sound or etc...)
AMPA receptors co-localise with
Clathrin-coated pits (immunocytochemistry)
By which mechanism are AMPA receptors removed from the synaptic membrane?
Clathrin-mediated endocytosis
Which specific transmembrane proteins contribute to tight junctions?
Claudins 3 and 5
Treatment of aneurysms? (2)
Clip around neck Occluding with coils or baloon
Taste Buds
Clusters of *bulbous nerve endings* on the tongue and in the lining of the mouth which provide the sense of taste
α & 𝛾 motor neurons are always
Co-Activated, with 𝛾 first
Sensory Transduction: Stage 3 (Name of what the OHCs do?)
Cochlear Amplification - characterised by the contraction of the outer hair cells
Hearing loss from noise, aminoglycoside antibiotics, ototoxic anticancer drugs and aging all contribute to
Cochlear Oxidative Stress
The M Cells are not sensitive to
Colour
P Cells are (colour)?
Colour Sensitive
Iris
Coloured part of the eye behind the cornea, adjustable circular opening https://o.quizlet.com/i/ZsbhD7Npw6SrKYwDPHqCyA_m.jpg
What do we need to do in future studies?
Combine both the cellular and behavioural levels
Common Features of the Somatosensory System begin here
Common Features of the Somatosensory System
αMNs serve as the Final
Common Path
What happens if you add protein phosphatase inhibitors into your in vitro experiment?
Completely blocks LTD
The main role of the Auditory Cortex is to analyse
Complex Sounds
Late Complications of Parkinson's Disease (5)
Confusion, hallucinations (due to drugs) Dementia Emotional disturbances (anxiety, depression) Postural hypotension Motor Fluctuations
What are (2) classes of Proprioception?
Conscious and Unconscious
Detection of the internal and external environment leads to
Conscious awareness of environment and environmental events
Immediate/working memory enters long-term via (i.e. how do you learn)
Conscious or unconscious rehearsal
Stage Theory: Receptor Stage
Consists of the three photopigments (blue, green and red cones) - Trichromactic
Memory Storage is known as
Consolidation
Sensory loss would be loss of
Contact with environment
Sensory systems allow us to maintain
Contact with the environment
Synaptic vesicles
Contain the chemical neurotransmitter
Intrafusal Fibre Non-belly sections contain
Contractile Elements
Intrafusal fibres have what kind of elements?
Contractile Elements, actin and myosin, in the non-belly part
Damage to cortex leads to loss of sensation on which side?
Contralateral
What is used as a control?
Contralateral hippocampus (taking advantage of specificity)
Factors: Background Illumination
Contrast of object against background
Final Common Path
Converging excitatory and inhibitory synaptic inputs from other areas of the CNS/PNS → α MNs (to regulate movement) https://o.quizlet.com/mfvhU-6LI6ePDu61l-HV.g_m.jpg
What do chemical signals do?
Convert electrical signals to chemical signals to allow communication between neurons
What does the postsynaptic cell do to the chemical signal?
Converts the chemical signal back into an electrical signal in the postsynaptic cell
Somatosensory System
Conveys information about state of body proper and immediate environment https://o.quizlet.com/-ne2WKQCznqjrPMJrWRhRw_m.jpg
Subjective Methods
Cooperation of individual being tested, relies on subject's perception and response to sound
Cerebellum for
Coordination, precision + accurate timing
Posterior Cord Syndrome and Anterior Cord Syndrome can be due to damage to (2)
Cord or spinal artery
Two zones distal to artery occlusion
Core Ischemic Zone and Ischaemic penumbra
What are (3) other names for the Tectum?
Corpora Quadrigemina, Superior/Inferior Colliculus or Roof Plate
What is lateral to the Extreme Capsule? (2)
Cortical Grey Matter of the insular cortex and the temporal Operculum
We see movement due to
Cortical integration of information coming from the eyes
Sources: Descending Tracts
Corticospinal, Reticulospinal and Vestibulospinal
Find Engram: Step 1 - Create?
Create a memory (beep and shock) https://o.quizlet.com/Ip0t4npKJVj6mt6UsW74Pg_m.jpg
Which plate is below the olfactory bulb?
Cribriform Plate
Braille: What is the 'visual cortex used for somatosensory input' phenomenon termed?
Cross Modal Plasticity
Activation of Extension Motor Neurons (midline) in the contralateral limb to maintain stability is called...
Crossed Extension Reflex https://o.quizlet.com/1NtpKyjVaVqciYw72GKQog_m.jpg
Anterior Cord Syndrome
Crude touch, pressure, pain lost Proprioception/discriminative touch remains Possible loss of motor https://o.quizlet.com/QNNUG7UbEHT5VV8QHhs4oQ_m.jpg
Whole cell recordings measure
Current flow into *a* neuron
Difficulties: Measurement of synaptic changes in multiple pathways in behaving animals is
Currently beyond our methodological abilities
Karl Lashley's Experiment (1920's)
Cut away bits of the brain (incrementally increasing) → larger lesion = worse performance https://o.quizlet.com/FpIRkyEhkL.1MfSmeRbvvw_m.jpg
If dendrites or axons do not make appropriate connections, they are
Cut off
Brodmann Areas 1, 3b
Cutaneous
Brodmann Area 2
Cutaneous and Proprioceptive
Stereocilia
Cylindrical protrusions
Astrocytes can produce and respond to
Cytokines/Chemokines
The above DSGCs are different from
DSGCs that detect stimuli moving in the opposite direction
AMPA receptor-mediated Excitatory Postsynaptic Current (EPSC)
Dafaq? https://o.quizlet.com/wx9tKH3CwNKoih4pmBEmQQ_m.png
Somatosensory Agnosia
Damage in areas that connect visual and somatosensory → cant identify object without visual input
Inflammation can result in more
Damage than repair of the tissue
Stroke
Damage to brain or spinal cord caused by abnormality of blood supply
Multiple Sclerosis
Damage to the sheaths of nerve cells
Chorea
Dance like, involuntary movement in wake state
Pupil
Dark circular opening in the center of the iris (varies in size to regulate light in) https://o.quizlet.com/i/QIf88RI1e8ldqFRla_hoiQ_m.jpg
What type of memory does synapse plasticity underlie?
Declarative (explicit) memory (names and facts)
Modes of memory (2)
Declarative and Non-Declarative
RB had loss of what kinds of memories?
Declarative, episodic memories
Why is phosphorylation of proteins beneficial?
Decreases further need for calcium influx
How does induction of long-term depression (LTD) affect the amplitude of AMPA EPSC?
Decreases them in size - makes them less negative https://o.quizlet.com/eOoEVlTgNCSoL3fmqBQYDQ_m.png
Inhibition Therapy can be compared to
Deep Brain Stimulation, which also attempt to reset the overexcitabilty imbalance
Surgical treatments (4)
Deep brain stimulation Stereotactic thalamotomy Stereotactic pallidotomy Transplantation of dopamine-producing tissue (e.g. fetal tissue)
Parkinson's Disease
Degeneration of dopaminergic neurons in the striatum → ↓release of dopamine (DA) in striatum → imbalance of DA/ACh → ↑excitability → tremors etc.
Perirhinal Cortex Lesions test
Delayed Matching and Non-Matching to Sample (DMS and DNMS) https://o.quizlet.com/I3TW4op..eOkfD7f5TjbUw_m.jpg
AD symptoms
Dementia, memory loss, plaques and tangels
Excitatory synapses are found on
Dendritic Spines, can support one or several synapses https://o.quizlet.com/-wT5TQeY95ICtNR7YnqGPQ_m.png
Mossy Fibres
Dentate Gyrus Neurons -> CA3 Pyramidal Cell Neurons
Sensory Transduction: Stage 4
Depolarisation of the IHCs
Sensory Transduction: Stage 2
Depolarisation of the OHCs - opening of the transduction channels due to movement of stereocilia
What happens when an AP invades the *presynaptic* terminal?
Depolarisation of the presynaptic membrane https://o.quizlet.com/tSvw7UGT6LQCLRc-18aEGw_m.png
Inner Hair Cells IHC (function and shape)
Depolarisation of these cells will transfer sound information to the brain, *oval* shaped https://o.quizlet.com/7wFHDrRyQs60f0qk33o6Hw_m.png
Fovea
Depression in retina - centre of visual field https://o.quizlet.com/i/SoBarXgX2NX5jdpeo-90lw_m.jpg
Neuromuscular Spindle do what?
Detect rate and size of changes in length of muscle https://o.quizlet.com/-KyNQ6RPN7NJG8c20Kmyug_m.jpg
Factors: Wavelength
Detection by photoreceptors (colours)
Sensation
Detection of physical stimulus
How does the cochlea in the ear work?
Detects sound in space (3D) -> Coiled cochlea has a line of cells, and each cell responds to a different frequency. If the frequency appears in that sound, it will stimulate the specific band of cells, and they will convey that information
Huntingtin (Htt) is mostly important for?
Development
(3) ways to diagnose and locate ruptured aneurysm?
Diagnose with CT Lumbar puncture - CSF blood staining Cerebral Angiography to locate
Different types of afferent fibers decrease in which (3) aspects from I → IV?
Diameter Myelination Conduction Velocity
Muscle Spindles are not present where? (2)
Diaphragm/facial muscles
Colour blindness is also known as
Dichromacy
Growth Cones seek out
Different *gradients* of *growth factors* (chemical and electrical gradietns) that will attract them, so groups of cells will find their home in a particular area of the brain
How are Astrocytes different?
Different Origin
Where are motor nuclei in the brainstem? Connect to muscles through?
Different parts of the brain stem which connect to muscles through cranial nerves
What are the other 4 waves?
Different processing centers in the brainstem to the inferior colliculus
Abnormal postural reflexes (4)
Difficulty rising from chair or rolling over in bed Stooped posture Several steps to turn Falling
Individual Unitary Potentials
Direct recording, from a single cell or nerve fibre (single unit potential) - Technique not used in humans https://o.quizlet.com/EuVnxMh23ltprm.5btC8Yg_m.jpg
DS Ganglion Cells are
Direction-Selective Ganglion Cells
Dorsal Column/Medial Lemniscus Tract - Type of sensation
Discriminative Pathway Fine Touch and Pressure, Proprioception
What can cause the aneurysms that cause SAH? (5)
Disease of CT Genetic Smoking High BP High Alcohol
2 Point Discrimination of Receptive Field? (Describe, example, analogy)
Distinguish between 2 adjacent points Small for fingers, large for belly Like resolution https://o.quizlet.com/qok4S8AilEh4hlUANxZqGg_m.jpg
Memantine has side effects yeah?
Dizziness, headache, confusion etc.
What is special about the Mesencephalon?
Does not develop into further structures (besides the formation of colliculi). This explains why we have big cerebral hemispheres and hind brain, but small midbrain.
*Hue*
Dominant wavelength
What are some Cholinesterase inhibitors?
Donepezil or Rivastigmine
Loss of these neurons results in loss of what to where?
Dopamine to the straitum
DARP32 an Meis2 tell the cells to become responsive to (3) and produce a lot of (1)
Dopamine, Glutamate and GABA and produce a lot of GABA
Which cells (located where) die in particular?
Dopaminergic Neurons in Substantia Nigra
What are the (2) somatosensory pathways?
Dorsal Column/Medial Lemniscus Tract Anterior/Lateral Spinothalamic Tract
In the Myotatic Reflex, a branch of the Ia Afferent goes to
Dorsal Spinocerebellar Tract Cells (so brain is also notified)
What are the (2) pathways that receive somewhat integrated information from the eyes?
Dorsal and Ventral Pathways/Streams
ON/OFF DSGCs can be divided into 4 types, differing in which (4) directional preferences?
Dorsal, ventral, nasal or temporal
The Dorsal and Ventral horns contain
Dorsal: Sensory Nuclei Ventral: Motor Nuclei
Dementia is reversible when the disease is due to?
Drugs or hormonal
Teratogens
Drugs, alcohol, smoking, carbon monoxide
2 processes for localizing sound in the horizontal plane: (1) Interaural Time Delay (20-2,000Hz) (2) Interaural Intensity Difference (2,000-20,000Hz) What is this theory called?
Duplex Theory
Short-term/Working Memory is limited in (2)
Duration and Capacity
Behaviour Animal Model
E.g. socially isolate animals to model depresseion
Neurons that respond to Interaural Intensity Difference (High Frequency Sound)
EE is both ears and EI is contralateral ear only https://o.quizlet.com/gYHlFEq.p7wTHH4b66u6qQ_m.jpg
Not so common techniques used to monitor the different phases of injury? (take too long)
EEG MRI NIRS (Brain oxygenation) Doppler (Blood flow)
What can we use to chelate (bind up) intracellular calcium ?
EGTA - Inhibits LTP
What happens to the vibrations that travel through the basilar membrane?
Each wave reaches its maximal amplitude at the position appropriate for the frequency of stimulation, *then* rapidly declines in size as it advances toward the cochlear apex https://o.quizlet.com/hnnBUqWUqV66URSIFXiY0g_m.jpg
Phases of LTP (3)
Early, Intermediate and Late https://o.quizlet.com/ZNN8enRlv3SRFw.t1Dlh3g_m.jpg
What is the phagocytic role of Microglial Cells?
Eating cells or cellular debris where other cells have died, cell turnover
Brain and skin are made of which germ layer?
Ectoderm
Formation of the notochord?
Ectoderm surface indentation called the *Primitive Pit* leads the formation of the lagging *Primitive Streak*, which is a migratory structure. https://o.quizlet.com/fenggXq.rpD8O634kxyUEg_m.png
BMP4 alone induces which germ layer to become what?
Ectoderm to become *Epidermal Cells*, (instead of forming brain, it forms skin)
What are the (3) germ layers?
Ectoderm, Mesoderm and Endoderm
Crystalline Lens
Elastic structure behind iris, focuses light to retina by changing shape https://o.quizlet.com/R3wZFnfRryjOXjniPz7cxw_m.jpg
Objective Methods: Auditory Potentials
Electrical activity of neural pathways, coding for sound
Synapses transform what information to and from each other?
Electrical and chemical
How are BAEPs recorded?
Electrodes placed on the skull of the patient and sounds are played to the ear (electrical activity is recorded)
What is the term given to recording these potentials?
Electrophysiology
Why must synapses be able to increase (LTP) and decrease (LTD) their strength? (3)
Enables a dynamic range of synapse function Prevents saturation of synaptic responses Prevents loss of plasticity
Motion *is* encoded where?
Encoded after just a few synapses
What allows you to convert Short-term/Working Memory into Long-term Memory?
Encoding
Memory
Encoding, storage, retrieval of learned information
Surgical procedure removing the thrombus is called
Endarterectomy
The *sensory transduction* process is based on which special potential?
Endocochlear Potential of +80mV https://o.quizlet.com/V9GDHV-i8nAHrgOBX4VZcQ_m.jpg
[2] Induction
Endogenous (inducing) *Signalling Molecules* secreted by distinct embryonic cell classes or tissues (such as the primitive pit and notochord) which results in *spatial and temporal* gene expression in *adjacent* cells or tissue.
Leukocytes will always make contact with the which cells first?
Endothelial Cells
Color is created by utilizing which (2) properties of light?
Energy/intensity and frequency of vibration/wavelength
What are cell culture models?
Engineered or cancer cell lines that have gene knockouts/ins
First Pathway: GABA co-transmits with what and the pathway has which receptors? (all of which is lost in HD)
Enkephalin Cannabinoid and *Dopamine Receptors*
Braille: Training leads to
Enlargement of reading finger cortical representation. Takes days/week.
Increased exposure to an _____ environment during childhood leads to what?
Enriched environment, it becomes more likely that more neurons will retain these synapses after pruning occurs
What are phosphatases?
Enzymes that remove phosphate groups from proteins
Examples of disorders of movement (5)
Epilepsy, Polio, Parkinson's, Huntington's, MS
Types of Declarative Memory (2)
Episodic and Semantic
How can Germline Gene Therapy be used?
Eradication of genetic disease before baby is born
The middle ear is a cavity that communicates with the pharynx through the
Eustachian Tube (permits equalization of pressure on each side of the eardrum)
Left and Right fields are
Everything you can see on the left - left field Everything you can see on the right - right field
Do humans have a VNO?
Evidence of small, VNO like structure in adultnasal floor, not sure if functional
Chemical senses elicit what responses in humans?
Evoke very strong emotional responses
Flexion (withdrawal) Reflex
Evokes fast withdrawal of limb from a nociceptive stimulus https://o.quizlet.com/f0-ho-bh2yuy6SU82Zk0NA_m.jpg
Once we have a confirmed depressed animal model, what can we do (before giving them drugs)?
Examine pathophysiology of depression at cellular/moleuclar level
Glutamate excitotoxicity
Excessive release of glutamate -> Death of postsynaptic neurons
New neurons that form at the olfactory bulb are very _____. This means
Excitable, Will readily convert short term memory to storage of memory (long term)
Neurons at the developing age are super _____. This means
Excitable, they learn better when they are excitable (very high in teenage years)
The moving of the Organ of Corti will cause
Excitation and Inhibition of the Hair Cells, producing a receptor potential https://o.quizlet.com/R7sEkGJziFhjP2Az.vXFRw_m.png
Modality: Receptor Potential
Excitation leads to electrical response
Because microseizures are EEG *spikes*, we assume them to be
Excitatory Events
Ventriculomegaly
Expansion of the ventricles as a result of holes and diffuse white matter lesions
Why don't we have disease modifying drugs?
Expensive ($1bil) and time consuming (10 years from preclinical research → Approved drug)
Olfactory organ organised into Zones which express
Express *a particular subset of receptor genes* https://o.quizlet.com/e.1Q47xEua1RtKZXfKn3vQ_m.jpg
Aß42 forms what where?
Extracellular plaques
Muscle Spindles are in parallel with
Extrafusal Fibers
αMNs innervate
Extrafusal Muscle Fibres https://o.quizlet.com/caoarFRemNyXFf1vGVe9aQ_m.jpg
Conditioning: Motor skills
Eye blink conditioning (cerebellum) Sound and air shot at your eyes causing a blink Eventually, beep causes blink https://o.quizlet.com/Wk6z5DfjDE6xpl0aFcoo5g_m.jpg
Vision requires which (3) basic parts?
Eyes Optic connection to the brain Brain https://o.quizlet.com/gKf0zVcO.WY0aevE426oEA_m.jpg
Most common example of False Memory?
Eyewitness misidentification → leading cause of wrongful conviction
Gastrocnemius has mainly what fibers?
FF Type
When BMP4 is present alongside _____, what forms?
FGF (Fibroblast Growth Factor), posterior neuroectoderm forms (spinal cord)
Examples of Neurotrophic Factors (2)
FGF, BDNF (Brain Derived Neurotrophic Factor)
Delivering high frequency stimulation will
Facilitate excitability - LTP *like*
Patterned theta burst stimulation: Intermittent
Facilitates excitability (LTP-like) https://o.quizlet.com/J1VaHeQWEUYFSZ2x9G8dnA_m.png
Dementia
Failure of recent memory and intellectual abilities
Size of DSGC receptive fields and sensitive to which type of changes?
Fairly large, sensitive to small changes
What is (1) colour vision test?
Farnsworth Panel D-15 https://o.quizlet.com/wAHEUg-cpnEcYqubj5UrAg_m.jpg
Aδ (III) Fibers (speed and to where?)
Fast Pain to PSC (Discriminative)
Large Ganglion Cells process
Fast, transient impulse trains
What is another taste that may have its own specificity?
Fat https://farm6.staticflickr.com/5050/5383384526_19ae18883b_m.jpg
Conditioning: Emotion
Fear conditioning (amygdala) Associating sound with foot shocks for mice Eventually, sound causes mice to jump
Affective-Motivational Area
Fear, anxiety, painful experiences
What is the problem with these drugs?
Feeling better/therapeutical onset occurs weeks after/lags behind the serotonin/noradrenaline reuptake
Impaired oxygen delivery
Fetal hypoxia → Anaerobic metabolism and lactate production → Metabolic Acidosis
S/FF: # of axon terminals
Few/Many
Skin can have _____ or _____ fields
Fine or diffuse
What does stimulus intensity affect? (2)
Firing rate of neuron Number of neurons firing (like recruiting more myocytes for forceful contraction)
Treatment of acute ischaemic stroke: Treatment must be administered before irreversible damage has occurred, which is how many hours?
First few hours after insult
Sir John C Eccles (Nobel 1963). What did he do?
First person to investigate neurons (motor) with intracellular micro electrodes in 1950
Flexion (withdrawal) Reflex Effector
Flexor Muscles (flexor/fetal)
Aqueous Humor
Fluid filling space between lens an cornea https://o.quizlet.com/qYBY-zH.9Pzvw9N6b-jTlA_m.png
Extrafusal Muscle Fibres are responsible for
Force generation
Motor System Components (6)
Forebrain, brainstem, spinal cord and all muscles (~750) with inputs from basal nuclei and cerebellum https://o.quizlet.com/2C0LsLu2AceMRafBVAL7QA_m.png
What happens to tau and what does it do?
Forms fibrils inside cells (neurofibrillary tangles) and this ccauses injury to the cell
What are the (2) major processes during sound transduction?
Forward and Reverse Transduction
What forms at the anterior end of the neural tube? (2 names)
Fourth Germ Layer or Neural Crest Cells
What type of receptors (physiological) are thermoreceptors?
Free Nerve Endings
(5) receptors in skin
Free Nerve Endings/Tactile Disc/Merkel Cells Root Hair Plexus Meissner's/Tactile Corpuscles Lamellated (Pacinian) Corpuscles Ruffini Corpuscle (Fred Rooted Miss Tracy's Large Peachy Rearside)
Possible Pathophysiology of neuronal death in Parkinson's disease? (4)
Free radical Neurotoxicity Excitotoxicity Mitochondrial dysfunction Loss of neurotrophic support
Ultrasounds
Frequencies above 20,000 Hz
Infrasounds
Frequencies below 20 Hz
(2) ways to ↑muscle force?
Frequency Encoding - ↑frequency of APs @ individual αMNs Recruitment - ↑recruitment of additional Motor Units
The Primary/Secondary Auditory Cortices are tuned to (2)
Frequency and Intensity https://o.quizlet.com/xjQwb2FsOZBlJxMf7l6.SA_m.jpg
Cognitive decline spectrum
From normal memory loss → dementia and Alzheimer's Disease
What switch in migration occurs for the Rostral Migratory Stream to exist?
From the Subventricular zone (cells stop migrating *radially*) and start going *tangentially* towards the olfactory bulb
There is extensive feedback in the auditory pathways. Which example did he give?
From the Superior Olivary Complex -> OHCs, protection from sudden loud sounds (reduce sensitivity of the cochlea)
What does insertion of more AMPA receptors require? (Literally)
Fusion of an intracellular membrane compartment with the postsynaptic membrane https://o.quizlet.com/aegUTlKpNYN20y.5Np-TVw_m.png
Starburst Amacrine Cells release
GABA and ACh
CB1R is present in __(NT)___ and __(NT)__ synapses
GABA and Glutamate synapses
Give (2) examples of inhibitory neurotransmitters?
GABA, Glycine
What is happening now?
GDNF infusion restarting now
Which protein stains Astrocytes?
GFAP - Glial Fibrillary Acidic Protein https://o.quizlet.com/peLKnZIs0WaDYH1RCDVurg_m.png
What type of receptors are Cannabinoid Receptors?
GPCR
Each different representation is carried by a separate class of
Gaglion Cell
Bipolar Cells synapse directly onto
Ganglion Cells
What is Cross Innervation?
Gastrocnemius became slow like and soleus became fast like when αMNs switched https://o.quizlet.com/dlb-GIMdIwr2bLQmpjWHpg_m.jpg
The genetic aetiology (i.e. polyglutamines) of HD is an example of
Gene Dosing
Ischemia can be of (2) types
Generalised - whole body Specific - Specific tissues/organs
Differences in paternal or maternal inheritance of CAG repeats is called
Genetic Anticipation
What are (2) causes of Polymicrogyria?
Genetic or in utero infection
Cellular Tropism: Use different serotypes to? (2)
Get different expression patterns (e.g. focused or diffuse) Infect different cell types
Why is classification based on appearance better than being based on *functional markers*?
Gets too complicated
GABA Agonists
Give GABA to ↓hyperkinesia
How can we block the protective response?
Give adenosine blocker (inhibitory neurotransmitter) https://o.quizlet.com/YmOY59LSJqNsp74stlRdTA_m.png
What is the advantage of this?
Gives us opportunity to treat before post injury damage
Which CNS/PNS cell type is the most numerous is most mammalian species?
Glial Cells
Schwann Cells and Oligodendrocytes are ____ cells that form a
Glial cells that form a rigid substance
Astrocytes are the major origin of which aggressive form of brain tumor?
Glialblastoma
Axons of sensory neurons specific to a particular odorant converge to form a ____ in the olfactory bulb
Glomerulus https://o.quizlet.com/Alkh4.hIj43O5BNakIo61w_m.jpg
Which nerves take gustatory sensations from the back of the tongue and the epiglottis?
Glossopharyngeal (9) and Vagus (10), also to the Nucleus of the solitary tract (Gustatory nucleus) https://o.quizlet.com/rh4lx8IaEhdG73.kKvTQug_m.jpg
What does the BBB allow to pass easily?
Glucose
Pathophysiology of ischaemic stroke: Brain physiology
Glucose primary energy source Receives 20% of CO
(2) Production of ATP (energy) under anaerobic conditions
Glucose → 2ATP + lactate
A major excitatory neurotransmitter is?
Glutamate
Pax6, Emx2, Dlx2 tell the cells to become responsive to and produce a lot of (1)
Glutamate
Memantine
Glutamate Antagonist, prevents excitotoxicity
How can we stop seizures, nevertheless?
Glutamate antagonists - minimize excitatory effects of glutamate
What is the main primary excitatory transmitter in the CNS?
Glutamate https://o.quizlet.com/i/mrStyH5yQUbIeO11JXuEIw_m.jpg
Short Term Memory involves
Glutamate → NMDA activation → ↑Ca → CaMKII activation → AMPA receptor phosphorylation + AMPA receptor insertion → ↑ AMPA current https://o.quizlet.com/l-.L-xJ-KKpheVEUOAZixA_m.jpg
LTP is observed at what type of synapses?
Glutamatergic
How do you speed things up?
Go straight from skin cells → mature neuron through a different set of genes (Brn2 / Ascl2 / Myt1l) - takes a week
What are (2) proprioceptors?
Golgi Tendon Organ Neuromuscular Spindle
Reverse (Inverse) Myotatic Reflex utilises which physiological receptor?
Golgi Tendon Organ https://o.quizlet.com/3oG4xcZBQNKvtyqosXtqeQ_m.jpg
Reverse (Inverse) Myotatic Reflex Receptors
Golgi Tendon Organs monitoring tension during contraction
The BBB regulates the entry of other proteins and molecules which are
Gradient or Receptor mediated
At term Perinatal Brain Injury is predominantly
Grey Matter Injury
What are the two types of matter in the nervous system?
Grey and White
Myotatic Reflex Afferents
Group Ia (Small/fast stretch) Group II (Sustained stretch)
Dementia isn't a disease, it's a
Group of symptoms
What is the progression of aneurysms?
Grow in size, cause complication only when ruptured
Dendritic growth, like the axon, occurs at a
Growth Cone
Growth of axons occurs at a
Growth Cone
Induction occurs through secreted
Growth Factors
In the development of the CNS, why are growth factors important?
Growth factors help to aid growth or restrict areas of the CNS for proper folding, turning, twisting etc https://o.quizlet.com/7HONHcY.1IiK3mxoruK5Fg_m.png
Name for taste cortex?
Gustatory Cortex
Taste buds synapse with what at which end?
Gustatory afferent axons at basal end
Anterograde Amnesia Patients (2)
HM and RB
RB
Had cardiac issues → Ischemic episode during surgery → loss of neurons in the CA1 region of hippocampus https://o.quizlet.com/5KgduaO9fFBuDcbzKyOSdw_m.jpg
What does the electro-chemical K+ gradient account for?
Hair cell depolarisation
By 16, how many of the original synapses remain?
Half
What happens to preterm baby at 23 weeks, if we let it grow until 40 weeks and compare with a normal 40 week birth?
Has a smaller brain and less cortical folding compared to at term counterpart (not always) https://o.quizlet.com/5lpmsT9zb2X7IMOraWmfGw_m.png
Outer Hair Cells OHC (function - how much amplification - and shape)
Have a role in cochlear amplification - amplify sound by about 50-60 dB, Cylindrical Shape
What have animals done in regards to their sensory systems?
Have adapted their sensory systems to their environment
Why is giving mother corticosteroids to tackle foetus RDS bad?
Have negative affects on baby
Common: General Freatures
Have sensory receptors Have >1 Neurons (1˚, 2˚ etc)
Where can we derive cell cultures?
HeLa, other cancer cells
Noramally, CB2R expression is low in
Healthy Brain Tissue vasculature
What is a treatment of loss of OHCs? But?
Hearing Aids to restore the intensity of sound, but cannot restore the speech discrimination (still have problem understanding speech)
The Y axis represents
Hearing Loss in dB
Which centers overlap at the Auditory Cortex? (2)
Hearing, Speech and Language Centers
3. What can cause reduced systemic perfusion pressure? (2)
Heart failure (Infarction) Hemorrhage or dehydration
VR-1 receptor responds to? (3) (Temp and 2 chemical)
Heat Acidic Conditions Capsaicin (chilli)
Extrareceptors
Help to guide motor movements
Glia have very important _____ function and are the brain _____ _____ cells
Helper, Brain resident immune
GDNF does what?
Helps dopaminergic neurons to survive
Sufferers with damage to Primary Somatosensory Cortex suffer?
Hemineglect
The brain can be divided into left and right
Hemispheres
Stage 4: What part of the tectorial membrane will come into contact with the IHC stereocilia and cause subsequent IHC depolarisation?
Hensen's Stripe https://o.quizlet.com/-jsmlETcajY5W05QGpBVJg_m.png
Opponent Colour Theory: First proposed by
Hering in 1872
Spina Bifida Occulta
Hidden/ *mildest* form. The outer part of some of the vertebrae is *not completely closed*. Sometimes *hair* on skin at the site of the lesion. *Asymptomatic*.
Age Related Hearing Loss starts at which frequency region?
High Frequency region https://o.quizlet.com/po-4s68yyl-7iKnGV1PO2w_m.jpg
How is the intensity of sound distributed when the high frequency sound comes from the *right*?
High for the right ear, casts a *complete sound shadow* on the left ear (lower intensity for left ear) - cues auditory system that sound is from right https://o.quizlet.com/KykiHgdzh7YQKtzRNYoT8A_m.png
In which (2) ways can we elicit a large calcium influx to evoke LTP?
High frequency (tetanic) presynaptic stimulation *or* Low frequency presynaptic stimulation plus significant postsynaptic depolarisation (pairing)
Knock-in Huntington's Mice: Normally (i.e. no HD)
High frequency stimulation → LTP induced → baseline potential changes → larger amplitude in response to neurotransmitter
In diseases such as Alzheimer's and Parkinson's, what blocks the removal of PSA?
High levels of insulin/glucose
S/FF: Abundance in average muscle
High/Low
S/FF: Capillaries
High/Low
S/FF: Mitochondria
High/Low
S/FF: Myoglobin
High/Low
What happens to high/low frequency sound as it travels through the cochlea?
High: It dissipates quickly Low: Travels much further, to cause displacement of basilar membrane closer to the apex
Cones allow us to detect
Higher levels of light (higher threshold to light) - day vision, colour vision
Somatosensory Association Cortex is for what kind of processing
Higher order processing (e.g. object recognition) Giving meaning/making associations with sensation
Ageing Population means
Higher proportion of elderly in population at a given time
What are synapses?
Highly specialised sites of the neuron (neuronal contact)
Other name for Rhombencephalon
Hindbrain
What have these studies used in vitro?
Hippocampal slice preparation
What was invented in the 1960s?
Hippocampal slice preparation
Cells in which other (2) structures of the brain have some regenerative abilities?
Hippocampus (memories) and Cerebellum (coordination)
Hippocampal slice preparation
Hippocampus can be easily be dissected from the brain, sliced like a loaf of bread, and kept alive in *oxygenated artificial cerebrospinal fluid* https://o.quizlet.com/pjTJO0Z4M8OuQoHXGPK7pg_m.png
Which structure in the brain is important in Declarative (explicit) memory?
Hippocampus https://o.quizlet.com/BOmnjtdNzUR9KsCRMsB2lQ_m.png
Where do we see neuronal loss/atrophy? (3)
Hippocampus, Frontal or Temporal Cortex
MRI allows us to detect (3)
Holes (Cavitary) Diffuse white matter lesions Ventriculomegaly https://o.quizlet.com/Ugwu1tUrq-jc1pobV9eZZw_m.png
Myotatic Reflex Effectors
Homonymous (same) Muscle (Extrafusal only)
Reverse (Inverse) Myotatic Reflex Effectors
Homonymous Muscle
Sound Localisation (where sound is coming from) can occur in which planes? How many ears are needed for these? (2)
Horizontal (need both ears) and Vertical (need only 1 ear)
3. Posterior circulation infarct (POCI): Other clinical features may include:
Horner's syndrome (drooping eyes) Nystagmus (REM), vertigo (dizzy), vomiting Coma Choreoathetosis, hemiballismus (movement disorders)
LTP can decay over
Hours
Adaptation of mechanoreceptors?
How quickly a receptor returns to normal state
Factors: Spatial Frequency
How rapid the stimulus changes across space (something that moves)
Expression
How synapse strength is increased
Maintenance
How the increased synapse strength is maintained
The branching of DS Ganglion Cells seems to be related to
How they sense orientation
Voluntary temperature responses?
Huddling Physical activity (hand rubbing) Shelter next to heat
All colours can be fully specified in terms of which (3) characteristics? (Munsell Colour System)
Hue, tone and saturation https://o.quizlet.com/1TrKD0XGuN5GUApIBYc3cw_m.jpg
What decreases with age? (2)
Human brain weight (loss of neurons) Synapse counts in cortex = ↓connectivity between neurons
Why are animal models better than human models?
Humans can have multiple pathologies (↑BP, diabetes) and vary in genetics, age etc. Lab animals are consistent, healthy, specific weight/age (i.e. controlled variables for an experiment) which give reproducible results
How many olfactory receptor cells in Humans, rats and dogs?
Humans: 12 million Rats: 15 million Dogs: 1 billion https://o.quizlet.com/KTtXuh2T4FC.rSBpQEG.uQ_m.png
What do we observe in the secondary phase? (4)
Hyperperfusion Secondary Oxidative Metabolism Failure Seizures Oedema https://o.quizlet.com/NAGHYy7zyceKB2BjH.i36Q_m.png
What does Cl- influx do to the postsynaptic membrane potential?
Hyperpolarises it https://o.quizlet.com/JXdKKKvIS4-MC37KU7om9w_m.png
Causes of Intracerebral Haemorrhage (ICH) (3)
Hypertension Cerebral Amyloid Angiopathy (CAA) Other causes
Retina Projection: Suprachiasmatic Nucleus
Hypothalamus - Which regulate the circadian rhythms
Causes of Perinatal Brain Injury (4)
Hypoxia-ischemia (main cause) Infection Accident/trauma (maternal) Teratogens
Opponent Colour Theory: What does the theory mean by responding in an antagonist way?
I.e. Either red or green is perceived and never greenish-red (i.e. some other colour forms) https://o.quizlet.com/4icxgqnokKrCMs6JTtjqNg_m.png
What part of the blastocyst forms the baby?
ICM (Inner Cell Mass)
These cells resemble what without the problem of what?
ICM of blastocyst, without ethical issues of using embryonic stem cells
Forward Transduction
IHC Stereocilia - hair cells convert mechanical stimuli into electrical responses
Afferent Fibers innervate mainly the _____ (type of cell). What is the function of these cells?
IHCs - They vary in frequency response and spontaneous firing rate, providing frequency and intensity coding
What is the name given to the chloride ion current flow into the postsynaptic cell?
IPSC - Inhibitory Postsynaptic Current
What is the name given to the resulting transient hyperpolarisation of the resting membrane potential?
IPSP - Inhibitory Postsynaptic Potential
Intrafusal Fibre belly is innervated by
Ia Afferent Fibres
Myotatic Reflex Synaptic Relays
Ia afferents → (Glutamate) → αMNs in spinal cord segment
Which fibers do Proprioceptors use?
Ia and Ib fibers (fast)
Reverse (Inverse) Myotatic Reflex Afferents
Ib Fibers
Reverse (Inverse) Myotatic Reflex Synaptic Relay
Ib afferents → (Glutamate) → Ib interneurons → (Glycine - Inhibit) → αMNs controlling homonymous muscles
How are chemical senses (olfactory and gustatation) evolutionarily beneficial? (3)
Identify food (bitter to spit out something that is poisonous), noxious substances, suitability of mate
How are disease models used specifically? (3)
Identify treatment targets See how effective treatments are Establish proof of treatment/theory behind treatment before clinical trials
How is LTP prevented with the use of blockers?
If blockers bind NMDA receptors during LTP induction (not afterwards) Red: What happens if the blocker is introduced during induction Black: What happens if the blocker is introduced after induction https://o.quizlet.com/LfyBX7wBk-V3..FRsQcDvg_m.png
Motor Disorders can be Motor or Sensory. What does this mean?
If sensory is damaged, can affect motor function
Modality Dependent Learning
If you are hungry, and you experience things with food, you are more likely to remember that
Why is myelination beneficial? (Insulation)
If you don't have the insulation of long distance neurons, the action potential could propagate to areas other than intended, so myelin helps direct the signal
Why is myelination beneficial? (Motor Neuron)
If you have long axons (motor), myelination makes it easier (less effort, energy required) to send a potential to a far away location
What is the first component of the visual pathway?
Image processing in the retina
The somatosensory system gives us information about the
Immediate Environment
Consolidation can be from (2) to LTM
Immediate Memory or STM → LTM
Types of memory based on Duration of retention (3)
Immediate/Sensory memory Short-term/Working Memory Long-term Memory
Microglial Cells are what type of cells
Immune Cells
CB2 widely expressed in the
Immune System
CB2 Receptor
Immune System, poorly expressed in CNS
In diseased state, where is CB2 expressed?
Immune cells and on the brain vasculature
What type of classification of human microglial subsets is poor?
Immunological
Knock-in Huntington's Mice: Pathology/Experiment
Impaired LTP → could not maintain LTP (*EPSP declines over time*)
The Acidosis causes
Impaired cardiovascular system → Reduced brain blood flow and oxygen → Hypoxia-ischemia → Brain Injury
Umbilical cord occlusion leads to (2)
Impaired oxygen delivery Impaired waste removal
Forgetting - Why important?
Important that we don't retain everything (immediate, STM etc.)
What is Multisensory integration?
Improves detection, localisation, attention Visual and auditory systems have interactions I.e. When they see *and* hear the dog barking, the stimuli are small but the output is large due to combination of the systems When the dog is close, and both auditory and visual output is large, the additive output is not big anymore https://o.quizlet.com/o8c9mJsmWvqICUdXfS5EqQ_m.png
Antidepressants
Improves mental wellbeing
Touch
Impulses propagate through spine and up to cortical regions https://o.quizlet.com/sxQa.LkpKokWKuMt2x6oFQ_m.png
The Outer Hair Cells are arranged in how many rows?
In 3-5 rows
What are (2) mechanisms of Gene Delivery?
In Vivo and Ex Vivo
Interneurons
In contrast to sensory and motor neurons that synapse with the skin or muscle at one end and neurons at the other, interneurons synapse with neurons at both ends (Dendrites and axon)
Creatine Monohydrate
In meat, for muscle recovery
The stationary stimulus appears to move in which direction?
In the opposite direction to the original (physically moving) stimulus
Motion is not encoded where?
In the photoreceptor layers of the visual system
Ischemia
Inadequate blood supply
Abnormal Huntingtin (Htt) accumulates to form?
Inclusion Bodies
What are the abnormal aggregates of protein that develop inside nerve cells in Parkinson's disease?
Inclusion Bodies or Lewy Bodies
What leads to LTD and LTP in terms of phosphatase and kinase activity?
Increase in Phosphatase activity - LTD Increase in Kinase activity - LTP
What happens to synapses?
Increase in size, perforate or split to form additional spine heads https://o.quizlet.com/ee6wV-fNnYTnzRk6C0KM8g_m.png
What is Hypothesis 1?
Increase in transmitter release
What are (4) possible LTP expression mechanisms (things that contribute to increase in synapse strength)?
Increase in... 1. Transmitter release (more glutamate) 2. The number of postsynaptic receptors (AMPA/NMDA) 3. The conductance of existing receptors 4. The number of synapses
Changing in strength means either increase or decrease in
Increase or decrease in synapse strength (the amplitude of the postsynaptic currents)
What is Hypothesis 2?
Increased AMPA Receptor number https://o.quizlet.com/AJLJUyK3MW7hjrPa1FxZtw_m.png
What is Hypothesis 4?
Increased Synapse Number
What if we have mutations in the APP protein?
Increased chances of production of Aß42 https://o.quizlet.com/dXlJ4tHJDQBIy7E6Oqkwpg_m.jpg
What is Hypothesis 3?
Increased pre-existing postsynaptic receptor conductance
Rigidity
Increased resistance to passive movement of limbs
What does myelination do?
Increases the speed and specificity of neural conduction
What was the result?
Incredible improvements in patient symptoms (PD) and went to Phase 2 Clinical trials as a result (one patient post mortem brain showed sprouting of new neurons)
What (2) Objective recordings can we make?
Individual Unitary Potentials Compound Potentials
What can CaMKII injection into a postsynaptic cell do?
Induce LTP (is sufficient to do so) https://o.quizlet.com/irRkn9sQJWvxfyKhQ5sh7w_m.png
What are (2) derivatives of iPSCs?
Induced Neural Stem Cells (iNSC) Induced Neural Precursor Cells (iNPC)
What are these cells called?
Induced Pluripotent Stem Cells (iPSC)
The notochord is responsible for what process during development?
Induction
Endocytosis of receptors is a critical step in
Induction of LTD
What are the (3) phases of LTP? (What are axis?)
Induction, Expression and Maintenance https://o.quizlet.com/R7MjliJ7r7KMd-pjZyOeTA_m.png
Retrovirus (RV)
Infect dividing cells only (i.e. only stem cells and not neurons) Can't control where gene is inserted (e.g. if near oncogene → cause cancer)
Causes (3)
Infections Genetic Environmental Toxins
Adenovirus (Ad)
Infects neurons well
Microglial Cells show up in the presence of
Inflammation
What is produced by astrocytes that may be detrimental to neuronal cell health?
Inflammatory Mediators
In the shunting inhibition, the inflow of negative ions negates the
Inflow of positive ions
The AP at the *presynaptic* membrane results in the
Influx of Ca2+ ions through voltage gated Ca channels concentrated around the terminal
Visual Pathway
Information received from the photoreceptors passed to specialised cells. E.g. for colour, contrast, shape perception https://o.quizlet.com/sqE4-uga.WdqpC1JytN2mg_m.jpg
How do you get HD?
Inherited
What are three types of gene therapy for PD?
Inhibition therapy Neurotransmitter Enzymes Neuroprotective agents (Neurotrophic Factor GDNF)
What type of synaptic transmission do Interneurons mediate?
Inhibitory
Lamellated Corpuscles
Initial contact/high frequency vibration
Tactile Corpuscles
Initial contact/low frequency vibration
Ex Vivo Gene Delivery
Inject viral vector into donor cells then implant them into host
In Vivo Gene Delivery
Inject viral vector into host
∆ cortical representation can occur in response to (2)
Injury or Experience
When is dementia irreversible?
Injury or disease
In-utero MRI allowed us to discover that
Injury/injurious events can occur well before birth
Astrocytes have which immunological function?
Innate Immunity - resident brain innate immune cells
What (4) things make up the BBB?
Inner endothelial layer Basement membrane A continuous layer of pericytes SMCs (sometimes) https://o.quizlet.com/HqpGdue90MSMJB49PqteGw_m.png
Number of muscle fibres innervated by individual MNs is called the
Innervation Ratio
AMPA and NMDA receptors are
Inotropic
Neurotransmitters
Insert gene into striatum that codes for *enzymes involved in the endogenous biosynthesis of dopamine*, to indirectly increase dopamine
Inhibition Therapy
Insert gene into subthalamic nucleus (6OHDA rats) that expresses GAD - precursor for GABA. GABA is inhibitory so dampens the overexcitability imbalance of DA/ACh at the striatum.
Neuroprotection
Insert gene that encodes for synthesis of a neuroprotective factor such as GDNF (Glial-Derived Neurotrophic Factor) over years
How does AMPA receptor insertion and removal represent LTP and LTD?
Insertion is LTP and removal is LTD - they are constantly being recycled https://o.quizlet.com/0rAwVzN3koAM1GErFNQcgQ_m.png
Which (2) factors likely underlie LTP expression?
Insertion of new AMPA receptors AND an increase in the conductance of existing AMPA receptors
How could AMPA receptor number increase?
Insertion of receptors into the postsynaptic membrane from an intracellular pool
Proprioceptors
Inside body, in muscles/joints provide feedback information
Anterior Spinocerebellar Tract
Integrates proprioceptive information with *Descending inputs*
Declarative Memory Consolidation depends on (2)
Integrity of the hippocampus Hippocampal connections to the *mammillary body* and *dorsal thalamus* https://o.quizlet.com/AwOByCrXV16i941vI3VgLg_m.jpg
Frontal Association Cortex function? (4)
Intelligence, behaviour, mood, personality
Aδ Mechanosensitive Nocioreceptors
Intense Mechanical Stimuli
Aδ Mechanothermal Nocioreceptors
Intense Mechanical and Thermal Stimuli
What are the (2) things we detect in sight?
Intensity (amount of light) and Wavelength (colours)
Which (2) components of sound contribute to Noise Induced Hearing Loss?
Intensity of noise and duration of exposure to noise (Intensity * duration = sound dosage)
Perception of sound - (3) features of sound waves (think physics)
Intensity, pitch and direction
What other cue do we rely on to localise high frequency sound?
Interaural Intensity Difference
What is the delay called between ears?
Interaural Sound Delay
What else can Microglial Cells secrete? (3)
Interleukins, Growth Factors and Support Factors
What evidence shows that apoptotic pathways are essentially brewing in the latent phase?
Intermediates such as Bax, CytC and Caspase-3 increase https://o.quizlet.com/3OsTTuzZ66PObjG0oq7bSQ_m.png
The Globus Pallidus and the Substantia Nigra can be broken down into
Internal & External Globus Pallidus and Pars Compacta & *Pars Reticulate*
1. Anterior circulation
Internal carotid artery → (1) middle and (2) anterior cerebral arteries, and (3) Ophthalmic artery (1) Supplies lateral hemisphere (2) Supplies anterior three-quarters of medial hemisphere. (3) Supplies optic nerve and retina
Perception (L1)
Interpretation modified by experience
Peripheral Nerve Somatosensory Injury Types? (3)
Intra-nerve damage Mono-neuropathy Poly-neuropathy
Tau is assocated with
Intracellular Microtubules
Muscle Spindles contain multiple
Intrafusal Fibres https://o.quizlet.com/i9DPkDXlFA4P-CI.y0Hi6w_m.jpg
𝛾 Motor Neurons innervate
Intrafusal Muscle Fibres in Muscle Spindles
Motion detection is studied in
Invertebrates and low vertebrates
Non-Declarative memory
Involves skills and associations, at the unconscious level (i.e. guitar)
Brown-Squared Syndrome (hemisection)
Ipsilateral loss of proprioception, vibration, light touch Contralateral loss of crude touch, pressure, pain (dissociated sensory loss) https://o.quizlet.com/HMDt-36OziJCro4JcYvetQ_m.jpg
Noise
Irregular sound with no particular frequency https://o.quizlet.com/P4IQPGmiIoZYgtN18Q7qXw_m.jpg
Eventually ischaemia leads to
Irreversible cellular damage
Tegmentum
Is the path of the *anterolateral* (spinothalamic) system (pain and temperature).
When blood flow to part of the brain is reduced, survival of the affected brain tissue depends on
Ischaemia severity Ischaemia duration Availability of collateral blood supply
(3) types of stroke
Ischaemic stroke (Infarction) Intracerebral haemorrhage (ICH) Subarachnoid haemorrhage (SAH)
What is another colour vision test?
Ishihara Test https://o.quizlet.com/jTwlgyKBQ91PPQCapF7ULg_m.jpg
How severe can Lissencephaly be?
It can be global (whole cerebral cortex) or regional areas of smoothness
What happens if you electrically stimulate presynaptic axons?
It induces AP firing in that presynaptic neuron, leading to glutamate release from the presynaptic terminal
What is special about the NMDA receptor?
It is ligand gated AND voltage gated
What happens to the vesicle after NT release?
It is recycled by endocytosis, taking along with it NT for recycling also
How does myelination affect the size of the brain?
It is responsible for quite a bit of enlargement of the brain
How do we activate an NMDA receptor?
It requires glutamate AND a depolarised postsynaptic membrane potential (to unbind the Mg) https://o.quizlet.com/C2.0WVGvuZdY9G2Tj1y81Q_m.png
So what can we say about Hypothesis 1 (Increase in transmitter release)?
It's crap (fail)
What part of the stapes is inserted where?
Its footplate, into the oval window of the cochlea
Vitreous Humour
Jelly like tissue filling the eyeball behind the lens https://o.quizlet.com/0wkq3K162Ywi7z5A5gxDdg_m.jpg
How does this compare with non-depressed controls?
Just keep swimming, just keep swimming, just keep swimming, swimming https://farm8.staticflickr.com/7108/7415156290_8ac1ec3dbc_m.jpg
Stage 2: What is located at the tips of the stereocilia?
K+ *M*echano-*E*lectrical *T*ransduction Channels (M.E.T channels) https://o.quizlet.com/Ccp1LPhGHZt6279d-eG1LA_m.jpg
What is the role of 𝛾 Motor Neurons innervating the intrafusal fibers (non-belly sections)?
Keep intrafusal fibres taut/at appropriate length to they remain active during muscle shortening
How does the anterior neural tube give rise to the adrenal glands?
Kidneys are in the chest in development, they descend down when we are born
What are phosphatases the exact opposites of?
Kinases that are activated by high calcium levels during LTP induction
Levodopa (L-Dopa) and Dopa decarboxylase inhibitors
L-Dopa converted to Dopamine by Dopa Decarboxylase (everywhere in the body) L-Dopa converted into dopamine during digestion - nausea and vomiting (peripheral side effects) L-Dopa given with Dopa decarboxylase inhibitors (they can't cross BBB) so L-Dopa remains as L-Dopa in periphery but crosses BBB by itself and is converted into dopamine there
A small calcium influx results in
LTD
What is different about LTD induction compared to LTP?
LTD requires more time (15 mins) compared to LTP (1 min)
A large calcium influx results in
LTP
Knock-in Huntington's Mice: Result
LTP ability maintained *i.e. increased ESPS)* even in these induced Huntington's mice
Why do we say (i.e.) LTP *like* for human trials?
LTP and LTD are reserved for animals
What happens if induction is blocked?
LTP cannot be expressed or maintained
What happens if membrane fusion is blocked?
LTP expression is prevented
Supportive Evidence: What can be induced with brief trains of stimulation in vivo?
LTP/LTD
Find Engram: Step 2 - Label?
Label cells of engram via viral transfection
What is the pathophysiology of Polymicrogyria?
Lack of cell death or abnormal cell migration
Symptoms of Polymicrogyria?
Lack of coordination and failure to thrive at school
What is the capacity of Immediate/Sensory memory?
Large
What are the (2) types of ganglion cells?
Large Ganglion Cells and Small Bushy Ganglion Cells
Type I spiral ganglion neurons (Size and myelination)
Large and Meylinated
Herpes Simplex Virus (HSV)
Large so can fit ↑genetic material
1. Arterial disease.
Larger Artery - Atherosclerosis Small artery - Lipohyalinosis
Myelination is early or late in development?
Late
Age Related Hearing Loss: Average onset?
Late 40s
Cerebral Cooling must begin in which phase to have effect?
Latent Phase
Which tract takes nociceptive information?
Lateral Spinothalamic Tract
Which tract takes temperature information?
Lateral Spinothalamic Tract (Non-Discriminative)
Retina
Layer at back of eyeball, contains light sensitive cells https://o.quizlet.com/i/yo54Z51mD1KcTgx2hELYcg_m.jpg
Declarative Memory Consolidation
Learning Facts
Although these studies have given us great knowledge about the function and molecules involved with LTP/LTD, there is no direct relationshi with
Learning and memory (the behavioural manifestation of the physiology)
Semantic Declarative Memory
Learning facts, for tests or birthdays
Supportive Evidence: Saturation of LTP can block
Learning, although this is controversial as there *may* be a physiological limit to memory?
Subarachnoid haemorrhage (SAH)
Least common, <5% Younger patients Bleeding into subarachnoid space - aneurysm
Lecture 1 - Huntington's
Lecture 1 - Huntington's
Lecture 2 - Parkinson's
Lecture 2 - Parkinson's
Lecture 3
Lecture 3
Lecture 3/4
Lecture 3/4
Lecture 4
Lecture 4
Lecture 4 Alzheimer's 2
Lecture 4 Alzheimer's 2
Lecture 5 Stroke
Lecture 5 Stroke
*Total Visual Field* is the sum of the
Left and Right hemifields
[Diagram] Layers of the cortex
Left: Anatomical Order Right: Developmental Order https://o.quizlet.com/XfIZhWnTSW-kVKQfZCLcQA_m.png
What does fewer AMPA receptors in the synaptic membrane mean?
Less current flow in response to transmitter release, and a weaker synapse
At *high* concentrations of stimulus (specific taste) most papillae are
Less selective
Deuteranopia
Less sensitive to green https://o.quizlet.com/ll0oJenDFl960tDARy2ZVg_m.jpg
Protanopia
Less sensitive to red https://o.quizlet.com/OMa2EYfbpXldXrSl5qL9UA_m.jpg
Endothelial CAM →
Leukocyte CAM
Treatments (5):
Levodopa (L-Dopa) and Dopa decarboxylase inhibitors Dopamine agonists Anticholinergic agents COMT inhibitors Surgical treatment
What type of gated receptors receive GABA and glycine on postsynaptic membranes? These receptors/channels are permeable to?
Ligand gated, permeable to Cl-
Free Nerve Endings/Tactile Disc/Merkel Cells
Light Contact
Which stimuli can end organs respond to? (5)
Light, heat, sound, movement, chemicals
CP Symptoms (6)
Limb Weakness Abnormal/No walking Limb Contractures/Spine Curvature Swallowing/Feeding Problems Learning Disabilities Social Alienation
In AD there is a diffuse loss of neurons in (5)
Limbic structures (memory, emotion and language) Hippocampus Amygdala and associated cortices Some brainstem nuclei Basal Forebrain
Problems with Viral Vectors (6)
Limit to insertable *DNA size* Can cause *cytotoxicity* Can elicit *immune response* *Cellular tropism can be bad* - targeting a cell type different to the one you want to target *Stable gene expression* - sometimes viral vectors do not integrate into host DNA and just float in cytoplasm (expressed) for a bit then bugger off *Imperfect regulation systems* - e.g. add tet to tet-on and the promoter does not actually turn on
What is the stereocilia arrangement in the IHCs?
Linear https://o.quizlet.com/QExAlMKhO8sLBkC0WNcowg_m.jpg
Cannabinoids are
Lipophilic
S/FF: Fatigue
Little/Rapid
Receptors may be _____ to give
Localised to give *higher definition* (eg fovea of retina, has high density and small receptive field) (Fine resolution for fingertips, but not for thighs for example)
Axons have specific targets that are located
Located enormous distances away
Low frequency stereocilia
Long
Studies have found that LTP could last
Long enough to underlie the storage and retention of memories
Increases in size and number of synapses are perhaps more for _____. Why?
Long term modification, as changes in spine structure take many *minutes to hours* to manifest
In LTD induction, AMPA receptors are activated over a
Long time period (5-15 mins) to induce weak depolarization
L-Cones, maximum sensitivity to
Long-wavelength sensitive, Red, 565nm https://farm4.staticflickr.com/3568/3306122583_3cc61e7d6e_m.jpg
What is happening when we look to the left?
Looking at our left field, all information going to right visual cortex of the brain
What is happening when we look to the right?
Looking at our right field, all information going to left visual cortex of the brain
First Pathway to Degenerate
Loss of Striato-pallidal (GPe) Neurons
Third Pathway to Degenerate
Loss of Striato-pallidal (GPi) Neurons
Anterograde Amnesia
Loss of ability to create new memories after injury https://o.quizlet.com/if5H0lT6G.42SDp-tvzQ2g_m.png
Permanent Hearing Loss - Loss of (2)
Loss of both Sensory Hair Cells and Auditory Neurons
Retrograde Amnesia
Loss of memories acquired prior to injury https://o.quizlet.com/CdIdzRbu1wclseu3CThoHA_m.png
Central Cord Syndrome
Loss of proprioception, vibration Motor impairment in arms (legs spared due to more external location) https://o.quizlet.com/YRSnHd2BooOUpu9ViZN3mg_m.jpg
Posterior Cord Syndrome
Loss of proprioception/discriminative touch Crude touch/pain remains intact https://o.quizlet.com/PbT7pVtVihwCUAdT5-jjIg_m.jpg
Spinal Cord Somatosensory Injury symptoms?
Loss of sensory function below spinal segment
The principal of Interaural Time Delay works well for
Low Frequency Sound https://o.quizlet.com/e-EfyZeK7JaywAdXFsVGNw_m.jpg
The Attenuation Reflex works better with which frequency sounds?
Low frequency sounds
Pairing (2)
Low frequency stimulation (1 Hz) of *presynaptic axons*, AND *postsynaptic depolarisation* by aritificial current injection for 1 minute
How can we elicit a small calcium influx to evoke LTD?
Low frequency stimulation of the presynaptic cell. Results in a weak depolarisation of the postsynaptic cell
S/FF: Glycogen
Low/High
Spinal Border Cells Integrate information from (3)
Lower limb Descending input Flexor reflex arcs
CSF Scanning
Lumbar Puncture/Spinal Tap Low CSF Aß42 in AD High CSF phosphorylated tau in AD
How do lung development problems cause Perinatal Brain Injury?
Lung development problems, poor surfactant, postnatal apnea → ↓BP → ↓blood flow to brain
Which genes cause the formation of a smooth cortex?
Lys genes (pronounced liss)
Which chemokines do astrocytes produce?
MCP-1, IP10, IL-8, MIP1 and others
Polymicrogyria can be picked up by
MRI
Integration into a *global motion* estimate occurs in which area?
MT/V5 in the human *visual cortex* https://o.quizlet.com/1M2kA76xfszGP5njIlmYig_m.jpg
What are some special sense adaptations of animals?
Magnetic electrical fields and pressure to detect surroundings for fish or migration https://o.quizlet.com/aRv18aZ.463b1Idh-LIqbw_m.png
Parasol Cells
Magnocellular/M Pathway/M Cells
Perforant Path
Main input to the Hippocampus. Entorhinal Cortex -> Dentate Gyrus Neurons
(1) Maintenance of intra/extracellular ionic gradients by ion pumps
Maintaining Membrane potential
Supportive Evidence: LTP/LTD are robustly expressed in all
Major pathways in the hippocampus, a region of the brain profoundly important in memory formation
How does induction of LTP affect the amplitude of AMPA EPSC?
Makes it more negative (see previous question)
Conditional Expression
Makes the promoter turn on only in certain conditions. E.g. you put in tetracycline which turns on promoter
ICH Other causes
Malformations, infections, tumors, disorders and drugs
What are the (3) middle ear ossicles (very small bones)?
Malleus (hammer) Incus (anvil) Stapes (stirrup) https://o.quizlet.com/QNOkFXwh2WAYZr.U8oDmAQ_m.jpg
Polyneuropathy
Many
How long can hippocampal slices stay alive for?
Many hours after hippocampal dissection - they can even be grown in vitro for weeks
Where do cells hop off?
Marginal Zone
What do we see in neurological diseases?
Massive increase in CB2 receptor expression
What is the olfactory bulb used for by rodents? (3)
Mate selection, smelling danger, spatial awareness
Infection
Maternal, fetal/postnatal (chorioamnionitis)
Biomarkers
Measurable indicators of the state of disease Pitsburg, Radioactive Glucose, CSF Aß and tau etc.
Mechanoreceptors fire in response to
Mechanical Pressure/Distortion
The basilar membrane is a _____ _____ of sound frequency
Mechanical analyzer
What (3) nociceptive sensations?
Mechanical, Temperature and Chemical
The transduction channels in auditory hair cells are what type of gated?
Mechanically Gated, by the movement of stereocilia
The Organ of Corti is the site of
Mechano-electrical transduction
What are (4) receptors?
Mechanoreceptors Thermoreceptors Nocioreceptors Proprioreceptors
Myelencephalon
Medulla
The brainstem is made up of (3)
Medulla oblongata, pons, and midbrain
Mechanical Transduction: Muscle spindle detecting muscle displacement or position
Membrane has stretch sensitive channels, when the muscle is moved it opens and closes the channels, direct coupling with mechanical movement and influx of ions https://o.quizlet.com/zTb9jvllEq8danJrWIMvrA_m.png
Why do you see many mitochondria in neurons?
Membrane recycling, neurotransmitter generation, exocytosis - high energy demand
Phylogenetic Memory
Memories stored in genes - experience of a species over generations
AD: Clinical features - Impairment of/changes in (6)
Memory Language skills Visual-spatial orientation Abstract thinking Judgement Personality
For Immediate/Sensory memory, each modality has its own
Memory *register*
What do LTP and LTD underlie?
Memory formation at a sub-cellular level
What did Hebb (1949) propose?
Memory is stored in networks of neurons and changes in synaptic function in networks is memory storing (at synapses)
Other name for Midbrain
Mesencephalon
Seeing in average illuminated areas (dusk/dawn)
Mesopic
mGluRs are
Metabotropic
At the 5 vesicle stage, the Rhombencephalon divides into the (2)
Metencephalon, Myelencephalon
What did Susumu Tonegawa do?
Method to label neurons during memory formation
Different functional subsets of microglia exist. This means they express different and have different?
Microglia express different immunological markers *and* have different morphology/locations
Which cells have phagocytic properties?
Microglia, Astrocytes and Pericytes
Astrocytes are similar to _____ Cells
Microglial Cells
What is the autoimmunity function of Microglial Cells?
Microglial cells present antigens to other immune cells and therefore have an Antigen Presentation Capacity
Why is it difficult to observe these changes (increase in synapse number)?
Microscopy preparation kills biological material and so we cannot do before and after comparisions. Instead, we have a no LTP induced control and an LTP induced preparation, and we compare these.
Retina Projection: Superior Colliculus
Midbrain - Which control orienting eye movements reflexes
Retina Projection: Pretectum
Midbrain - Which control the pupillary light reflex
M-Cones, maximum sensitivity to
Middle-wavelength sensitive, Green, 545nm https://farm5.staticflickr.com/4064/4633177036_28512e1d76_m.jpg
Based on projections and functions, which are the (4) main classes of retinal ganglion cells?
Midget Cells (parvo) Parasol Cells (magno) Bi-stratified Cells (Koniocellular/K Pathway) *Melanopsin* Ganglion Cells (Photosensitive)
Stage Theory: Green/Red information is conveyed to which cells in the Retina and in the LGN?
Midget Ganglion Cells (P Cells) -> Parvocellular Neurons at LGN https://o.quizlet.com/GfO0M1zaix136jaL0QHwyw_m.png
The notochord helps to define the embryonic
Midline
Under most ambient conditions, most graded potential retinal neurons operate at or near which point?
Midpoint of their response range - so they can signal in response to more light and less light (graded potential)
Polysialylation (3)
Migratory Neuroblasts, Synaptic Plasticity, LTP learning and memory
The Neural Crest Cells follow an initial
Migratory route and give rise to other structures
HD Treatments (7)
Minocycline Coenzyme Q/Q10 Latrepirdine Creatine Monohydrate GABA Agonists Antidepressants Neuron replacement or Gene therapy
The axons of the sensory neurons synapse with the dendrites of _____ cells in the glomerulus
Mitral Cells https://o.quizlet.com/QhdWQTNHahKjK1n7.qHjag_m.jpg
What are the (4) sensory system attributes?
Modality (type), Location, Intensity and Timing
Stage Theory: Why called the stage theory?
Modern model of normal colour vision which *incorporates both the trichromatic theory and the opponent colour theory* into two stages
Prevention of Ischemic Strokes and TIAs
Modify Risk Factors Anti-platelet drug (asprin) Treatment with anticoagulants Carotid Endarterectomy
Substantia Nigra
Modulates *mood* and *movement*. Fibres bidirectionally connect this to the *striatum*. It contains large, black, dopamine producing cells.
Sialic Acid molecules impair the capacity of glycoconjugates to interact and thereby act as
Modulators of Cellular Interactions https://o.quizlet.com/1eJBBSxeKbzKcQr.9lHtEw_m.png
Chemokine
Molecule that is secreted by one cell, creates a gradient to another cell, and the other cell will follow the gradient (attractant) - soluble chemical signal
However, these studies have focused on
Molecules involved in synapse plasticity, required for changes in synapse strength
Neurotrophic Factors
Molecules that support neurons, help control the growth and survival of the neurones, by generating an environment around the neurons
Muscle Spindles
Monitor muscle length, and the rate of change of length
Golgi Tendon Organs
Monitor muscle tension
Joint receptors
Monitor position, signal hyper extension/flexion of the joint
People who see black and white?
Monochromats https://o.quizlet.com/.8hdIt4mRBtNe4bUth.JYw_m.jpg
What is the Microglial Cell origin?
Monocytic and Myeloid
Myotatic Reflex is the only
Monosynaptic reflex in body
How long can stable recordings be made for?
Months
Supportive Evidence: LTP/LTD has been shown to last for how long in awake, behaving animals (rodents)?
Months
What are the advantages of animal models? (2)
More complex than cell cultures Can determine proof of concept
4. Lacunar infarct (LACI)
More focal
Benefits of using the H-Reflex (Hoffman) over the conventional Myotatic Reflex?
More precise Also yields EMG response
Laminar Cell Death (define and what structures of brain affected)
More severe Striatum and Cortex
Hippocampal Lesion tests in mice (2)
Morris Mater Maze and Radial Arm Maze https://o.quizlet.com/5eBFD2R2CSYreQX8kpUJ9A_m.png
Ischaemic stroke (Infarction)
Most common (80-85%) Loss of blood flow to part of the brain/spinal cord → poor oxygen/glucose → necrosis
In a normal, healthy person (CNS), where do we see CB2?
Mostly in the brain vasclature
The M Cells are _____ detectors
Motion Detectors
Large Ganglion Cells are concerned with processing
Motion detection and alerting the animal to threatening, moving visual imagery
Association and Motivation in Memory
Motivation helps to strengthen memory
Somatosensory Association Cortex projects to
Motor Cortices (voluntary movement)
Broca's Area function and location?
Motor aspect of speech, Inferior Frontal Gyrus
Exner's Area function and location?
Motor control of hand for writing, Middle frontal gyrus
Neurological injury + neurodevelopmental handicaps include (4)
Motor dysfunction, lower IQ, cognitive problems, behavioural problems
Find Engram: Result?
Mouse froze without foot shock, when memory recalled
Implanting False Memory: Step 1
Mouse placed in Box A (red triangle) → learns about Box A (only beeps) → formation of Memory A
Implanting False Memory: Step 3
Mouse placed in Box A → Freezes in response to sound only (false memory generated)
Implanting False Memory: Step 2
Mouse placed in Box B (grey square) Foot shocks accompany beep Memory A activated (recalled) via ChR2 stimulation with blue light https://o.quizlet.com/iwCJfcR.KSNWONh3TLy.Eg_m.jpg
Implanting False Memory: Step 4 (optional)
Mouse placed in Box C → Mouse does not associate any Box A/B memories with this new Box so → New Memory
Athetosis
Movement away from midline (opposite to normal)
M Cells signal temporal variations in
Movement of a stimulus
Locomotion
Movement of entire cell, including its leading and lagging process, over considerable distance (Glial guided radial movement of neurons) https://o.quizlet.com/p9jh2HkPzrUkNGyLShroDg_m.png
Sensory Transduction: Stage 1
Movement of the Basilar Membrane Up and Down https://o.quizlet.com/SXzmiIsET9GPjlyKWDOKww_m.jpg
How is hyperpolarizing the membrane potential related to the firing threshold?
Moving the resting membrane potential away from firing threshold (making it more negative)
The M Cells are (size compared to P Cells)
Much larger than P Cells
Endothelium of the BBB have *MDR* Proteins
Multi Drug Resistance Proteins
Difficulties: Learning likely involves activation of
Multiple pathways and brain areas
Long Term Memory involves
Multiple receptors, kinases, transcription and translation leading to morphological changes https://o.quizlet.com/bgHIFgD7gFsYtYu2n-1ekg_m.jpg
Type III and IV Fibres project to
Multiple spinal segments - branches - to yield response from many muscles
Sources of synaptic inputs into αMNs (4)
Muscle Receptors Segmental (Spinal) Interneurons Propriospinal Neurons Descending Tracts
Myotatic Reflex utilises which physiological receptor?
Muscle Spindle
Proprioceptors types (4)
Muscle Spindles, Golgi Tendon Organs, Pain Receptors and Joint Receptors
Mesoderm forms (2)
Muscles and *CT*
Why Transgenic Models < Gene Therapy Models?
Mutation only expressed in specific cells (e.g. dopaminergic cells in PD) ^ also used to infect one side and use other side (of brain) as control Sometimes mutation in transgenic kills model before adulthood - can't study adult
White is due to _____ made by _____ in the CNS
Myelin, oligodendrocytes
Stretch Reflex is (2) reflexes
Myotatic/Tendon/Monosynaptic Reflex/Knee Jerk H-Reflex (Hoffman)
AMPA receptors are permeable to (2)
Na+ and K+
NMDA receptors are permeable to (3)
Na+, K+ and *Ca2+* (highly)
The left part of the visual field is projected onto which part of the retina? (assuming left eye)
Nasal part of the retina (right)
Classical Conditioning
Natural reflex is modified by associating its normal triggering stimulus with an unrelated stimulus (food with bell)
Why animal models > cell culture models?
Necessary to *model a complex disease* and *test new drugs* before human clinical trials.
What are the (8) layers of the retina? (Outside in)
Nerve Fibre Layer Ganglion Layer Inner Plexiform Layer Inner Nuclear Layer Outer Plexiform Layer Outer Nuclear Layer Photoreceptor Outer Segments Pigment Epithelium https://o.quizlet.com/91lvHZWO.FCrBCrJTrfSkw_m.png
Motion aftereffect is believed to be the result of?
Neural Adaptation
Where will the brain and spinal cord end up sitting?
Neural Groove
Neural Precursor Cells are ____ ____ cells that give rise to (4)
Neural Stem Cells, more stem cells, neurons, astrocytes and oligodendroglial cells
The Neural Crests come together to from the
Neural Tube https://o.quizlet.com/Fy8w548bO5acv4wswrHESw_m.png
Neural Fatigue
Neural adaptation of neurons stimulated by downward movement reduces their baseline activity, tilting the balance in favour of upward movement
Phantom Limb: Injury?
Neural inhibition lost, so other areas spread https://o.quizlet.com/2TaZMI5jsmJZagorQmjmgA_m.jpg
Radial Migration (2)
Neuroblasts migrate on and guided by radial fibers. Somal Translocation of Cell Body
Neural Precursor Cells directly above the notochord form the _____ (2) through the process of _____?
Neuroectoderm or Neural Plate, through Neurulation
Lewy Bodies contain
Neurofilamants
Another name for Glia?
Neuroglia
Necrosis results in
Neuroinflammation
What type of classification of human microglial subsets is often based on appearance?
Neurological
>50% of preterm infants have (2)
Neurological injury + neurodevelopmental handicap
The olfactory receptor (in contrast to other sensory organs) is a
Neuron - nerve terminals in the mucosa of the nose and the other end at the olfactory bulb https://o.quizlet.com/7XfNx1ofeZqWrBUw9aytWw_m.jpg
[Diagram] Responses of olfactory receptor neurons to selected odorants
Neuron I responds similarly to three different odorants. In contrast neuron 2 responds to only one of these odorants. Neuron 3 responds to two of the three stimuli. https://o.quizlet.com/VRFzXTKPOeWT572G4fUjsg_m.jpg
Physiological Recovery after stroke (3)
Neuronal Plasticity Recruitment of 2ndary motor areas on ipsilateral hemisphere Activation of homologous areas of contralateral hemisphere
Cerebral Blood Flow <10 ml/100g/min
Neuronal cell membrane function is severely affected
What are (8) cell types in the human CNS?
Neurons *Glia*: Oligodendrocytes, Astrocytes and Microglia *Others*: Endothelial Cells, Pericytes, Fibroblast like and Stem Cells https://o.quizlet.com/UkA7J6-DMTl5ol9qu5-BHA_m.png
Ice Cube Model
Neurons (a mixture) respond to: Interaural Time Delay Interaural Intensity Difference https://o.quizlet.com/3WjwZMmTAvZKcFSWz4qdEQ_m.jpg
What does experience-dependent learning require?
Neurons acquiring responsiveness to new stimuli *and* losing responsiveness to previously effective stimuli
Cerebral Blood Flow <5ml/100g/min
Neurons cannot survive for long
Modality: Specificity of response underlies *labelled line*
Neurons from specific receptors are modality specific (they only care about their sense)
In the rodent brain, there is a constant supply of _____ to which structure?
Neurons to the Olfactory Bulb
In which cells don't we see expression of CB2 (2)? Where do we see a little bit of expression (1)?
Neurons, Astrocytes (maybe a little on microglial cells)
What is MPTP?
Neurotoxin accidently made by drug addicts that induces PD in humans (death of dopaminergic neurons)
MPTP
Neurotoxin, affects SN dopaminergic neurons, variable response
What (2) things are required at the synapse for synaptogenesis?
Neurotransmitters and Receptors
Astrocytes are important sources of
Neurotrophic Factors
Brain Derived Neurotrophic Factor is a
Neurotrophin
Other name for BBB
Neurovascular Unit https://o.quizlet.com/-W0n0pdVRu.KjenObI9OtA_m.png
Learning
New information acquired by NS, leads to change in behaviour
Name of pathway from SN -> Striatum?
Nigrostriatal Pathway
Can you get activation of phosphatases is the presence of phosphatase inhibitors?
No - duh
How long does CP last?
No cure - life long
Genetic (2)
No direct genetic link Hereditary predisposition and familial pattern of inheritance (11 genes)
(Non-cystic) Diffuse White Matter (myelination) Injury
No holes but selective death of oligodendrocytes (less myelin, less white)
What happens if we block SNA activity with drugs?
No vasoconstriction → CBF remains normal → Brain activity not suppressed → more microseizures
Are Microglial Cells all the same?
No, they are a mixture of cells (different functional subsets) that can have different localised functions
Are Neurons self sufficient?
No. They are not sufficient to look after themselves, need glial cells to help out (astrocytes are critical in their survival)
Flexion (withdrawal) Reflex Receptor
Nociceptors
Pain Receptors
Nociceptors in skin
What inhibits BMP4?
Noggin and Chordin
Oxidative Stress
Noise exposure -> overproduction of free radicals by mitochondria in OHCs -> damage cells
What are (3) causes of hearing loss? (Neurosensory Pathology)
Noise-induced hearing loss Age-related hearing loss Drug-induced hearing loss (ototoxicity) (the mycin drugs)
What are the two amyloid processing pathways?
Non-Amyloidogenic and Amyloidogenic https://o.quizlet.com/V1zl0QGZFZUh2rqomjhE-Q_m.png
Anterior/Lateral Spinothalamic Tract - Type of sensation (2)
Non-Discriminative Pathway Anterior: Crude Touch and Pressure Lateral: Pain and Temperature https://o.quizlet.com/1vD50NogugBeRhnX8IAKFg_m.jpg
Desialylation (1)
Non-Migratory Neurons
Damage to Primary Somatosensory Cortex leads to partial loss of... (also why?)
Non-discriminative sensation (can't accurately localise), not complete loss as tracts *project to other areas as well*
The neurons that migrate from the ventricular layer up are ___-______ neurons?
Non-dividing neurons
Just Dopaminergic Neurons affected in PD?
Non-dopaminergic cells are also affected elsewhere in the brain
HD symptoms early in life?
None
Innate Immunity
Nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body
Most people can live with Lissencephaly or Polymicrogyria and
Not even know lewl (asymptomatic)
How is bitterness reception perceived?
Not possible to distinguish bitter compounds only that they are "bad"
What are the afferent OHC neurotransmitters?
Not quite clear, but ATP probs
This experiment was being done on the hippocampus on one side. What was happening to the contralateral side?
Nothing - no stimulation so no potentiation
BMPs are produced by
Notochord
Where does the Facial Nerve synapse?
Nucleus of the solitary tract (Gustatory nucleus)
Reverse Transduction
OHC Stereocilia - the electrical signals of hair cells evoke a mechanical output (rather than sending information to the brain)
Efferent Fibers innervate mainly the _____ (Type of cell). What is the function of these cells?
OHCs - Regulate excitability depending upon feedback from brainstem auditory pathways. This contributes to dynamic changes in hearing sensitivity as ambient sound levels change.
What are the most sensitive cells in our ears prone to pathology (leading to deafness)?
OHCs - loss of these = loss of amplification of sound, 50-60dB decrease in hearing https://o.quizlet.com/xiPK9g3Em2cFPggHnN3eMw_m.jpg
Ventral "What" Pathway/Stream
Object Processing - Colour, texture, pictorial *detail*, shape and size
Braille: What evidence for visual cortex being recruited for somatosensory function?
Occipital lobe impairment → Braille recognition disrupted
What are the (5) junctional proteins used in the BBB?
Occludin Claudins ZO-1 (Zona Occludens) Cadherins JAMs (Junctional Adhesion Molecules)
3. Lacunar infarcts
Occlusion of a small penetrating branch of a larger cerebral artery. Penetrating arteries supply the deep white matter.
1. Total anterior circulation infarct (TACI)
Occlusion of internal carotid artery or middle cerebral artery. Clinical features: (1) Focal higher cerebral dysfunction (2) Homonymous vision defect (3) Unilateral motor/sensory deficit
3. Posterior circulation infarct (POCI)
Occlusion of vertebral, basilar or posterior cerebral artery. Clinical features: (1) Motor/sensory deficit (2) Messed up eye movements (3) Cerebellum problems (4) Homonomous vision problems
Which species have the retina at the front?
Octopus and molloscus
Brief olfaction mechanism?
Odorant molecules activate a G Protein receptor (Adenylate cyclase and cAMP) resulting in activation of the neuron/receptor https://o.quizlet.com/9UVF-ZesCkd35zJ9JkphbQ_m.jpg
What is an example (mouse) of Accessory olfactory systems?
Odors from female mouse cause male mouse to mate, but odors from other males may make him aggressive
Spatial arrangement of receptors enables resolution
Of fine detail of stimulus or environment
Spatial arrangement of receptors enables descrimination
Of size and shape of object
What structure is first to be affected in Alzheimer's or Parkinson's?
Olfactory Bulb - loss of sense of smell
In Alzheimer's and Parkinson's, the areas become affected, starting from the _____ and moving through and up to the _____ in Parkinson's
Olfactory Bulb, Substantia Nigra. https://o.quizlet.com/Kr-dp9DaiikiPTrbvNZOgQ_m.png
Name for smell cortex?
Olfactory Cortex
What is the olfactory pathway starting from the receptors in the nasal mucosa?
Olfactory Receptors -> Olfactory Nerve (I) -> Olfactory Bulb -> Olfactory Tract -> Pyriform Cortex https://o.quizlet.com/g-jJ7zxuOHQkcc.ax0fCRw_m.jpg
How do we test and develop new drugs?
On disease animal models
Spatial arrangement of receptors provides information
On location of stimulus source on body or in space
On which part of the cells and why is PSA used?
On the *spines* of dendrites that *forage* for new connections, putting PSA on top allows for a smooth slide through
Which hypothesis is used for olfactory genes?
One gene, one receptor
Each receptor is specialised to
One or few specific odorant molecule
Of the three sensory cells, how many seem to be receptors?
Only 2
Each muscle fibre is innervated by
Only one MN at a single NMJ
Ribbon Synapse (only present in 2)
Only present in the *ear and the eye*, simultaneous and fast release of neurotransmitter
LTD Specificity
Only synapses that are stimulated by the 1 Hz protocol are depressed
Input Specificity
Only the activated synapses are potentiated (other synapses on the same neuron are not)
Sensory System Attribute: Timing
Onset, duration and offset of stimulus coded by frequency of the neural activity https://o.quizlet.com/kuPjWm4b0df.Ljd8kkQ11Q_m.png
What happens as a result of the presynaptic glutamate release?
Opening of glutamate receptors on the postsynaptic membrane -> conduction of current (influx of Na) -> action potential
What is the expression pattern of the CAM molecules?
Ordinarily not expressing them, but expression elevated during inflammatory response
What is the central part of the cochlea?
Organ of Corti
High level of stress/injury destroying affecting the IHCs and OHCs leads to?
Organ of Corti is completely collapsed, so complete deafness (hearing aids are not helpful)
What are (2) simple aspects of the hippocampus? What does this enable?
Organisation and Architecture. This enables stimulation of specific axonal paths and recordings from specific postsynaptic pyramidal cells in a certain area
What is the collective name for the 3 ossicles?
Ossicular Chain
How do we detect the location of sound?
Our brain interprets the time difference between the sound reaching one ear vs the other ear
How we interpret the words depends on
Our experience!
The decline of sense of smell with age affects
Our sense of taste and food will lose its flavour as we age
Environmental Toxins
Outbreak in drug addicts MPTP - Narcotic Analogue
What are the (2) Hair cells and (%)??
Outer (75%) and Inner (25%) Hair Cells
How did the patients involved in the trial respond?
Outraged - they thought they were getting better. 4 of 6 on trial were actually on placebo
Pure Tone Audiograms are recorded in normally hearing subjects
Over the course of their life
Structural Plasticity
Over time stable enlargement of cortical representation can occur
(2) Production of ATP (energy) under aerobic conditions
Oxidative Phosphorylation Glucose → 38 ATP + 6 CO2 + 6 H20
Limiting factor to maintain energy production is what and is not what?
Oxygen (≠ glucose)
Partial Pressure is the driving force for
Oxygenation in body
Which groups interact between leukocytes and endothelial cells that causes the leukocytes to roll along the endothelium?
P-Selectin on endothelial cells and Oligosaccharides on the leukocyte cell surface
What are the (2) drivers of acidosis?
PCO2 and Lactic Acid
Microglia can respond to cytokines during inflammation to increase their _____ activity
PHAGOCYTIC
Neural crest becomes the PNS/CNS?
PNS https://o.quizlet.com/1RW.AQf4cuprezjhkvwBYA_m.png
Blood Oxygenation depends on (3) factors
PO2 dissolved in the blood Hb O2 saturation Hb concentration
Cells in the Rostral Migratory Stream have what on them that helps them with locomotion?
PSA (a sugar chain) on the outside of NCAM (on the outside membrane) = Polysialylated-neural cell adhesion molecule
Nocioreception
Pain sensation
Conditioned Learning
Pair a novel stimulus (chocolate) with a pre-existing stimulus (telling penny to be quiet) to generate a response (she stops talking)
What is more commonly used to induce LTP today?
Pairing
By which (2) mechanisms can leukocytes infiltrate the BBB?
Paracellular or Transcellular
Complex Deficits
Parietal (Association Cortex or other somatosensory areas) Damage
Optic Disc
Part of retina at optic nerve entry, lacks visual receptors so creates blind spot https://o.quizlet.com/i/NOVvlYLASZLc3AZKpDWGTg_m.jpg
A visual field defect is a loss of
Part of the usual field of vision
What are the limitation of animal models? (3)
Partial Model (not perfect as human would be) No co-morbidity (in practice we see multiple risk factors contributing to disease) Have to extrapolate rodent physiolgoy to human physiology
Pathological
Partial or total loss of memory From CNS injuries or disease
How is the intensity of sound distributed when the high frequency sound comes from any *oblique angle*?
Partial sound shadow for one ear, some reduction in intensity https://o.quizlet.com/6GSLTM7GSu64leSUY57YeA_m.png
When they have reached the appropriate location, what happens to the neurons?
Particular genes (for *growth/transcription factors*) are turned on, which leads to the *growth* of axons, dendrites and synapses.
Rhythmic Motor Patterns are?
Partly voluntary, partly involuntary
Midget Cells
Parvocellular/P Pathway/P Cells
Frequency distribution along the human cochlea basilar membrane is known as _____ Tonotopy
Passive Tonotopy https://o.quizlet.com/6jUFN8-v7Tw8TajWB6x-Gg_m.jpg
Monochromats are usually associated with
Pathology later in life
Farnsworth Panel D-15
Patients are asked to arrange 15 coloured caps in sequential order based on similarity from the pilot colour cap
Normal Macroscopic anatomy of striatum and cerebrum?
Pear shaped striatum and thick, tightly packed gyri
Braille: What else changes?
People who read braille often blind - areas involved with sight (Occipital Lobe) used for somatosensory (reorganisation and redistribution)
What is a theory of the Motion Aftereffect?
Perception is coded as the balance among the baseline responses of neurons coding all possible directions of motion
Trisynaptic Loop (3)
Perforant Path, Mossy Fibres, Schaffer Collaterals https://o.quizlet.com/WjPV.048fF5ioZPa5l6x5A_m.png
Ischaemic penumbra
Peripheral - Electrical failure and dysfunction of neurons Salvageable if early re-perfusion
Somatosensory Injury can occur in (4)
Peripheral Nerve Spinal Cord Thalamus Cortex
Compare and contrast swelling in peripheral tissues and the brain
Peripheral tissues can have oedema and swelling, no problem. But for the brain it is encased in a skull so there is nowhere for that pressure to go
What cells are in close proximity or wrapped around the vessel?
Perivascular Microglial Cells
What else can Microglial Cell be called (types)? (7)
Perivascular, foamy, phagocytic, non-phagocytic, antigen presenting (disease), activated (inflammation) and ramified
Phantom Limb: Loss of input from amputated limb?
Permanent *reorganisation* of the cerebral cortex via *sprouting* of other axons
What are the negative effects of pregnant mothers taking cocaine?
Permanently *stall* out the neuron as it is migrating on the Radial Fibre. Neuronal function depends on their position, and if the cells are stalled, they will end up in the wrong location and formation of other cells is affected
What is CaMKII known to do?
Phosphorylate many proteins
Seeing in well illuminated areas (day) (about 0.03 cd/m2)
Photopic
Different Types of Memory/Learning (4)
Phylogenetic Association and Motivation Modality Dependent Meaningfulness
Engram
Physical embodiment (change associated with storage) of memory in neuronal machinery
Senses detect and convey _____ information about _____ and _____ environment
Physical information about external and internal environment
The Black Box Analogy: Output
Picture (Perception - not just seeing)
What are the characteristics of the neurons that degenerate in Parkinson's? (5)
Pigmented Melanin-containing Located in Pars compacta (substantia nigra) Project to striatum (caudate nucleus and putamen) Use Dopamine (as NT)
Autonomic temperature responses?
Piloerection, Vasoconstriction/dilation, Sweating, Shivering, Thermogenesis
Causes of Fetal Hypoxia-Ischemia (8)
Placental abruption Umbilical cord knot Twisted umbilical cord Meconium staining Prolonged birth Cardiovascular instability or congenital heart disease Cardiorespiratory arrest Preterm lung development
Pre-Motor Cortex
Planning of movement for finer control
As the cells differentiate, the organism looses _____ in favour of _____
Plasticity, function
How can we (scientists) measure interaural time delay? (Low frequency sound)
Play sound at left ear, AP will arrive at Superior Olivary Complex (SOC). Some ms later, sound will elicit AP at the right ear. The left ear APs will travel further along the SO axons in the time it takes for the APs from the right ear to reach the SOC. APs meet up closer to the right and fuse to form an AP that represents sound coming from the left. https://o.quizlet.com/FjjKzPoeeah32p74afyILg_m.jpg
What does smell evoke?
Pleasant and unpleasant responses
C (IV) Fibres respond to all three pain sensations. This is known as being
Polymodal
What does the fourth ventricle have in front and behind it?
Pons in front, cerebellum behind it
Field of Vision
Portion of the surrounding that can be seen at one time (what you can see with both eyes open) https://o.quizlet.com/V42cX-MAmE18e00Ulw4YPg_m.jpg
Sensory System Attribute: Location
Position of stimulus in space (spatial component)
Types of Operant Conditioning (3)
Positive reinforcement, Negative reinforcement and Punishment https://o.quizlet.com/D0gSqTqsvlOa6pyT9JDVeA_m.jpg
Why do the muscles change their physiology?
Possible involvement of *trophic factors* released simultaneously with ACh
Spinal Cord Injuries (4)
Posterior Cord Syndrome Anterior Cord Syndrome Brown-Squared Syndrome (hemisection) Central Cord Syndrome
Postsynaptic Apparatus is made up of (2)
Postsynaptic density and Postsynaptic receptors
(2) Perinatal Brain Injury types (temporal)?
Pre Term and At Term
If there is more co-activation of the presynaptic and postsynaptic membranes there will be more Ca influx through the NMDA receptor. Therefore the level of Ca entering the NMDA receptor is a measure of
Pre and postsynaptic co-activation
Aetiolgoy
Predominantly Genetic 1:1 M:F
Technical term for Age Related Hearing Loss?
Presbyacusis
CB2 expression relates to presence of _____ and the activation of _____
Presence of Immune cells (leukocytes) and activation of the BBB
P Cells are good at signalling (2) of a visual stimulus but poor at signalling (1)?
Presence, colour and duration, stimulus movement
What are the (3) key genes that cause familial AD?
Presenilin 1, 2 and APP
What are the two CNS synapse components?
Presynaptic Terminal and Postsynaptic Apparatus
What else increases as people age? (2 examples)
Prevalence of neurodegenerative diseases and dementia, especially cerebrovascular disease and stroke
COMPT inhibitors
Prevent breakdown of dopamine in synaptic cleft
Treatments of acute ischaemic stroke (3)
Prevent thrombus/embolism Thrombolysis Mechanically remove thrombus
Supportive Evidence: What does Genetic removal of the CaMKII gene do?
Prevents LTP and induces learning deficits in rodents
(1) Insult Phase
Primary Insult Cannot prevent - cells destroyed in the event gone E.g. Hypoxia Insult to foetus
What are (3) key structures in the Frontal Lobe?
Primary Motor Cortex, *Pre-motor Cortex* and Association Cortex
(5) Somatosensory Brain Regions
Primary Somatosensory Cortex (S1) Secondary Somatosensory Cortex (S2) Somatosensory Association Cortex Cerebellum Thalamus
However, motion detection logic also applies to
Primate cortex, human physiology, psychophysics and to the vertebrate retina of some species (mice, rabbits)
During brain injury, what do Microglial Cells produce? (Be specific)
Pro-inflammatory Cytokines
During neuroinflammation the endothelial cells respond to what (and 2 examples)?
Pro-inflammatory cytokines, Interleukin 1, TNFα in the blood
Types of Non-Declarative Memory (3)
Procedural, Motor skills and Emotional
What can Astrocytes do being in close proximity to neurons?
Produce and metabolise NT via connections with neurons
Meaningfulness and memory
Professional Chess Player vs. Beginners/Logical positioning vs Random positioning https://o.quizlet.com/mE2PjJGvdmgVol8qk.PQ.Q_m.jpg
Microglial Cells are known as the brain's (not RICs)
Professional Phagocytes
Apoptosis
Programmed cell death
During or shortly after birth injuries caused by (3)
Prolonged labor, cord problems, blood pressure instability
Transgene Expression Cassette is made up of (4)
Promoter - Cell Specific and regulatable Transgene - Report (GFP) + Gene of interest Regulatory Elements - Conditional
Example of Transgene Expression Cassette
Promoter - Tet on (tetracycline addition turns it on) Transgene - BDNF and GFP Infect animal with 6OHDA to induce PD and see if BDNF protects cells from dying
I → IV types of information carried?
Proprioception → Touch → Pain/Temp
Brodmann Area 3a
Proprioceptive
Posterior Spinocerebellar Tract
Proprioceptive information from *limbs and body*
Other name for Forebrain
Prosencephalon
What are the (2) forms of dichromacy?
Protanopia and Deuteranopia
Normal function of the *huge* Huntingtin (Htt)? (3)
Protein Transport Anti-apoptotic ↑neurotrophin levels
c-fos
Protein which is expressed (transcribed/translated) in active cells that hold the memory
Overproduction of dendritic branches lead to
Pruning
What happens after the maximum synapse number is reached?
Pruning
Common: Cell in dorsal root ganglion is
Pseudounipolar https://o.quizlet.com/a-O5zLHXZ2JcF-yEUxLA3Q_m.jpg
How was GDNF administered in humans?
Pumps installed in abdomens and tubing travelled to substantia nigra (both sides) → GDNF infused periodically into brain
What is a common Subjective Method?
Pure Tone Audiograms https://o.quizlet.com/3QgY4t3JfPp1hNJotgMVNQ_m.jpg
Pure Tone Audiogram
Pure tones are played to the ear and the subject indicates when they hear the sound
How do we test proof of concept?
Putting animal models through tests
PSA-NCAM is like
Putting soap and water on your before going down the hydro slide to reduce friction, you don't form any 'connections' with the slide
After Neural Tube Closure, what begins to form, that will form the scaffold on which the neurons will travel up?
Radial Glial Fibres made by Radial Glia https://o.quizlet.com/8UTYHMw6hIfx-6MnXTKC-A_m.png
Which type of pattern does this form?
Radial Inside-out pattern https://o.quizlet.com/glVsngcPQkt2XQVVux47QQ_m.png
What are the two forms of migration?
Radial and Tangential
PET Scanning (+ 2 examples)
Radioactive tracer binds to certain molecules in the brain and can be scanned. (1) Radioactively labeled glucose (decreased energy metabolism in AD) (2) Pittsburg Compound B binds Aß
Synapses enable _________, forming complex _________ through the brain
Rapid communication, neuronal circuits
Remodelling process for synaptogenesis is rapid during _____ but slower during_____
Rapid during development, slower during adulthood
What was the rat model experiment setup that involved Allopregnanolone?
Rats socially isolated (SI) to induce depression, which lead to subsequent loss of motivation
When does Ischaemic penumbra → Core Ischemic Zone?
Re-perfusion is not achieved early enough Severe biochemical changes due to ischemia
AADC
Reached Phase 1 trials twice, on it's third phase 1 trial as we can't get dosage right
Find Engram: Step 3 - Reactivate?
Reactivate/recall memory without stimulus Apply blue light with *optical fibre implant* → stimulate memory
Loss of tissue often replaced by?
Reactive Astrocytes
How is sound localisation manifested at the Superior Olivary Nucleus? (Low frequency sound)
Receives neurons from both ears -> there are a range of neurons that fire in response to different Interaural Time Delays (e.g. a subset of neurons respond to 0.8ms, so effectively they are activated when sound comes from directly left or right) https://o.quizlet.com/C6DwIt2hjLydmah-aK.gKQ_m.jpg
Postsynaptic Apparatus
Receives neurotransmitter, converting chemical signal back to electrical
Spatial arrangement is the
Receptive Field (I.e. only *that* receptor receives the stimulus, and nothing around it)
Ganglion cells have
Receptive Fields
Stage Theory: What are the (2) stages? (not trichromatic/opponency)
Receptor Stage and Neural Processing
Vision
Receptor is retina, light is directed to this, visual cortex https://o.quizlet.com/uU-OaQPaIKYxtceolNL7-A_m.png
What are the (5) elements of Spinal (+Brainstem) Reflexes?
Receptors (Physiological) Afferent (sensory) Fibres Central Synaptic Relays Efferent (motor) Fibres Effectors (muscles)
Modality: Receptor Specificity
Receptors are *morphologically* specialised for specific form of energy
Hearing
Receptors in the ear pick up the vibrations https://o.quizlet.com/Mxs-ZmCl9JF94jyFDirUSA_m.png
How is Dichromacy inherited?
Recessive, sex linked
What does the Myotatic Reflex manifest?
Reciprocal Inhibition https://o.quizlet.com/1fZHev1TFLxfBt8rjI3BvQ_m.jpg
What does our retina and brain do after separating intensity and wavelength?
Recombines them into colour perception
Compound Potentials
Recorded at a distance from origin, sum of unit potentials
Compund Potential Example: Electrocochleography
Recording compound potential, insert electrode through tympanic membrane to round window, shape different from AP - technique used in humans https://o.quizlet.com/OoIHuE8YdymsQlY2g952Vg_m.jpg
Objective Methods
Recordings of electrical activity at various stages along the auditory pathway (cochlea -> cortex)
Most injury occurs during when and when not?
Recovery, not primary insult
What does ACh esterase do?
Recycles ACh → AcetylCoA + Choline at synapse
Components of Light
Red to blue parts https://o.quizlet.com/fEMjIHBG74pLXGDN5CRIzg_m.png
Colour of S Type/Type I?
Red, ↑myoglobin, ↑blood supply
What is Post Asphyxial Hypoperfusion?
Reduced brain blood flow after the reperfusion phase, as a protective response
Hypomimia
Reduced degree of facial expression
Abnormal gait
Reduced or absent arm swing, shortened stride length
What is the proof of concept of Allopregnanolone?
Reduced the time mice stay immobile in the water (i.e. less depressed even with isolation)
Blocking CB2 has which (2) effects?
Reduces infiltration of blood leukocytes Protective function towards the BBB
miRNA: With added BDNF
Reduces specific miRNA levels and increases expression of specific proteins (<4%)
Hemineglect
Reduction in *attention* to and *spatial awareness* of the contralateral side of body (relative to damage)
What do Cajal Retzius Cells produce? What does this do?
Reelin, tells the cells to hop off from the Radial Fiber and *form the next layer*
*Value*/Tone/Brightness
Reflectance and luminosity
Brainstem and spinal cord are for what type of movements? (2)
Reflex Movements Rhythmic Motor Patterns
The tectum/colliculi are involved with
Reflexes/body orientation (Neck/eyes) towards a stimulus
Pure Tone
Regular wave of a single frequency https://o.quizlet.com/1gCauVZRFT1k9qoiEzB0VQ_m.jpg
The scala vestibuli and scala media are separated by?
Reissner's Membrane
What is a better way of classifying cells?
Relating the name to the cells function, however this can get confusing
Sensory Transduction: Stage 5
Release of neurotransmitter from these Hair Cells -> Sound information is sent to the brain
What does tetanic stimulation of the presynaptic terminals result in?
Releases large amounts of glutamate that activates AMPA receptors on the postsynaptic cell and results in depolarisation of the postsynaptic cell
What does dephosphorylation of AMPA receptors lead to?
Removal of AMPA receptors from the postsynaptic membrane https://o.quizlet.com/j4G.24M1PywDmWgF6a0ycQ_m.png
Sources: Segmental (Spinal) Interneurons (example think FF6/7)
Renshaw Cells
(2) Recovery Phase can be broken into (3) (and durations)
Reperfusion (0-30min) Latent (30min - 6h) Secondary (3h - 2/3d)
What happens after the insult is removed?
Reperfusion phase - CBF restored in first ~30 minutes https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
What was applied to the Perforant Path of anaesthetised rabbits?
Repetitive trains of stimuli
How can gene therapy be used? (3)
Replace damaged genes with normal ones Insert genes that synthesise therapeutic molecules that prevent cells from dying Insert genes that code for enzymes involved in metabolic functions
How can we test if our viral vector is working?
Replace viral genes with GFP - if cells glow green your retrovirus worked
History of gene therapy
Replaced damaged gene with corrected gene in children with Bubble-Boy Disease in late 1990's → cured 9/10
Viral vectors cannot induce further cell infection. This is called?
Replication deficient
What is used to insert genes into a patient's DNA (be specific)?
Replication-deficient viral vector
YFP
Reporter gene (enhanced yellow fluorescence protein) → can visualise when expressed (when memory recalled)
What is cell reprogramming?
Reprogramming mature cells to become pluripotent
What is the relationship between normal sensation and nociceptive sensation?
Requires greater stimuli (intensity) to evoke noxious response (weaker will evoke normal thermoreception etc.) https://o.quizlet.com/DpYhhHoO72U03cjjiLKHCQ_m.jpg
The density of receptors define the
Resolution of the stimulus https://o.quizlet.com/82nm.WPjR7m3B-pTCh1OkA_m.png
Presynaptic Terminal
Responsible for transmitter release, converting the electrical signal to chemical
(6) Cardinal Clinical Features
Rest tremor Cogwheel Rigidity/Increased Tone Bradykinesia/akinesia Abnormal gait Abnormal postural reflexes Hypomimia
Current flow through the AMPA receptor can be measured when the postsynaptic cell is close to its
Resting membrane potential (~-65mV) https://o.quizlet.com/O9ptlpTafpvOpYCCp8o9wg_m.png
Recovery Phase: Reperfusion
Restore oxygen/blood flow to brain
Examples of Extrareceptors? (other modalities)
Retina (powerful), vestibular, auditory, olfactory, skin https://o.quizlet.com/WfwbtKE-7Gz1GJoovUXqMQ_m.png
The cells that travel up the radial fibers have to do what to their processes when they reach their appropriate location?
Retract their leading and trailing processes and differentiate
What takes Long-Term → Short-Term/Working memory?
Retrieval
Types of amnesia (2)
Retrograde and Anterograde
Unconscious Proprioception (example)
Righting Reflex - stop body from falling over
Involuntary Movements include (5)
Rigidity Extrapyramidal Hyperkinetic Movements Chorea Athetosis Late stage hypokinesia
Which (2) cell types are the only ones that process light in the retina?
Rods and Cones
Factors: Dark Adaptation
Rods and cones recovery function
Root Hair Plexus
Roots of hairs
The neurons migrate via which highway to get to the Olfactory Bulb?
Rostral Migratory Stream https://o.quizlet.com/YAnCjTihuQ3ccO3IPic7ew_m.png
Subarachnoid Haemorrhage (SAH) usually due to
Rupture of berry aneurysm (site of wall weakening)
Higher risk of developing Parkinson's for people living where due to what?
Rural, herbicide or pesticide exposure
Recruitment/Size Principle of motor units
S recruited first during weak contractions, FF recruited when high muscle force required
What are the (3) types of cone photoreceptors? (Not BGR)
S-cones, M-cones and L-cones
Secondary Somatosensory Cortex (S2) have projections to (3+2)
S1, association cortex, motor cortex, amygdala and hippocampus
Which site is phosphorylated in LTP?
S831 (Serine 831)
Transduction mechanism of *salt* (Type 1 Cells)
Salt is NaCl: Na+ influx through *Amiloride*-sensitive sodium channel -> depolarisation of the receptor cell membrane -> More Na and Ca influx ->exocytosis mediated release of *Serotonin* https://o.quizlet.com/TmeP22FY-sADjNYnQDT.ug_m.png
Music Tone
Same as pure tone but characteristicsof timbre or tone colour exist https://o.quizlet.com/2T81Ynu-cGOqGryySlXvJA_m.jpg
*Chroma*/Saturation
Saturation of the signal (how much of the colour/signal is present)
What are (3) key features of LTP?
Saturation, Specificity and Associativity
(2) cochlear compartments are filled with
Scala Tympani and Scala Vestibuli, Perilymph
Cells that do myelination in the PNS and CNS?
Schwann Cells in the PNS, Oligodendrocytes in the CNS
Seeing in poor illuminated areas (night)
Scotopic
Structure of the brain is as much a product of ____ as much as it is a product of growth
Sculpting
Methodological Difficulties in animal experiments
See below
Unwanted depolarisation leads to (2)
Seizures Abnormal brain activity
Secondary Seizures
Seizures are the *result* of cell death, they do not *cause* cell death https://o.quizlet.com/W37khM-UJXumKl1jHozjLw_m.png
Recovery Phase: Secondary
Seizures, decline in function
(3) At term Perinatal Brain Injury types
Selective Neuronal Death Laminar Cell Death Focal Grey Matter lesions (holes) https://o.quizlet.com/IYsu3Dy-u46kE-xvjHa1eQ_m.png
The BBB is known to be a _____ _____ membrane, as there is no _____ barrier in biology
Selectively Permeable, Absolute
What does a low level of calcium influx through NMDA receptors do?
Selectively activates protein phosphatases
What are chemical sensations?
Sensations from interaction of molecules in air and fluid with *chemoreceptors*
Proprioception
Sense of movement and body position
S2 invovled with ___(compound word)__ integration of sensation from
Sensorimotor, sensation from both sides of body
Sensory 2 - Gustation and Olfaction
Sensory 2 - Gustation and Olfaction
Sensory 3 - Auditory 1
Sensory 3 - Auditory 1
Sensory 4 - Auditory 2
Sensory 4 - Auditory 2
Sensory 5 - Vision 1
Sensory 5 - Vision 1
Sensory 6 - Vision 2
Sensory 6 - Vision 2
The tectorial membrane is in close contact with
Sensory Hair cells of the Organ of Corti
What are (3) ways of tract segregation?
Sensory Modality Somatotopic Arrangement Medial-Lateral Rule
The Neural Crest Cells give rise to (6)
Sensory Neurons and Glial Cells Ganglia (a structure containing a number of nerve cell bodies) Cartilage (Face) CT (Face) Adrenal glands Pigmented cells (like dopaminergic cells of the brain and of the skin)
Modality: Transduction
Sensory receptors transform signal (from stimulus) into electrical energy
Which pathways carry information about a single type of stimulus? (3)
Sensory, afferent or ascending pathways
What do current drugs for depression target?
Serotonin and noradrenaline reuptake
Focal Cystic Necrosis is an example of a _____ insult
Severe
Thunderclap headache
Severe and sudden-onset headache
Which (3) aspects of vision does the retina process - what do we see? (Not physics)
Shapes, colours and borders
Which mammal has a very large Olfactory Bulb? Why? (2)
Sheep, used for detecting types of grass and their babies
High frequency stereocilia
Short
BDNF Functions: Can activate (2)
Short Term: CaMKII Long Term: PI-3K, PKA, PKC, CaMKII
S-Cones, maximum sensitivity to
Short-wavelength sensitive, Blue, 440nm https://farm1.staticflickr.com/5/4649941_3878ff663e_m.jpg
Trichromatic Theory: Cone Spectral Sensitivities
Shows that the cones are responsive to a specific range of wavelength https://o.quizlet.com/ltXYII66Hp6HjwsoMfYuEg_m.jpg
[Figure] Functional MRI of the Auditory Cortex
Shows tonotopic organisation https://o.quizlet.com/omYFQ9QQm0n.Wns9AuzzNw_m.png
The inhibitory synapse near the soma of the body activates and hyperpolarises this segment of the dendrite. This electrically shunts (dampens) the excitatory depolarisation arriving from the upstream region of the dentrite is called
Shunting Inhibition https://o.quizlet.com/uITzx3ByJ-ED0izXTZ6WLQ_m.png
Asphyxial insult - we observe what in EEG?
Shut down of brain activity (EEG fluctuations reduced) https://o.quizlet.com/2fpl533pTygaZUK5Pg74Ow_m.png
Intracerebral Haemorrhage (ICH) symptoms (3)
Similar symptoms as Stroke Thunderclap headache Loss of consciousness
H-Reflex (Hoffman)
Similar to Myotatic Reflex but you apply an electrical stimulus instead of hammer
Mononeuropathy and causes
Single Nerve Trauma, infection, loss of blood supply, compression (pins and needles)
Motor skills Non-Declarative Memory
Skills (subconscious) - Cerebellum
Procedural Non-Declarative Memory + Part of Brain Associated
Skills (subconscious) - Striatum
(2) types of adaptation?
Slow Adapting/Tonic Rapidly Adapting/Phasic
S/FF: Contraction Speed
Slow/Fast
Bradykinesia or akinesia
Slowness of movement (computer mouse)
Type II spiral ganglion neurons (Size and myelination)
Small and Unmeylinated
The M Cell receptive field is more sensitive to
Small center-surround brightness differences
Mechanoreceptor Receptive Field
Small for fine sensation - Fingers Larger for crude sensation - Back
Papillae
Small projections scattered about the surface of the tongue. Shaped like ridges, pimples or mushrooms https://o.quizlet.com/xwTke2fG02wzZJ26eBywPw_m.jpg
Small Bushy Ganglion Cells are concerned with processing
Small stationary, fine detail in tonically activated messages
Stage Theory: Blue/Yellow information is conveyed to which cells in the Retina and in the LGN?
Small-Bistratified Ganglion Cells and Koniocellular Nerons https://o.quizlet.com/20RNOEPhB5Tg2H8arfuiVg_m.png
S/FF: Muscle fibres size
Small/Large
S/FF: Size of cell body
Small/Large
S/FF: Tetanic Tension
Small/Large
Small cells are in layers __ and large cells (example) are in layers __
Small: 2 and 4 Large: 3 and 5, Motor Neurons
Accessory olfactory systems detect pheromones to mediate which (2) types of behaviours?
Social and sexual behaviours
Reflexes can be (2)
Somatic (our focus) or Autonomic
What are the (2) types of Gene Therapy?
Somatic and Germline
Name for touch cortex?
Somatosensory Cortex
∆ cortical representation termed? (2)
Somatosensory or Cortical Plasticity
Cerebellum is also organised?
Somatotopically https://o.quizlet.com/hyle1CItLffj8N1kF9XRLA_m.jpg
Activation Thresholds of mechanoreceptors?
Some activate with light touch, some with heavy
What do umami receptors detect?
Some amino acids (protein eg. glutamate and aspartate)
What are some visual adaptations of animals?
Some can detect infrared, some only colours except for red https://o.quizlet.com/0eSaegoLdXswal7H1upXtQ_m.png
However, there is no doubt that memory consolidation requires
Some form of synapse remodelling, and the mechanisms of synapse plasticity fit this requirement
Germline Gene Editing laws internationally differ how?
Some have bans with criminal penalties, some have guidlines
Selective Neuronal Death (define and what structures of brain affected)
Some neurons die off Hippocampus, cortex, striatum
Sound vibrations are filtered along the cochlear partition to produce focused displacement of the basilar membrane at frequency specific regions.
Sound moves through the cochlea and causes movement of hair cells at specific regions (each region is specific to a certain frequency)
How is the intensity of sound distributed when the high frequency sound comes from the *front*?
Sound shadow behind head, equal intensity for both ears https://o.quizlet.com/G4injpDwbLa1KROBaBYh4A_m.png
Type 3 Cells
Sour Taste Innervated directly GABA or serotonin NT here https://o.quizlet.com/YqfIKMCO7pIJcPreGRPffg_m.png
Transduction mechanism of *sour* (Type 3 Cells)
Sour is Acidic: H+ influx through channel or *blocking K+ channel* -> depolarisation of the receptor cell membrane -> More Na and Ca influx -> exocytosis mediated release of *Serotonin* https://o.quizlet.com/i4LjFwYf0KHrvbuKdH8b0w_m.png
Supramarginal/Angular Gyrus function (right)?
Spatial 3D recognition, arty side of the brain
Sense of smell is linked to ______, somewhat for us and more so for redents
Spatial Awareness
Supportive Evidence: Agents that block LTP/LTD also prevent
Spatial learning in rats (eg NMDA receptor blockade)
Most models focus on
Specific aspects of a disease. Aetiology Pathophysiology Symptomatology Response to drugs
How did Tim Bliss and Terje Lomo find LTP 40 years ago?
Specific stimulation of the Perforant Path (1) led to increased strength of the synapses onto Dentate Gyrus Cells (2)
(Choosing the right) Vector Tropism
Specificity of viral vectors targeting a specific cell type
Failure of the posterior end of the neural tube to close is
Spina bifida
Reflexes Golgi Tendon Organ generates? (2)
Spinal Supraspinal
Cerebellum pathway
Spinal Cord → Spinocerebellum → *Interposed Nucleus (Deep Cerebellar Nuclei)* → Thalamus → PMC https://o.quizlet.com/ZrgPCK5QjMW2FLBEqpAuwg_m.jpg
Somites become
Spinal Vertebrae
Where are processing centers found? (4)
Spinal cord, brainstem, thalamus and cerebral cortex https://o.quizlet.com/GxOUlDDcX3dtPRjVKV63xg_m.png
Cerebellum has input from which (3) areas?
Spine, Cerebral cortex and Vestibule (ears)
What are the (3) cerebellum regions based on input?
Spinocerebellum Cerebrocerebellum Vestibuloverebellum https://o.quizlet.com/cEiuk.MiBLvHnHjUNhqixg_m.jpg
What are (5) types of animal models?
Spontaneous Chemical Transgenic Genetically Induced Behaviour Models
Recovery Phase: Latent
Stability - don't observe any problems (Baby may look normal)
The Incus makes a ligamentous connection with the
Stapes
What is the meaning of *Astrocytes*?
Star-looking
Which cells are the candidate regulators of DS ganglion cells?
Starburst Amacrine Cells
Glialblastoma
Start with being fine, 4 months and size of golf ball tumor - fast and aggressive
How do you genetically reprogram cells?
Step 1: Get a Somatic (Skin) Cell (Biopsy) Step 2: Put in *pluripotency inducing genes* Step 3: Cells can form all cells of the body
What are the steps from umbilical cord occlusion → Brain injury?
Step 1: Occlusion of the umbilical cord Step 2: ↓oxygen + glucose delivery to foetus Step 3: Impaired foetal cardiovascular function Step 4: ↓BP + blood flow to brain Step 5: Brain injury results
How does glutamate excitotoxicity as a result of the primary insult cause cell damage and death? (8 steps)
Step 1: PRIMARY INSULT - cerebral energy deficit Step 2: Glutamate transporters cannot re-uptake glutamate from synapse Step 3: Glutamate accumulates at synapse Step 4: Excessive activation of glutamate receptors (LTP) Step 5: RECOVERY PHASE - Cerebral energy levels restored - Glutamates levels at synapse restored Step 6: Glutamate receptors now hypersensitive to glutamate Step 7: Glutamate release causes excessive postsynaptic cell activation (microseizures) Step 8: Excessive Ca influx into postsynaptic cells triggers apoptosis
Apoptosis Mechanism
Step 1: Pre Apoptotic Cell Step 2: Early Apoptotic - Membrane blebs form Step 3: Late Apoptotic - Apoptotic Bodies bud off Step 4: Macrophages/Microglia Clean these up https://o.quizlet.com/vha9UlVswSWBug-hiDUzEQ_m.jpg
Secondary Oxidative Metabolism Failure
Step 1: Something is triggered during the insult OM Failure Step 2: Develops during the latent phase Step 3: Causes mitochondria to start failing Step 4: Failure of OM (second time) Step 5: Cells start dying Apoptosis AND Necrosis
Mechanical Transduction: Detection of vibration by the cochlear, vestibular and lateral line sensory hair cells
Stereocilia on surface of the hair cells, have tiny linkages, at the tip there is a mechanically gated ion channel, when these are bent back in the presence of sound, channels open and close → ion influx → AP https://o.quizlet.com/08dpc-9C7802FuvdQvFw.A_m.png
Deuteranomalous trichromats
Still see all colours, but weaker green https://o.quizlet.com/47Jap1YHhHi6O7mlbEpjpA_m.jpg
Protanomalous trichromats
Still see all colours, but weaker red https://o.quizlet.com/s15qoTyIJYOl-IEOKx2N2w_m.jpg
Neuron replacement or Gene therapy
Stimulate cells in striatum to endogenously repair or produce more GABA etc.
How can we help patients with IHC and OHC loss?
Stimulate nerve endings -> *cochlear implants*, directly stimulating nerves
What may dying cells or astrocytes do in an inflammatory response?
Stimulate the recrutiment of immune cells to help with fighting the bacteria or clearing up the mess
Saturable
Stimulated synapses increase in strength, but only up to a maximum level
Trichromatic Theory: E.g. How is yellow light picked up?
Stimulates L (Red) and M (Green) cones equally but S (Blue) weakly https://o.quizlet.com/LcvB1vlqbhK40BPvpvkUUg_m.jpg
Peripheral Nerve Stimulation and Paired Associative Stimulation (PAS)
Stimulating the peripheral sensory nerve and depolarising the neuron that synapses with this peripheral sensory nerve (in the CNS - *pairing*) 90 times (with 5 second spacings) shows LTP when comparing the corticomotor excitability. Need to be very careful with timing https://o.quizlet.com/BS8VFXODNSh.oD.1r9H5BQ_m.png
What did Tim Bliss and Terje Lomo find?
Stimulation of excitatory synapses of the *Perforant Path* into the hippocampus lead to a long-term increase in synapse strength
Induction
Stimulation protocols induce an increase in synapse strength
Long term depression (LTD)
Stimulation that leads to decreased synaptic strength
Long term potentiation (LTP)
Stimulation that leads to increased synaptic strength
M Cells respond maximally to
Stimuli moving across its receptive field
The P Cell receptive field produces weak responses in response to which type of stimuli?
Stimuli that move across its receptive field
The Intensity (amount) of stimulus (sensation) is determined by
Stimulus amplitude
What does a whole cell recording give us a measure of?
Strength of synapses at an individual neuron
Negative reinforcement
Strengthens behaviour because it stops or removes an unpleasant experience Car beep and seatbelt
What are the (4) reflexes?
Stretch Reflex Reverse (Inverse) Myotatic Reflex Flexion (withdrawal) Reflex Crossed Extension Reflex
Ruffini Corpuscle
Stretch and Distortion of dermis
Where does the latency in the Myotatic Reflex come from? (Each arrow represents time - 7)
Stretch → Receptor AP → Afferent Path → Spinal Cord → Efferent Path → NMJ → Myocyte AP → Excitation-Contraction Coupling
Myotatic Reflex can be evoked by (3) of a muscle
Stretch, vibration or passive extension of a muscle https://o.quizlet.com/9VxWxa9TSw3YsDaPpll-yQ_m.jpg
Which (2) structures form the *lateral wall* of the cochlea?
Stria Vascularis and Spiral Ligament
The endocochlear potential depends on an active secretion of K+ by the (2)
Stria vascularis and *Fibrocytes* of the spiral ligament
Second Pathway to Degenerate
Striatum to Substantia Nigra (Striato-nigral Neurons)
Injury to thalamus is usually due to a
Stroke
Upregulation of *ICAM-1 (CD106)* and *VCAM-1 (CD54)* causes
Strong interaction with blood leukocytes
The cells that travel up the radial fibers are
Structurally and Functionally Immature
Where are these viral vectors targeted?
Substantia Nigra/Striatum or both
Glutamate excitotoxicity can cause
Sudden Deafness
Transient Ischemic Attack (TIA)
Sudden onset of focal neurological symptoms <24 Hours No infarction
A stroke is recognised by
Sudden onset of focal neurological symptoms Persists for >24h.
Trichromatic Theory: This theory is based on what?
Suggests that a combination of three channels (colours) can yield all colours of the visible spectrum
Knock-in Huntington's Mice: Experiment
Supplementation of BDNF and *EPSP's* recorded at *CA1 region* after *Schaeffer collateral* stimulation
Type 1 cells
Supporting Cells, Salty Taste No Neural connections Might take up glutamate https://o.quizlet.com/i3XIrcrc6eN5L6OdcORMVA_m.png
What are the hair cells surrounded by?
Supporting cells that provide structural and metabolic support
Could synapse plasticity underlie memory?
Supportive Evidence follows
Delivering low frequency stimulation will
Suppress excitability - LTD *like*
Patterned theta burst stimulation: Continuous
Suppresses excitability (LTD-like) https://o.quizlet.com/J1VaHeQWEUYFSZ2x9G8dnA_m.png
Reflexes Neuromuscular Spindle generates? (1)
Supraspinal
When we look at an object, we are actually seeing its
Surface Reflectance
LTD results in a decrease in
Surface synaptic AMPA receptors
Slow Adapting/Tonic (+ sensation example)
Sustain response, slow to return Touch, pressure
S Type motor units are best suited for carrying
Sustained but small loads
Type 2 cells
Sweet, bitter and umami Pseudo-innervation by Gustatory https://o.quizlet.com/.gyAj50psWLx-3aq92sB7Q_m.png
Type II: Inhibitory synapses are also called
Symmetric
Proposed treatment targets?
Symptoms Push remaining function neurons (but they die progressively)
In which (3) ways can we determine what part of the brain the disease is affecting, and how it is affecting it?
Symptoms (e.g. smell means olfactory bulb) Post Mortem Material (Degeneration/inflammation) Genetic Mutations
LTD is thought to underlie the synaptic weakening that occurs before
Synapse elimination (but this has not been directly shown)
What (2) things need to happen simultaneously for LTP to be induced?
Synapses must be active and Postsynaptic cell must be depolarised (associativity)
Difficulties: LTP can only be measured at a subset of
Synapses, and these may *not* be the same synapses that are being modified during the learning task
Physical embodiment of memory occurs via which cellular process?
Synaptic Plasticity
What allows the postsynaptic synapse to be repaired?
Synaptic Plasticity
Although IHCs are quite resistant to noise, the noise mostly affects the
Synaptic region of the IHCs, causing swelling of neurons
Long Term Potentiation (LTP) is an increase in
Synpatic Strength
Tonotopy
Systematic organization of *characteristic frequencies* along the basilar membrane
Smell and taste complement each other but
Systems are separate except at highest levels in the brain
Receptors used in amino acids (umami)
T1R receptors
Receptors used in sweetness
T1R receptors
Which T1R receptors are needed to detect amino acids (umami)?
T1R1 and T1R3 https://o.quizlet.com/Zts3YdRY0yhhMHvXQ5A3lA_m.png
Which T1R receptors are needed to detect sweet compounds?
T1R2 and T1R3 https://o.quizlet.com/7b4tQqs9U0BgFKoZSI.bNg_m.png
Receptors used in bitterness
T2R receptors https://o.quizlet.com/wISyV7oNZ5-rNuv18cDFyQ_m.png
Which (2) enzymes are part of the endogenous biosynthesis of dopamine?
TH (Tyrosine Hydroxylase) and AADC (L-Amino Acid Decarboxylase)
What are the (2) TRPs?
TRP *M8* (Cold) TRP *V3/4* (Warm)
What type of receptors (biological) do thermoreceptors utilise?
TRP - Transient Receptor Potential Channels
Why projections to amygdala and hippocampus?
Tactile learning and memory
Benefits of Cell reprogramming?
Take skin cells or diseased cells from patients and study them (try out drugs, etc) and/or after fixing them put them back in
What is the problem with this method?
Takes too long to go from skin → Pluripotent → Multipotent → Neuron
What is the problem with this method this time?
Takes you to a neuron (doesn't give rise to anything else) so after you do experiments on them, they are useless
Cells in the Rostral Migratory Stream migrate by which mechanism?
Tangential Migration, use one another as a scaffold
What happens if you co-culture astrocytes and neuronal cells, and kill either/or off?
Target and destroy *astrocytes*, neurons will be out in about 24-48 hours Target and destroy *neurons*, not much effect on astrocytes
What would be the function of a drug used to treat, for example, MS? (3 Examples)
Targeting anything that recruits the immune cells. Interfere with the way: (1) Cells attach to the vasculature (Reduce CAM) (2) Immune cells respond to the inflammatory signals such as cytokines (reduce the sensitivity to interleukin-1 and Tnfα) https://o.quizlet.com/q0liDf1NRuFVgCdg-6bWnQ_m.png
What are the (2) chemical senses?
Taste (gustation) and Smell (olfaction)
Taste buds are a collection of
Taste Receptors
What covers the Organ of Corti?
Tectorial Membrane https://o.quizlet.com/FlN1GBxR4FGKm7kOwem1LA_m.jpg
What are the two subdivisions of the prosencephalon after the three vesicle stage?
Telencephalon and Diencephalon
The Prosencephalon divides into the (2) by the __ vesicle stage.
Telencephalon, Diencephalon, by the 5 vesicle
The audtory cortex is located in the
Temporal Lobe
Noise Trauma (loud sounds) can cause which (2) types of hearing loss?
Temporary or Permanent Hearing Loss
Golgi Tendon Organ monitors
Tension, pressure and joint movement https://o.quizlet.com/JuEw6t2i64mFrB50iIbQSQ_m.jpg
What are the (2) smallest in the body muscles in the ear?
Tensor Tympani and Stapedius
Who discovered LTP?
Terje Lomo (1966, Oslo, Norway)
Experiment: Fetal responses to maintain brain perfusion during asphyxia - Logistics?
Term fetal sheep Complete UCO (Umbilical Cord Occlusion) for 10 min ↓oxygen/energy supply to foetus (asphyxia) https://o.quizlet.com/xy5Rckq8LF5A9ER9heg60g_m.png
(3) Reorganisation Phase
Tertiary (Weeks+) The appearance of apoptosis Cells die → neighbouring cells lose support → they die → chain of events
Ishihara Test
Tests our ability to distinguish between the red, green and blue
What type of stimulation to only the presynaptic cell did Bliss and Lomo induce LTP with?
Tetanic Stimulation
Axons from the inferior colliculus lead to the? (Be specific)
Thalamus - Medial Geniculate Nucleus
Retina Projection: Lateral Geniculate Nucleus
Thalamus - the major subcortical centre relaying visual information to the *primary visual cortex*
What did Thomas Young (1802) propose?
That perception of colour can be coded by three *principal colour receptors* rather than thousands of colour receptors coding for individual colours
Although Neurturin failed, what has this and placebo trials showed us?
That the human brain *tolerates* viral vectors quite well and that the *procedure is safe*
What determines whether LTP or LTD is induced?
The *level/rate* of calcium influx through NMDA receptors
Where does the information travel after the Nucleus of the solitary tract (Gustatory nucleus)?
The *ventral posterior medial nucleus* of the thalamus and then to the gustatory cortex https://o.quizlet.com/wD-9u8hD.vFIAnxv8gN1qQ_m.jpg
What is the N1 (first peak) in the Electrocochleography recording?
The AP in the above card (Individual Unitary Potentials)
Volley Principle (Phase locking, not on every cycle and Tonotopy)
The APs are fired at a constant location, but will skip a few wavelengths (e.g. every 5 wavelengths). *1kHz - 4kHz* https://o.quizlet.com/6Kl2qjyOUZs.L3BNdWhgtw_m.png
Phase Locking (on every cycle)
The APs fired by the auditory nerve correspond to the frequency of sound (i.e. one AP per wavelength). Easy to determine the sound frequency (same as AP frequency) *<1kHz* https://o.quizlet.com/4lb3ha2q4.W3pMve8a863A_m.png
Where do projections from the thalamus lead to?
The Auditory Cortex
When we hear sound and the cochlear fluid moves, what moves along with it (2)?
The Basilar membrane and thus the Organ of Corti (moves up and down)
What was one of the first targets for AD treatment?
The Cholinergic System
The taste sensations propagate along which nerve?
The Facial Nerve (7th)
Which cells send photo information to the brain?
The Ganglion Cells
Stage 3: What happens now that the organ of corti is moving more vigorously?
The IHCs will come into contact with the Tectorial Membrane
What is the columnar organisation of the auditory cortex known as?
The Ice Cube Model https://o.quizlet.com/HcNP559ZnDHKE-un4aG8Aw_m.jpg
What determines whether Paracellular or Transcellular is used by the leukocytes?
The Inflammatory Environment and the Cells Migrating
What happens after the Reperfusion phase?
The Latent Phase - Post Asphyxial Hypoperfusion https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
What is attached to the tympanic membrane?
The Malleus which forms a ligamentous connection to the Incus
The Rostral Migratory Stream supplies which Olfactory layer with neurons?
The Olfactory Granule Layer
What happens during Inhibition?
The Organ of Corti moves *down*, and the shear force between the tectorial membrane and the stereocilia causes the stereocilia to move in the *inhibitory direction* (towards the *spiral ganglion*) -> closes transduction channels and *hyperpolarises* these cells https://o.quizlet.com/kqOnf4MZ8SESdUcfl9qUKw_m.png
What happens during Excitation?
The Organ of Corti moves *up*, and the shear force between the tectorial membrane and the stereocilia causes the stereocilia to move in the *excitatory direction* (towards the *lateral wall*) -> opens transduction channels and *depolarises* these cells https://o.quizlet.com/BSuifRQPkpUw1M1DK4Lh7w_m.png
What are the (2) openings to the cochlea?
The Round and Oval Windows
What is synaptic plasticity?
The ability of synapses to change their strength in response to specific neuronal stimulation
Perception (L5)
The ability to gain knowledge through the senses
What is a specialised function of Astrocytes?
The ability to provide a crucial support network for neuronal cells (neurotransmitter levels, nutrient supply, waste removal etc.)
The first processing of sound information is at the level of
The afferent axons of the auditory nerve (from the hair cells)
Somatosensory receptors can give information about (3)
The beginning and end of the stimulus The duration of the stimulus The intensity (some are activated with more intensity etc) https://o.quizlet.com/JUPIdZ7YNCIksC540rnBDg_m.png
What are Ganglion Receptive Fields?
The bipolar cells and ganglion cells are organised in such a way that each cell responds to a small circular patch of photoreceptors https://o.quizlet.com/.rx9UTskV5d1Q86x03ULtQ_m.png
Why do we have more gyri in Polymicrogyria?
The brain has to form new folds to accommodate for the surplus of cells
So what does brain actively increasing SNA to decrease CBF show?
The brain's attempt to minimise microseizures
Pinna
The cartilage of the outer ear, diffracts and focuses sound waves https://o.quizlet.com/i/PZ-K5RVnsaEeuyUPlS_ePA_m.jpg
Nuclear Translocation/Nucleokinesis
The cell extends a leading process in the direction of migration, then moves the nucleus through the elongated process to its destination https://o.quizlet.com/sCDvag30Jz47PNT68T4dDA_m.png
What are (2) problems in microglial therapeutic approaches?
The cells are functionally heterogeneous - they are different but similar, so hard to target a specific subset Drugs need to be able to get across the BBB
What is the *mechanism* by which the neurons move? like actually explain how tf they move g
The cells extend leading processes, wrap it around the Glial Cell Fibers and take guidance from the Radial Glial Cells as to which way they should travel
Vestibule
The centre of the osseous labyrinth
Telencephalon
The cerebral hemispheres
What happened in the Phase 2 Trials?
The company providing the GDNF took over from the University research, changed the dosage, administration method and did the trial for 6 months.
(8) Neuronal Death
The death of neurons that are not needed
(1) Neural Proliferation
The dense proliferation of neurons in the *Ventricular/Subventricular Zone* of the prosencephalon. https://o.quizlet.com/o5anJxAKGeqUrSyCaz9Lzg_m.png
Interaural Time Delay (Governed by 2)
The difference in the time of sound arrival at both ears, governed by the (1) speed of sound and (2) the distance between the ears
Emotional Non-Declarative Memory
The emotions you associate with thing - Amygdala
Which cells control the decision of whether the leukocytes will pass, stick or infiltrate?
The endothelial cells or the leukocytes
Concha
The entry into the ear canal, a resonator https://o.quizlet.com/ASLqsaZwuy7rFSrGO2AHMQ_m.jpg
The smaller the receptive field
The finer the touch you can sense
(5) Dendritic Growth
The formation of the incoming information processes
[Diagram] Responses of a single olfactory receptor neuron to odorant concentration
The frequency and number in each panel of action potentials increases as the odorant concentration increases https://o.quizlet.com/xBCCbqQoLNGuTNus6J8fNA_m.jpg
Characteristic Frequency
The frequency at which a *specific* hair cell/afferent neuron has the highest firing rate (e.g. You play a 1500Hz sound at a constant intensity. Hair cell #25 has highest firing rate compared to the other hair cells along the basilar membrane) https://o.quizlet.com/zfV1Pk7TIR8EVX0SWGVhuA_m.jpg
What did Pasko Rakic say?
The function of a neuron is determined by its postion. Its position is determined by its time of birth.
(4) Axonal Growth
The growth of the outgoing information process https://o.quizlet.com/2HFVUCcy-GExuzrFaXajiQ_m.png
Perception Limit
The highest intensity we can hear (of a particular frequency)
Why do we observe ↓Brain Activity?
The initial insult triggers brain to ↑SNA → Vasoconstriction and ↓CBF. As a protective response, the brain ↓activity with ↓CBF https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
In multisensory integration, what happens if the stimuli are strong?
The integration may be weaker
When focusing on a characteristic frequency for a certain hair cell (i.e. 1500Hz), what affects the firing rate?
The intensity (volume)
The neurons from the Superior Olivary Complex pass through what and lead to what?
The lateral lemniscus -> Inferior Colliculus (midbrain)
The Black Box Analogy: Input
The light source
(6) Synaptogenesis
The linking together of the billions of the neruons of the brain https://o.quizlet.com/Gk.dZu2xNJnza12GEqrZWA_m.png
Threshold
The lowest intensity we can hear (of a particular frequency)
(2) Neural Migration
The movement of neurons up the Radial Glial Fibres to form the Cerebral Hemispheres https://o.quizlet.com/dBZT7uO1kr1..twYGTJsuA_m.png
Attenuation Reflex is correlated with?
The muscles contracting in the ear
Waterfall effect
The neurons processing the movement (waterfall - flow of water) are saturated, so when you look away it takes a bit for them to get unsaturated
The amplitude (and therefore intensity) is coded by
The number of neurons activated and frequency (rate) of neural impulses (Strong relation between number of impulses of neural outflow and intensity of stimulus) https://o.quizlet.com/quqgNa2MX7HOX8ccg8ZPcg_m.png
Cochlea
The organ of hearing, fluid filled, deeply imbedded in the temporal pole (difficult to access)
Why does the principal of Interaural Time Delay not work well for High Frequency Sound?
The phase/frequency is too high - time delay cannot be recognised
Essentially, NMDA receptor activation requires depolarisation of (2)
The presynaptic terminal (glutamate release) *and* depolarisation of the postsynaptic terminal (Mg2+ release) (you can think of NMDA as an enhancer of the signal)
(7) Myelination
The process by which Glial Cells wrap them selves around axons https://o.quizlet.com/e9-.9zCZJGlXafE59bCRNw_m.png
[1] Gastrulation
The process of *proliferation* of ICM (epiblast) and *migration* to different regions, forming the primary *germ layers*
Postsynaptic Receptors
The receptors that *bind the neurotransmitter* and usually elicit *channel opening* leading to subsequent *depolarisation* as the initiation of an *action potential*
What is the postsynaptic current flow measured with?
The recording electrode
[Diagram] MS Lesions
The red arrows show lesions, had about 6-7 lesions, largest being about 9-10mm in diameter. Within these the oligodendrocytes are gone, and in the active lesions there are huge numbers of immune cells *expressing CD2* https://o.quizlet.com/Z-hX4z7bwO2ZL7ysWuqBIg_m.png
Pupillary Light Reflex
The reflex that controls the diameter of the pupil in response to varying intensities of light
What is the taste pore?
The sensitive part at apex of a taste bud
What force opens transduction channels?
The shearing force between the stereocilia of the sensory cells and the tectorial membrane
Presynaptic Active Zone
The site of neurotransmitter release
(3) Cellular Differentiation
The stem cell neuron that travels up the radial fiber becomes a more *restricted potential cell* https://o.quizlet.com/NKQ6m782ccrmR2GlLakKbA_m.png
What does a field recording give a measure of?
The strength of synapses from a *population* of neurons
What is special about the efferent IHC synapse?
The synapse is not between the neuron and the IHC, but between the neuron and the afferent neuron https://o.quizlet.com/44wpIUlPOkUFtnu5UGT.CQ_m.jpg
The right part of the visual field is projected onto which part of the retina? (assuming left eye)
The temporal part (left) https://o.quizlet.com/qNyP2vPev1SHpqNsnSZESw_m.png
Diencephalon
The thalamus
Horizontal Sound Localisation depends on
The time of arrival of the sound in both ears
Hair cell stereocilia are the site of mechano-transduction, which is
The translation of the sound vibration into a bio-electrical message to the brain
How does the Farnsworth Panel D-15 work?
The type of colour vision defect can be detected from their arrangement of the caps https://o.quizlet.com/VkBlQBpfF26BJ3h.bN1IKQ_m.jpg
Bony Labyrinth (inner ear) is made up of the (3)
The vestibule, semicircular canals, and cochlea
Potentiation
The*increase in strength of nerve impulses* along pathways which have been used previously, either short-term or long-term
What are synapses highly regulated by? What is a term for this?
Their own activity - plasticity
Why do we have our photosensitive cells at the back?
Theory - protective mechanism, to filter light
What is gene therapy?
Therapeutic genes deliberately inserted into patient's DNA
Ganglion cell receptive fields
There are ganglion cells that are connected with bipolar and certain photoreceptor cells - the bipolar cells are told what the photoreceptor cells are seeing
Localisation of sound in the vertical plane
There is a *direct* sound the goes into the ear canal and a *reflected* sound from parts of the ear pinna. The delay between the direct and reflected sounds change as sound moves up and down. https://o.quizlet.com/JLyXtV0CuoVEECwk4ftoGw_m.jpg
Fallibility of Memory - List of sweet words
There is a common emotion associated with *sweet* and the list of words. After reading the list, the emotion is recalled and you recall other words linked to that emotion → sweet
Why is inflammation of the brain not good?
There is a skull so inflammation will cause a buildup of pressure/fluids
Spikeless mode
There is no AP, where the membrane potential and synaptic transmission is continuous and graded
What have these studies shown in terms of in vivo and in vitro?
These studies have shown that LTP and LTD in vivo have the same properties as in slices
In MS, what happens to the oligodendrocytes?
They are attacked by the patient's immune system
What happens if neurons and corresponding synapses are not used?
They are lost
What is the problem with cell culture models?
They are not neurons (they are cancer cells) and often not even from humans
What is special about the notochord growth factors?
They are the *first* growth factors that help induce cells to differentiate
What does The Commission International de L'Eclairage (CIE) do? (2)
They assign the names to colours Everything about illumination
Stage 2: How do the OHC react to depolarisation? (By how much?)
They contract, due to the motor protein (*Prestin*) in the lateral membrane - shortens the cell by *2-3µm* -> cochlear amplification of the sound https://o.quizlet.com/zeCictkvduOqm4XIEBJNiA_m.jpg
Why are inhibitory synapses important?
They control/regulate the excitability of neuronal circuits
What happens to the Neural Crests once the Neural Tube is formed?
They drop to the lateral (superior) margins of the Neural Tube, beneath the ectoderm (like small mickey mouse ears)
Why are auditory sensory cells called hair cells?
They have a tuft of stereocilia
What happens if there are no signals for the leukocytes?
They will bugger off in the blood
Trichromatic Theory: Was explored by who?
Thomas Young and Helmholtz in 1802/1866 respectively
Basal Ganglia Connections: We focus on?
Three Pathways numbered by order of degeneration
When the Prosencephalon, Mesencephalon and Rhombencephalon are of equal size, this is refered to as the
Three Vesicle Stage
Semicircular Canals
Three fluid-filled bony channels in the inner ear. They are situated at right angles to each other and provide information about orientation to the brain to help maintain balance
How many fluid filled compartments are there in the cochlea?
Three https://o.quizlet.com/ERaW97.uUy3fHB3KONn5PQ_m.png
How many gustatory neural pathways lead up to the brain?
Three https://o.quizlet.com/Qochq7V9pdUBoye6eEgcWw_m.png
Stria Vascularis
Three rows of epithelial cells lining the scala media
Stage 2: What is the arrangement of hair cells?
Three rows, graded (short to long) https://o.quizlet.com/0LGgN.npBYmjJ.TOQaqXgg_m.jpg
Rods process (1)
Thresholds/intensities
Thrombolysis
Thrombolytic agents ("clot-busters") lyse thrombus (do this early)
2. Embolism.
Thrombus in heart → breaks loose into circulation, → lodge in artery in brain → block blood flow.
Thrombus and Embolus
Thrombus: Blood clot impeding blood flow Embolus: Moving in circulation
DSGCs are located
Throughout the retina
Subarachnoid Haemorrhage (SAH) Symptoms (3)
Thunderclap headache Vomiting Loss of Consciousness
At the cell junction cleft, which junctions are more apical and more basolateral?
Tight Junctions more apical Adherens Junctions more basolateral
Which (2) junctions are in high concentration in the BBB compared to the rest of the body?
Tight and Adherens Junctions
Endothelial cells in the BBB have a very high density of
Tight junctions
Stage 2: Stereocilia on hair cells are linked by (2)
Tip Links and Lateral Links (all stereocilia move in unison)
Flexion (withdrawal) Reflex Synaptic Relay
To *excitatory interneurons* → excite flexor αMNs at differnt spinal segments
What is the Tensor Tympani and Stapedius muscles' roles? How?
To attenuate loud sound - they contract and cause the Ossicular Chain to become more rigid
What is the function of Astrocytes in relation to the BBB?
To control, regulate and maintain the blood brain barrier - without astrocytes the BBB is not able to maintain the level of biointegritiy it has
Three person babies and Germline Gene Therapy?
To correct mitochondrial disease Paternal Sperm + Maternal Egg Nucleus + Third Party Maternal enucleated Egg
How else can TMS be used?
To deliver low and high frequency trains of stimuli to the motor cortex
External ear sound localisation
To determine sound direction
What are some auditory adaptations of animals?
To improve range and localisation (Hearing organs on the knees of crickets) https://o.quizlet.com/95NlYgIvyaUW33Med2zbYg_m.png
Why do we have gyri?
To increase SA in the brain
In vivo Gene Delivery
To insert pathogenic gene into model organism to induce disease e.g. CAG repeat in HD, α-synuclein/parkin in PD
Why are electrophysiology setups covered by a faraday cage?
To isolate the neurons from electrical noise (lights etc)
What is immunotherapy?
To mobilise body to attack Aß with its own immune system
Why is there a necessity to exercise?
To prevent atrophy of FF Units
Diagnosis of Parkinson's Disease: When would imaging be required?
To rule out other diseases that resemble Parkinson's disease
What is the potential of GDNF?
To stop the loss of and even causing the sprouting of new dopaminergic fibers
Where else do inferior colliculus axons lead to?
To the Superior Olivary Complex, where the visual and auditory information converges
The shunting inhibition prevents current flow
To the axon hillock and further spread of excitation
How is Conditional Expression used?
To turn on expression only during development, for example
How else can Gene Therapy be used?
To understand Disease Pathology
Why do we need good disease models?
To understand pathophysiology
Where are sensory receptors for taste found?
Tongue
Receptive field of auditory receptors is called
Tonotopicity
The hearing loss pathway
Too much sound -> overstimulate IHCs -> excessive glutamate release -> NMDA receptors become too much permeable to Ca -> Swelling -> Apoptotic Pathway -> destruction of postsynaptic spiral ganglion neuron https://o.quizlet.com/fnsi-qgmWqzrh363snezew_m.jpg
Reverse (Inverse) Myotatic Reflex function?
Too much tension in tendon of muscle causes muscle to relax and drop object (Arm wrestle) https://o.quizlet.com/u09si9RnJBDN.ARqFCm7qA_m.jpg
How many taste buds in the mouth?
Total of 2000-5000 taste buds in tongue
What is the Somatosensory Homunculus?
Touch representation in somatosensory cortex https://o.quizlet.com/xAw5yttuskObZWfjwZff.Q_m.png
How does Age Related Hearing Loss progress?
Towards the lower frequencies, which are important for speech understanding
What are (2) causes of Lissencephaly?
Toxin/Toxic or Genetic
What is the mechanism of Tangential Migration?
Trailing edge of one cell is wrapped around the leading edge of another cell, work via guidance
What are (4) aspects of Modality encoded in specific neural response?
Transduction Receptor Potential Receptor Specificity Labelled Line
Transgenic vs. Gene Therapy
Transgenic: Before Birth Gene Therapy: After Birth, but if germline then ambiguous
Transient Ischemic Attack (TIA) are due to
Transient lack of blood supply
Rapidly Adapting/Phasic (+ sensation example)
Transient response, quick to return Texture and vibration
What happens during the primary asphyxial insult (e.g. umbilical cord occlusion)?
Transient ↓HR, ↓Brain Activity, ↓CBF https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
M Cells respond with what kind of response to which type of stimulus?
Transient, rapidly adapting response; maintained stimulus
C (IV) Fibres (Velocity and to where)?
Transmit slow pain to *Affective-Motivational Area*, and some PSC (Non-discriminative)
Cornea
Transparent layer at the front of the eye https://o.quizlet.com/i/uFz1rgQiOSooJmMTJBtsDw_m.jpg
What causes Peripheral Nerve Somatosensory Injury?
Trauma, infection, ischemia, disease (diabetes) Axon dieback, demyelination, nerve cell death
Spinal Cord Somatosensory Injury. Causes?
Trauma, infection, swelling, damage to blood supply
What was the result this time?
Trial stopped due to lack of efficacy and possible cerebellum lesions as a result of GDNF in monkey trials.
What are the (3) theories of Colour Vision?
Trichromatic Theory Opponent Colour Theory Stage Theory
People with normal colour vision are called?
Trichromats https://o.quizlet.com/N3.S4DOQIwSAdPdRu1dewA_m.jpg
Absorption of light by three different spectral classes of cones is known as
Trivariant
If someone has a neurodegenerative disease, and their cells are expressing CB2, what do we do?
Try and reduce the exacerbation of the disease once it has kicked off
By examining pathophysiology of depression at cellular/molecular level, what can we do next?
Try out novel drugs and look for proof of concept
Gene editing of human embryos in China?
Trying to fix fatal blood disorder from non-viable embryos (i.e. ones that cannot result in live births)
Pillar Cells form the
Tunnel of Corti
There is a constant turnover of
Turnover of taste cells, ~2 week lifespan
One AP causes a
Twitch
Organ of Corti contains
Two types of sensory hair cells and supporting cells
The ear canal (and external ear) ends at the
Tympanic Membrane/Ear Drum, a thin diaphragm about 9mm in diameter https://o.quizlet.com/nxlr-rQx2vtglgIahnXslg_m.jpg
What are the (2) types of spiral ganglion neurons?
Type I and Type II https://o.quizlet.com/u-025mFSXE9CVk4Dehb7kA_m.jpg
Flexion (withdrawal) Reflex Afferent
Type III and IV Fibres https://o.quizlet.com/j1zNTEQuAA4IX1m6S.2Piw_m.jpg
Paternal Inheritance of CAG repeats
Typically (-1 → +7) change from paternal repeat number
Pathway of Dopamine production in vivo?
Tyrosine (Tyrosine Hydroxylase) -> L Dopa (DOPA decarboxylase) -> Dopamine
Threshold of Reverse (Inverse) Myotatic Reflex is higher in
UMN disease - Clasp knife reflex
Spinocerebellar Tracts
Unconscious proprioceptive information → Cerebellum for muscle contraction control
Receptor density is not
Uniform throughout sensory organ
Non-Declarative: Short Term located
Unknown
These increases in size and number of synapses are
Unlikely to underlie the *immediate increase* in synapse strength seen with LTP
Saturability of LTP
Upon further trains of stimulation, the synaptic response increased but stopped eventually at a maximum level
Olfactory Receptors are localised in the
Upper nasal cavity https://o.quizlet.com/Cs4CtcVHt3-0bNAGwzm5qQ_m.jpg
Where is the olfactory bulb found?
Upper part of nose https://o.quizlet.com/MviNxzAE13zDQRq1kAM0Mw_m.jpg
(4) Match cellular metabolic activity (demand) to energy supply
Use EEG to measure brain activity when giving an asphyxial insult
How do you solve this problem?
Use another set of genes (Sox2 / Pax6 and / or Neural reprogramming media) to go from skin cells → Neural Precursor Cell - use these to make different neurons
What can we do for treatment?
Use drugs (*Cholinesterase inhibitors*) to inhibit *ACh esterase* to maintain ↑[ACh] at synpases
How can we inhibit microseizures?
Use glutamate antagonists to bind to NMDA receptors → ↓Microseizures → ↓Brain injury
Short-term/Working Memory example?
Used to achieve a short term goal You come up to lights, they turn green, you remember for 5 seconds that it was green and you go
Anticholinergic agents
Usefor for tremor treatment
Opponent Colour Theory: How was this theory created?
Using *hue cancellation* experiments, colour opponent channels were isolated through the use of subjects (humans)
Transduction mechanisms: Photoreceptors
Utilise intracellular *second messenger* systems
Transduction mechanisms: Chemical stimuli utilise inotropic/metabotropic?
Utilise intracellular *second messenger* systems or sense chemical directly (eg salt on tongue)
MRI Scanning
Utilising magnetic spin of H to visualise brain
What is the stereocilia arrangement in the OHCs?
V Shaped https://o.quizlet.com/8lqo4vSTYsOQnrME.-UeOg_m.jpg
What are the motion perception areas in the brain? (6)
V1, V2, V3, V4, V5 (V5 also known as Medial Temporal Area) and *Posterior Parietal Cortex*
Vomeronasal organ has which genes?
V1R and V2R
What part of the thalamus receives information from those pathways?
VPN - Ventral Posterolateral Nucleus
Which part of thalamus affected?
VPN damage → Loss of all somatosensory
What is the nociceptive receptor?
VR-1
What are (3) therapeutics used to slow AD progression?
Vaccines, Secretase inhibitors and anti-aggregants
The BBB is highly what? Why?
Vascularised Vascularised Vascularised, neurons rely on glucose
What are (3) ways we can modify viral vectors?
Vector Tropism, Gene Promoters and Conditional Expression
The Auditory Nerve branches and innervates which (2) structures?
Ventral and Dorsal Cochlear Nuclei https://o.quizlet.com/APpMzD8ELzXNmAfwIYfcIQ_m.jpg
2. Posterior circulation
Vertebral arteries and basilar artery provide blood to: Brain stem, cerebellum, thalamus, medial part of the temporal lobes and the occipital lobes.
Adeno-associated Virus (AAV)
Very Small Enters cells easily
What do we see when we compare MS lesion tissue with non-MS lesion tissue?
Very different cellular morphologies observed in different lesions and within lesions. Blood vessels and capillaries are often *CB2 positive* https://o.quizlet.com/IN1klgcc4TEqrN4IaJNi3A_m.png
Rods allow us to detect
Very low levels of light (lower threshold to light) - night vision only, black and white
At *low* concentrations of stimulus (specific taste) most papillae are
Very selective
The Ca2+ influx elicits
Vesicle fusion, resulting in neurotransmitter release
Which (4) other Modalities can we add?
Vestibular (balance and acceleration?) Additional somatosensory (pain, temperature, itch and proprioception) Electrosensory Magnetic
Name for balance cortex?
Vestibular Cortex
What happens during a complex sound?
Vibration of the basilar membrane at several regions -> converted into receptor potentials -> send to brain -> processed and analysed there!
Damage to Primary Somatosensory Cortex leads to total loss of
Vibration, proprioception, discriminative touch
Normal Virus vs Viral Vector Virus?
Viral Vector has *viral genes* (gag-pro-pol) replaced with *transgene*. Cannot replicate but can still infect cell
Infections
Viral infections cause illnesses similar to PD Von Economo's and Japanese encephalitis Influenza A virus- infection of substantia nigra
The colours we see are part of the
Visible Colour Spectrum
What are the (5) major classic modalities?
Vision, Hearing, Taste, Smell and Touch
Somatosensory System excludes
Vison and Hearing
Name for seeing cortex?
Visual Cortex
The Motion Aftereffect (MAE)
Visual Illusion experienced after viewing a moving visual stimulus and then fixating on a stationary stimulus
Somatosensory Association Cortex has input from (different modality)
Visual areas
What happens when IHCs are depolarised by K+ influx?
Voltage Gated Ca Channels open (Ca Influx) -> Exocytosis of NT from synaptic vesicles https://o.quizlet.com/R39iUew.ZeD1Z94r6VxQjA_m.jpg
Forebrain is for what type of movements? (1)
Voluntary
What are (2) types of temperature responses?
Voluntary and Autonomic
What are the (3) Classes of Movements?
Voluntary, Reflexes and Rhythmic Motor Patterns
What is the special sense organ?
Vomeronasal Organ (VNO)
Name of scale to gauge HD progression?
Vonsattel Grading Scale
What type of injury is possible in at term perinatal brain injury?
WMI: Cystic and diffuse damage possible
Cones process (2)
Wavelengths and thresholds/intensities (which is why we can see colour with cones)
What is the meaning of adapting to stimuli?
We adapt to the clothes we are wearing or the seat we are sitting on etc.
Why are Microglial cells an interesting therapeutic target?
We can generate a vast repertoire of cytokines to influence the level of phagocytosis
What does this ~100x decrease represent?
We can see a lot, but it has been summarised down to send compact information to the brain
Why can't we make good drugs? (2)
We can't trial on humans and animal models aren't humans Post mortem brain lacks tissue we want to study
What happens in illusions?
We over saturate a group of *MT/V5 neurons* in our brain
When picking up, i.e. an egg, what happens?
We sense the weight and fragileness of it in our hands, so a *feedback system* allows fine control (not squashing the egg in our hand)
What is the benefit of weak contractions over strong ones?
Weak can be can be graded with greater precision
LTP lasts how long?
Weeks, months - up to 2 years (record)
Declarative: Long Term located
Wernicke's for meaning of words, temporal cortex for memories of objects and faces etc.
Visual Field
What you can see at a given time (constraints are the anatomical borders, like the nose)
When can current flow be measured through the NMDA-type glutamate receptor?
When the postsynaptic cell is depolarised to positive potentials (Mg is released) https://o.quizlet.com/.NYRfoEiJ9fPkG3JT0GyfA_m.png
Supportive Evidence: When does LTP reverse in rats?
When they explore a novel environment, reflecting the dynamic, plastic nature of memory
When else is the Attenuation Reflex activated?
When we speak, so we hear quieter than we actually sound
How do they complement each other (2 example)?
When you have a cold, you can't smell or taste food as well (becomes bland) When you have coffee, the smell aroma might be nice, but the taste can be bitter
Opponent Colour Theory: Hue Cancellation Experiment
When you keep adding the opponent colour, there is a transition seen but there is never a mix of the two opponent colours - another colour forms instead https://o.quizlet.com/aREYaVZZTOJbsokQfFZR6Q_m.jpg
Episodic Declarative Memory
When you recall an event and express it via combination
Chemical Animal Model
Where a chemical is used to induce the disease in an animal e.g. 6OHDA/MPTP for PD and QA for HD
Spontaneous Animal Model
Where the animal spontaneously acquires a disease e.g. Batten's Disease
Stage Theory: Neural Processing
Where the colour opponency occurs (in the *horizontal cells* in the retina *and* continues in the brain) https://o.quizlet.com/MeS1Irxpz43RTQ6rUwgMeQ_m.png
Transgenic/Genetically Induced Animal Model
Where there is a gene knockin/knockout to induce disease in an animal e.g. Increase HD repeat length
The height of stereocilia depends on
Whether that part of the ear specialises in high or low frequency hearing
ISCHAEMIC STROKE Symptoms depends on
Which blood vessel is occluded → which area that vessel supplies
The clinical features of an ischemic stroke depend on
Which part of the brain has been damaged (which cerebral artery has been occluded).
Most MS lesions are in which matter?
White Matter
Preterm Perinatal Brain Injury is predominantly damage to
White Matter
WMI
White Matter Injury
What is the external capsule and location?
White matter tract, divides putamen from claustrum
Sclera
White outer layer of eyeball, continious with cornea https://o.quizlet.com/i/Z5kHAib2awlt8xYI14FE6Q_m.jpg
Colour of FF Type/Type II B?
White, ↓myoglobin, ↓blood supply
Recording electrode is attached to a specific neuron and essentially becomes a part of that neuron is called
Whole Cell Recording
What was originally used in studying the plasticity in the hippocampus? What was the problem with this?
Whole animal preparations - very complicated and difficult to study mechanisms
Hippocampal slice preparation is the most
Widely used experimental preparation for studying synapse plasticity
Reelin Deficiency (hippocampus)
Wildtype on left, cortex has layers and hippocampus has distinct Granular Cell layer, tightly packed. Deficiency on right, dispersal of dense hippocampal migratory cell layer (the dense one) https://o.quizlet.com/WeANZXEpEIF-Of5bBNLq4g_m.png
Germline Gene Therapy
Will modify gametic DNA (sperm/egg) to prevent transmission of genetic defect to future generations (i.e. inherited)
How do we accomplish Gene Therapy?
With Viral Vectors
Large Ganglion Cells morphology
With open radiating branching patterns
Association Fibres (1 example)
Within the same hemisphere, Arcuate Fasciculus (bundle of white matter)
Which sex is a better sniffer?
Women
Angular Gyrus function (left) and location?
Writing, Inferior parietal lobule
CT Scanning
Xrays producing virtual slices
Can Astrocytes phagocytose?
Yes
Inhibition Therapy - did it work?
Yes - reached Phase 2 clinical trials and modestly successful Does not stop progression but does help symptoms
Since phosphorylation of AMPA receptors does occur during LTP, maybe this could increase the conductance of existing AMPA receptors?
Yes it does - Increase in conductance is observed - more Na influx, like widening of the channels (like inotropic state of the heart - increased conductance for the same amount of glutamate!) https://o.quizlet.com/NN9z7xi9jo6H3nfQflTKew_m.png
Thalamus and other regions it projects to are mapped?
Yes, somatotopically https://o.quizlet.com/eX5sC8cZO9pLdEtCq64Pcg_m.jpg
Can Astrocytes move?
Yes, they are mobile → actively migrate to site of inflammation, to clean up and protect (chemotaxis, in response to chemokines)
The Neural Tube closes up akin to a
Zip
Find Engram: Step 2 - Label with what specifically?
c-fos, YFP and ChR2
[Figure] Pathways
https://o.quizlet.com/.VDDgZ.j3yu41vxHAqACGA_m.png
[Diagram] Potentiation vs low frequency stimulation
https://o.quizlet.com/2cYa3jeDwZvkPGux8-D7VA_m.png
[Figure] Superior Olivary Complex (my version) (Low frequency sound)
https://o.quizlet.com/C3AMV5UOnlHOPAU4KCvNDg_m.jpg
[Figure] Summary of 1st half of lecture
https://o.quizlet.com/Ebl1Pr9dR8pJlCmPJiPRwA_m.jpg
[Figure] The overall pathway of Reprogramming Cells
https://o.quizlet.com/RM3wkwWS7Hc3zVF8psfj.g_m.png
NMDA receptor-mediated Excitatory Postsynaptic Current (EPSC)
https://o.quizlet.com/bWnkEyA-t6aR311fj26N8Q_m.png
Amyloid Cascade Hypothesis
https://o.quizlet.com/eVIM9hpesA0hMViD9ZSUeg_m.jpg
[Figure] Uncoiled cochlea
https://o.quizlet.com/h6KvSgz3ltNqp-TeN9YVZA_m.jpg
[Diagram] Overview of the taste qualities, the taste receptors that detect them, and examples of natural stimuli
https://o.quizlet.com/siOH-vN03GC2ySRlPEnFlg_m.jpg
miRNA: Normally
miRNA binds mRNA → Inactivates it → Inhibits protein translation
BDNF Functions: Inhibits
miRNA https://o.quizlet.com/A3ZmaAJHIPJ9gNztMYwYcQ_m.jpg
What are SNARE proteins?
v-SNARE proteins on the vesicles containing neurotransmitter interact with t-SNARE proteins on the active zone membrane to dock the vesicles
There is (x) types of rods and (y) types of cones
x = 1 y = 3
Amyloidogenic Pathway Secretases
ß and 𝛾 secretase cleave APP -> release of Aß42
Types of Motor Neurons (2)
α and 𝛾
Non-Amyloidogenic Pathway Secretases
α and 𝛾 secretase cleave APP
Genetic CS4
α-synuclein gene mutation (CS4), pre-synaptic nerves terminals
Neural Pathway of the IHC
• Afferent nerves: IHCs -> (Type I) -> Cochlear Nucleus • Efferent nerves: Lateral Superior Olivary Complex (Brainstem) -> IHCs https://o.quizlet.com/cB3M3ErMHe3Ez.PnDMmzxQ_m.jpg
Neural Pathway of the OHC
• Afferent nerves: OHCs -> (Type II) -> Cochlear Nucleus • Efferent nerves: Medial Superior Olivary Complex (both sides - brainstem) -> OHCs https://o.quizlet.com/CP94GJznlTDOXS6Qc1xAJQ_m.jpg
(2) Preterm Perinatal Brain Injuries (white matter)
• Focal Cystic Necrosis (Cystic Lesions/Holes) • (Non-cystic) Diffuse White Matter Injury https://o.quizlet.com/fZgK9vcKiFl5viRanm3XIQ_m.jpg
The retina projects to which (4) subcortical regions of the brain?
• Lateral Geniculate Nucleus • Superior Colliculus • Suprachiasmatic Nucleus • Pretectum https://o.quizlet.com/TOj-eRudL8bFjl07-wr64w_m.jpg
What are the (3) stimulation and recordings we can do with hippocampal slide preparations?
• Stimulate the Perforant Pathway axons and record the postsynaptic currents from Dentate Gyrus Neurons • Stimulate the Mossy Fibre axons and record the postsynaptic currents from CA3 neurons • Stimulate the Schaffer Collaterals and record the postsynaptic currents from CA1 cells
What happens when you have *onset* of stress / depression?
↑Allopregnanolone, neg. feedback to help you get back to normal
Hypercapnia
↑PCO2 (dissolved in blood) → Reacts with H2O → H2CO3
Relationships between CAG repeat number and disease? (2)
↑Repeats = Earlier acquisition ↑Repeats = More severe form
Sensory Disorders around the world - trend?
↑disorders = developing countries https://o.quizlet.com/1IqIQ0jayuSznqxTQSy53w_m.png
How do you get sustained contraction?
↑frequency of AP = summation of twitches https://o.quizlet.com/qi0TIMsxPU95MGHclaAk6A_m.jpg
Third Pathway: Loss (neurodegeneration) leads to?
↑inhibition of thalamus = Hypokinesia/Rigidity
Adding BDNF to AD induced transgenic mice?
↑performance in water maze ↑synaptophysin expression in hippocampus
If fetus has to face anaerobic conditions and generates reduced levels of ATP, what happens?
↓ATP → Ionic gradient failure → unwanted depolarisation
What happens when you have *chronic* stress / depression?
↓Allopregnanolone
(3) Delivery of oxygen/energy to brain cells (blood perfusion to brain)
↓BP leads to: ↑cell death and ↓ brain blood flow
Post Asphyxial Hypoperfusion is characterised by?
↓CBF due to vasoconstriction + ↓Brain Activity but BP/Oxygenation normal https://o.quizlet.com/3mnckwm9ZDl8eFUzH3x2RA_m.png
Cerebral Blood Flow <20ml/100g/min (2)
↓EEG activity, ↓cerebral metabolic rate of oxygen
Experiment: Fetal responses to maintain brain perfusion during asphyxia - Results?
↓HR (instant) to preserve energy (causes ↓BP) BUT early ↑BP due to peripheral vasoconstriction ↓brain blood flow (ischemia) + ↓blood oxygenation → CNS energy failure → Brain cell death https://o.quizlet.com/BWgqlhx1LP8LQof4EAs7tA_m.png
Hypoxia-ischemia
↓blood flow to brain + ↓oxygen to brain
Cerebral Cooling has shown to decrease (4) in human babies?
↓death ↓mental developmental index ↓disabling cerebral palsy ↓visual impairment
Why do we observe reduced activity?
↓energy supply = brain tries to reduce activity Protective response to prolong time before injury
First Pathway: Loss (neurodegeneration) leads to?
↓inhibition of thalamus = Hyperkinesia
Hypoxemia
↓oxygen in arterial blood
Which gyri are found in the temporal lobe?
Superior, Middle and Inferior
The Medulla Oblongata can be broken down into (2)
*Medullary Pyramids* (pars basilaris medullae) and the Tegmentum
The Pons can be broken down into (3)
*Pars Basilaris* (pontis), Tegmentum and Cerebellar Peduncles
Notochord
A distinct cylinder of mesoderm cells, which condenses at the midline of the mesoderm.
Medullary Pyramids (pars basilaris medullae)
Allow *decussation* of corticospinal (motor) fibres
Cerebellar Peduncles
Allow fibres to and from the cerebellum
What are (3) key structures in the Occipital Lobe?
Association Cortex, Primary and Secondary Visual Cortices
What are the (3) connection fibres?
Association, Commissural and Projection
What structure forms after the initial zygote cleavage?
Blastocyst (has a cavity)
What is Specialisation?
Cells take on particular roles (become more differentiated) - they cannot return to previous totipotent state
The centre of the Neural Tube is called the
Central Canal
The hindbrain is made up of (3)
Cerebellum, pons, and medulla oblongata
The basal ganglia receive their input from the
Cerebral Cortex
Primary Motor Cortex
Has all of the motor neurons, it does a rough job of motor movement so we need help from the planning area and other areas for finer movement and control
Thalamus function?
Complex relay station between (1) brain and target organs and (2) sensory information from periphery to the brain
Pars Basilaris (pontis)
Contains *corticospinal* fibres, from motor cortex to pyramids (where fibers decussate). Contains *brain stem nuclei* which relay information (from the cortex) to *cranial* nerves for the *face*.
The midbrain can be broken down into (4)
Crus Cerebri, Substantia Nigra, Tegmentum, Tectum https://o.quizlet.com/8xjvuK0rpLIXNRDpKWSN3w_m.jpg
Primary Visual Cortex
Detect light/movement in periphery, crude breakdown of what is in your visual field (the raw data) → is sent to the Secondary Visual Cortex
What is lateral to the claustrum?
Extreme Capsule
The Sensory and Motor cortices have a map called the
Homunculus
What are the (3) association cortices?
Frontal, Parietal and Temporal
What are the (4) lobes of the brain?
Frontal, Temporal, Parietal and Occipital
Basal Ganglia are which type of matter?
Grey matter, therefore contain many cell bodies
Inferior Colliculi reflex
In response to auditory stimulus
Superior Colliculi reflex
In response to visual stimulus
The notochord and primitive pit send _____ _____ to the overlying ectoderm that causes a subset of neuroectodermal cells to differentiate into ______ _____ cells.
Inductive Signals, Neural Precursor Cells
Lecture 1
Lecture 1
Lecture 2
Lecture 2
If you are right handed, which hemisphere is dominant?
Left hemisphere
How does a conversation take place for one individual?
Listens → auditory nerve → Primary Auditory Cortex, sound is broken down into tones → Wernicke's Area for interpretation → *Arcuate Fasciculus* → Broca's Area plans verbal response → Primary Motor Cortex at area of throat/tongue/mouth etc.
What happens to an individual when they are *asked* to *write* something?
Listens → auditory nerve → Primary Auditory Cortex, sound is broken down into tones → Wernicke's Area for interpretation → Angular Gyrus → Planning area for hand movements → Exner's Area → Primary Motor Cortex at area of hand
Surgical removal of the temporal lobe to reduce temporal lobe epilepsy also increases the probability of
Loss of memory
Temporal Association Cortex (3)
Memory, agression and intelligence
The tegmentum has which (3) parts? These parts are
Mesencephalic (midbrain), Pontine (pons) and Medullary (Medulla Oblongata). These parts are continuous.
Another name for midbrain?
Mesencephalon
White matter is made of (3)
Myelin, neurites and outgrowths
What part of the blastocyst forms the placenta?
Outer Trophoblast Cells
Another name for pons?
Pontine Nucleus
The Primary Sensory Cortex is located in which gyrus?
Postcentral Gyrus
The Primary Motor Cortex is located in which gyrus?
Precentral Gyrus
Striatum is made up of (2)
Putamen and caudate nucleus
Supramarginal Gyrus (left) function and location?
Reading (orientate head for writing, movement of eyes), Inferior parietal lobule
Primary Auditory Cortex function and location?
Receives information from Auditory Nerve, breaks it down into tones and projects this to the Wernicke's Area for interpretation, Superior Temporal Gyrus
When the sperm meets the egg, what is the name given to these highly developmentally active cells?
Stem Cells or Germ Cells
Which gyri are found in the parietal lobe?
Superior and Inferior
Which gyri are found in the frontal lobe?
Superior, Middle and Inferior
The top and bottom of the Neural Tube differentiate into
Roofplate and Floorplate, respectively. https://o.quizlet.com/92i4P7j6LtV7IgUwkIUvyw_m.png
The Neural Tube becomes the
Rudimentary CNS
The Neural Crests adjacent to the Neural Tube form
Sensory and Autonomic Ganglia
Wernicke's Area function and location?
Sensory aspect of interpreting sounds/speech, Superior Temporal Gyrus
The mesoderm adjacent to the Neural Tube thickens and subdivides to form
Somites https://o.quizlet.com/EDJOx4K3wiuMWEEclGg.Mg_m.png
Parietal Association Cortex function? (3)
Spatial skills, 3D recognition, shapes/faces
Crus Cerebri
The *bridge* between the midbrain and the forebrain which carries *motor* information down
Which Visual Cortex is tricked in optical illusions and why?
The Secondary Visual Cortex, the raw data is analysed incorrectly
The notochord, roof plate and floor plate are transient structures, which means
They disappear once early development is complete
Occipital Cortex function and location?
Vision, Posterior tip of occipital lobe
To see if neural development is fine, at which week stage do women receive a scan?
Week 12 - 14
What are the (5) basal ganglia nuclei?
[(Caudate Nucleus + Putamen) + Globus Pallidus], Subthalamic Nucleus, Substantia Nigra
