Neuroscience P346 Unit 3
What does lesions of the amygdala do?
"flattens" emotions, reduces fear and also affect aggression and memory
What is the Crossed-Extensor Reflex?
Activation of extensor muscles and inhibition of flexors on opposite side
Where is insulin released?
Beta cells of the pancreas
What happens during catabolism?
Between meals the glycogen and triglycerides are broken down (catabolized) for fuel
What are diffuse modulatory systems?
Each system has a small core of neurons (only a few thousand) Most of the cores are found in the central core of the brain and brain stem. Each neuron from the core can influence more than 100,000 postsynaptic neurons spread all over the brain
What was the name of Gage's physician?
John Harlow, who established the connection between Gage's focal brain damage and his behavioral and cognitive changes
What does LH and FSH do in males?
LH stimulates testosterone production from Leydig cells FSH promotes spermatogenesis
What part of the brain supports wanting?
Lateral hypothalamus
What are the two major major pathways of the DESCENDING spinal tracts?
Lateral pathway: axons in the lateral column; voluntary movements of distalmusculature; under direct cortical control Ventromedial pathways: axons in the ventromedial column of the spinal cord;control posture and locomotion; under brain stem control
How does the hypothalamus respond to DECREASED leptin?
NPY/AgRP (Orexigenic peptides) stimulates the lateral hypothalamic area, and inhibits the periventricular nucleus
What kind of aggression does the medial hypothalamus control?
affective projects to the periaqueductal gray matter (PAG) via the dorsal longitudinal fasciculus
What are Extrafusal fibers (work) innervated by?
alpha motorneurons
What is REM sleep atonia?
also known as sleep paralysis (active hallucinating brain)
How do marine animals sleep without drowning?
alternating brain hemispheres as they sleep
What did the reconstruction of Phineas Gage's skull show?
he had sustained extensive damage to his limbic system and parts of frontal cortex
What is Cholecystokinin (CKK)?
hormone present in the lining of the intestines, works synergistically with gastric distension
What is the Kinsey Institute?
hotbed of active research on human sexuality, located at IU
What is the hypophysis?
pituitary gland, greek for "lying under"
What causes Huntington's disease?
polyglutamine (CAG) expansion on exon 1 of chromosome 4 - ≥ 36 CAG repeats will result in disease onset - likely causes dysfunctional corticostriatal activity Symptoms usually manifest around mid-life (35-45 years of age)
What kind of aggression does the lateral hypothalamus control?
predatory projects to the ventral tegmental area (VTA) via the medial forebrain bundle
What is the Sexually dimorphic nucleus (SDN)?
preoptic area of the anterior hypothalamus clustered near the 3rd ventricle, very distinct in animals like rats involved with reproductive behaviors
What is the Interstitial nuclei (INAH)?
preoptic-anterior hypothalamic area that influences gonadotropin typically larger in males, but not always the case
What is Intracranial Self-Stimulation (ICSS)?
procedure where animals learn to push a lever for stimulation stimulates Ventral Tegmental Area (VTA), which releases Dopamine to the Nucleus Accumbens (NAc), known as the Mesolimbic Pathway
What is epilepsy characterized by?
recurrent seizures
What NT causes stress eating?
reduced serotonin levels, also commonly caused by depression
What does Hypocretin (orexin) do?
regulates arousal, wakefulness, and appetite Excites NE, DA, 5-HT, Cholinergic, &histaminergic
What does insulin do?
regulates blood glucose levels Highest during Substrate phase
What does Gonadotropin-releasing hormone (GnRH) do?
releases luteinizing hormone (LH) and Follicle-stimulating hormone (FSH) from the anterior pituitary which act directly on the gonads
Why do we think we sleep?
restoration & preservation
What is an example of an androgen?
testosterone
What areas of the brain are associated with the activation of appropriate motor neuron pools?
the brain stem and spinal cord
What do most motor actions require?
the integration of sensory and motor functions
What is liking vs wanting?
the pleasure of sensory experience (hedonic) vs motivation to seek out the experience
What is the "default mode" network?
when the brain is at rest/self reflection
How can we guess which hemisphere regulates language in someone?
which ever hemisphere is opposite of their dominant hand
What are the EEG frequency ranges?
γ Gamma: 30-90 Hz ("cognitive" frequency band; active and attentive cortex) β Beta: 15-30 Hz (activated cortex) α Alpha: 8-13 Hz (quiet waking state) θ Theta: 4-7 Hz (sleep stages and waking stages - in between stage) δ Delta: less than 4 Hz (sleep stages, especially "deep sleep")
What is the phenotype of Parkinson's?
• Bradykinesia- Slowness in initiation and execution of voluntary movements • Rigidity - Increase muscle tone and increase resistance to movement (arms and legs stiff) • Tremor - Usually tremor at rest (arms and legs shake) • Postural Instability - abnormal fixation of posture (stoop when standing) • Gait Disturbance - Shuffling Feet • Hypokinetic (reduced) movement
What is the internal mentation hypothesis?
- supports thinking & remembering - daydreaming - just processing past & future events
What are the three nuclei of the amygdala?
1. Corticomedial nuclei 2. Basolateral nuclei 3. Central nucleus
What are symptoms of Klüver-Bucy syndrome?
1. Good vision, but poor visual recognition (psychic blindness) 2. Oral fixation / oral tendencies 3. Inappropriate sexual behavior 4. Decreased fear and aggression
How much of your life is spent sleeping?
1/3
What are the stages of language acquisition?
6 months: Babbling 18 months: 150 words; speaks ~50 3 year old: 100s words; full sentences Adult: Tens of thousands of word
What is sexual dimorphism?
A sex-related difference in structure or behavior
What are the two long-term ways of regulating eating behavior?
ANABOLISM during the prandial state CATABOLISM during the postabsorptive state
What happens during anabolism?
After a meal, excess energy is stored as glycogen and triglycerides
How does the amygdala learn?
Amygdala neurons can learn to respond to neutral stimuli that predict painful stimuli and then evoke a fearful response
What is the Posner task?
An arrow will precede each stimulus, your job is to tell when that stimuli appears, however the arrow sometimes points the wrong way Invalid cue: hurts performance, slowest reaction Neutral: no arrow, serves as baseline Valid cue: helps performance, fastest reaction
What allows testosterone to become estradiol?
Aromatase (estradiol cannot pass the BBB)
What does the Serotonergic (5-HT) system regulate?
Arousal / waking / pain located in the Raphe Nuclei
What does the Noradrenergic (NE) system regulate?
Attention / arousal / waking / learning / anxiety / pain / mood / metabolism located in the Locus coeruleus
What does the Cholinergic (ACh) system regulate?
Attention / learning / sensory processing located in Basal forebrain & Brain stem
What does LH and FSH do in females?
BOTH LH and FSH stimulate excretion of estrogen from the ovaries FSH stimulates follicular development and ovulation
What are the contemporary theories of emotion?
Basic Emotions (hard wired areas) & Dimensional Emotion (lvls of arousal and strength)
What is the lipostatic hypothesis?
Body regulates the amount of energy stored in fat cells. Too little fat? Release ghrelin to increase hunger. Too much fat? Release leptin to increase satiety.
What are the two forms of attention?
Bottom-up/Exogenous: world grabs our attention Top-down/Endogenous: direct our attention to the world
What is the Tectospinal tract responsible for?
Brings information from the visual system (retina) Map of the world Useful for orientation responses
What are the two language areas of the brain and where are they located?
Broca's area (1861) found in the left frontal lobe Wernicke's area (1874) found in the superior surface of dominant temporal lobe
What are the three phases of short-term regulation of feeding behavior?
Cephalic phase Gastric Phase Substrate (Intestinal) Phase
Which diffuse neuromodulatory system is involved in falling asleep and the non-REM state?
Cholinergic system (Midbrain, Pons, PMT)
What are the two kinds of tracts found in the LATERAL pathways?
Corticospinal tract Rubrospinal tract (Control of distal muscles: mainly flexors of the hands and feet)
How does dopamine (DA) modulate the BG INDIRECT pathway?
DA INHIBITS striatopallidal neurons via D2 receptor activation (K+ exiting the cell), which decreases the activity of striatopallidal neurons (GABA) inhibiting the GPe hence, more glut is released fromthalamus to the cortex
How does dopamine (DA) modulate the BG DIRECT pathway?
DA from the SNc ACTIVATES/FACILITATES striatonigral neurons via D1 receptor activation (Na+ entry into the cell) hence, more glut is released from the thalamus to the cortex
What does the 'basic' BG DIRECT/striatonigral pathway do?
DECREASES inhibition of SNr/GPi (GABA) to the thalamus, further further activating cortex creating a 'positive feedback loop' Cortex (↑ glut+) --> Striatum (↑ GABA-) --> SNr/GPi (↓ GABA-) --> Thalamus (↑ glut+) --> Cortex
What causes masculinization in the brain?
Estradiol, which activates receptors mainly found in the hypothalamus and pituitary
What bodily functions does the parasympathetic nervous system regulate?
Everything outside the SNS, "rest & digest" Ex: digestions, growth, immune response, energy storage
What is the flexor withdrawal reflex an example of?
Excitatory Spinal Input
What allows us to consciously process FACES?
FFA (fusiform face area)
What are examples of neural bases for emotions?
Fear and anxiety Anger and aggression Reinforcement and Reward
What are the two patterns of communication?
Focused and Broad (diffused)
What are the two kinds of seizures?
Generalized and Partial
What are the three basal ganglion neurotransmitters?
Glutamate - excitatory (+) GABA - inhibitory (-) Dopamine - modulatory
What are the three homeostasis responses controlled by the hypothalamus?
Humoral response Visceromotor response Somatic motor response
What is Huntington's disease phenotype?
Hyperkinetic movement (Chorea) Abnormal gait Bradykinesia Rigidity Cognitive deficits (Executive function & Procedural memory)
What does the BG hyperdirect pathway do?
INCREASES activation of the STN (glut+), decreasing cortical activation Cortex (↑ glut+) --> STN (↑ glut+) --> SNr/GPi (↑ GABA-) --> Thalamus (↓glut+) --> Cortex
What does the 'basic' BG INDIRECT/striatopallidal pathway do?
INCREASES inhibition of SNr/GPi (GABA-) to the thalamus, decreasing cortical activation creating a 'negative feedback loop' Cortex (↑ glut+) --> Striatum (↑ GABA-) --> GPe (↓ GABA-) --> STN (↑ glut+) --> SNr/GPi (↑ GABA-) --> Thalamus (↓glut+) --> Cortex
How does lesions of the VENTROMEDIAL hypothalamus affect body weight?
it causes obesity
What is the Wada procedure?
Inject anesthetic or barbiturate into left carotid artery. Then, chat with patient and listen for a reduction in language abilities a reduction indicates a left hemisphere language dominance
What is Anorexia Nervosa?
Intense fear if gaining weight
How does lesions of the LATERAL hypothalamus affect body weight?
it causes starvation
What parts of the brain are primarily involved with emotion?
Limbic structures, including cortex
How does Huntington's disease affect the BG pathway?
Loss of negative feedback to striatonigral neurons decreases inhibition ("disinhibition") of SNr/GPi (GABA) to the thalamus hence, excessive glut is released from thethalamus to the cortex
How does the kidney communicate with the brain?
Low blood volume and pressure → kidneys secrete renin → production of angiotensin II→ 1) affects blood vessels to increase blood pressure; 2) activates subfornical organ → - activates cells in lateral hypothalamus - activates ADH production, thirst
Which kinds of brain waves are strongly synchronized?
Lower frequencies; high amplitude
How does the hypothalamus respond to ELEVATED leptin?
MSH/CART (Anorectic peptides) inhibits the lateral hypothalamic area, and stimulates the periventricular nucleus (stimulates ACTH release of the anterior pituitary) inhibits feeding behavior
Where are oxytocin and vasopressin/ADH released?
Magnocellular neurosecretory cells in the Posterior Pituitary Lobe
What does vasopressin/ADH do?
Mediates stress response and stimulates thirst when blood salt & pressure levels are off stands for antidiuretic hormone
What does the Dopaminergic (DA) system regulate?
Movement initiation / reward processing located in Substantia Nigra & Ventral Tegmental area
What happens to the length of REM as you sleep?
it gets increasingly longer
Is dyslexia genetic?
No, but it has a strong genetic link. commonly found with high amounts of KIAA0319, a neuronal migration gene
What are the four modulatory systems found in the CNS?
Noradrenergic (NE) system (Locus coeruleus) Serotonergic (5-HT) system (Raphe Nuclei) Dopaminergic (DA) system (Substantia Nigra & Ventral Tegmental area) Cholinergic (ACh) system (Basal forebrain & Brain stem)
What two diffuse neuromodulatory systems are involved in wakefulness and awakening?
Norepinephrinergic system (locus coeruleus) and Serotoninergic system (raphe nucleus)
What allows us to consciously process PLACES?
PPA (parahippocampal place area)
What does dyslexia impair?
language processing
Where are Corticotropin and gonadotropin-releasing hormone released?
Parvocellular neurosecretory cells involved in Ovulation, Sperm prod., cortisol secretion, growth, protein synthesis, milk secretion
What brain areas are involved in the default mode network?
Posterior cingulate cortex (Feeling of being an "agent") Medial prefrontal cortex (Top down control) Medial temporal lobes (Memory)
What kind of neurosecretory cells does each pituitary lobe contain?
Posterior contains Magnocellular Anterior contains Parvocellular
How does focused and broad communication differ?
Precise point-to-point connectivity VS Effects many downstream targets
What neurotransmitters act in the PNS?
Preganglionic: ACh Postganglionic: ACh
What neurotransmitters act in the SNS?
Preganglionic: ACh Postganglionic: Noradrenaline
What are the frontal eye fields (FEF), what do they do?
Premotor area that can direct looking behavior, input from many visual areas Stimulation improves stimulus detection
What are the two brain circuits of visual attention?
Pulvinar nucleus (visual relay) Frontal eye fields (FEF) (orientation)
What is the neuropathology of Huntington's?
Reduced brain weight Enlarge ventricles Striatal and cortical atrophy - Loss of Medium Spiny Neurons(MSNs) - Loss of cortical projection neurons(CPNs) Impaired corticostriatal connectivity and information processing
How is the adrenal gland regulated?
Release of corticotropin-releasing hormone (CRH) by periventricular hypothalamic neurons (anterior pituitary) in response to stress. CRH stimulates the release of adrenocorticotropic hormone (ACTH) into the bloodstream. ACTH triggers release of cortisol (steroid hormone) from adrenal glands (adrenal cortex). Cortisol binds to neurons throughout the CNS
What is the sensorimotor system?
Sensory information used by all levels of the motor system
What are the two theories of the default mode network?
Sentinel hypothesis Internal mentation hypothesis
What composes the somatic nervous system?
Skeletal muscles & skin sensations
What happens to speech in Broca's aphasia?
Speech is nonfluent, agrammatical Okay with nouns (oar, bee) but not function words (or, be)
What does oxytocin do?
Starts uterine contractions and simulates milk release & production known as the "love" neurohormone
What is gastric distension?
Stretching of the stomach --> mechanosensory axons --> inhibits feeding behavior
What is the benefit of having brain rhythms?
Synchronize populations of neurons representing the same stimulus, temporarily organizing neural activity
What does the pulvinar nucleus do?
Thalamic relay: connects visual areas in the occipital, parietal (where path), and temporal (what path) lobes in other words, directs attention shifts
What is the somatic motor response?
lateral hypothalamus incites a somatic motor behavioral response
What is paradoxical sleep?
The body's condition during REM sleep when the muscles are relaxed but other systems are active
What is affective neuroscience?
The study of the neuronal basis of mood and emotion, as well as affective disorders (Ex: depression, bipolar)
How do alpha and gamma motor neurons work together?
They have have opposite effects on Ia output • Alpha motor neurons --> decreases Ia activity • Gamma motor neurons --> increases Ia activity
How do we perceive things we put our attention in?
We respond faster & more accurately to parts of the world we focus on
What is the Mesolimbic Pathway?
VTA --> ventral striatum (NAc) - Major integrative center for converting motivation to action - Mediates rewarding effects of drug abuse,eating, sex, etc
What part of the brain supports liking?
Ventral palladium (VP)
What are the four kinds of tracts found in the VENTROMEDIAL pathways?
Vestibulospinal tract Tectospinal tract Pontine reticulospinal tract Medullary reticulospinal tract (Control proximal and axial muscles, posture and locomotion, under brain stem control)
What are the two major functional brain states in s
Waking & Sleep
How have we found implications of unconscious emotion?
While showing a subject either a neutral or angry face, an image of a neutral face would very briefly be preceded by an angry one. Though they had not consciously recognized recognized it, there was still activation found in the amygdala.
What is a Satiety signal?
a factor that reduces the drive to eat Ex: leptin
What are some ideas of why our brain has rhythms?
a.) to "disconnect" the brain from acute inputs during sleep b.) to coordinate neurons in different parts of the brain c.) no function, just by-products of an inherent tendency
How many lobotomies were conducted in the US?
about 50,000 (mostly in the 40s & 50s) allowed Egaz Moniz to win Nobel in 1949
What is parabiosis?
anatomical joining of two individuals
What are the six "basic" emotions?
anger, disgust, fear, happiness, sadness, surprise
What kind of drug can treat bulimia nervosa?
anti-depressants
What happens in the substrate (intestinal) phase?
as the stomach fills, the partially digested food move into the intestine and nutrients begin to be absorbed into the bloodstream
What areas of the brain are associated with motor planning?
association areas of the neocortex and basal ganglia
What is the sentinel hypothesis?
at rest we using peripheral vision to monitor environment for danger - simultagnosia
What is predatory and affective aggression?
attacking for food vs attacking to "impress"
What is the neurophysiology of attention?
attention increases metabolism of the relevant brain areas
What is modulation or "scaling" of the basal ganglia?
balancing of motor movements
What is the difference between prairie and montane voles?
basically nothing, other than that prairie voles are social and monogamous, while montane voles are not
Which amygdala nucleus creates the emotional experience?
basolateral nuclei
What do the lateral and medial zones of the hypothalamus regulate?
behaviors such as feeding, etc.
Which amygdala nucleus creates the behavioral reaction/autonomic response?
central nucleus
What does the periventricular zone of the hypothalamus regulate?
communicates with the pituitary and regulates hormonal signaling
What two ways can motivation take form?
concrete (physical) and abstract (goals)
What is the PING model?
constantly active excitatory input excites an excitatory (E) cell, which then activates an inhibitory (I) cell this is the basis for neuronal wavelengths
What does the posterior pituitary lobe do?
contains magnocellular neurosecretory cells communicates the kidney and brain
What does the anterior pituitary lobe do?
contains parvocellular neurosecretory cells regulates the adrenal gland
What is reciprocal inhibition?
contraction of one set of muscle is accompanied by the relaxation of the antagonist muscle Ex. Stretch reflex
What does the Electroencephalogram (EEG) measure?
current flow due to synaptic activity on dendrites of pyramidal neurons
What are convulsants?
drugs that cause seizures
What are the specific traits of living things?
eating, breathing, growing, and reproducing
How does serotonin affect aggression?
elevated serotonin decreases aggression
How does serotonin affect hunger?
elevates serotonin suppresses appetite
What is the James-Lange theory?
emotion is experienced in response to physiological changes in body
What is the Canon-Bard Theory?
emotions occur independent of emotional expression—no correlation with physiological state
What are examples of an estrogen?
estradiol & progesterone
What are cognitive examples of sexual dimorphism?
females typically have better verbal reasoning males typically have better map and mathematical reasoning
What are the four "F's" of the sympathetic nervous system?
flight, fright, fight, and sex
What causes Klüver-Bucy syndrome?
follows temporal lobe/amygdala damage Ex: after bilateral removal of the temporal lobes in rhesus monkeys
How is serotonin made?
from the amino acid tryptophan present in food, mainly carbs
What are Intrafusal fibers (muscle spindles) innervated by?
gamma motorneurons
What is Huntington's disease?
genetic autosomal dominant neurodegenerative disease characterized by cognitive, psychiatric, and motor deficits
What hormone stimulates hunger?
ghrelin
What are distal muscles responsible for?
hands, feet, digits (fingers and toes) movement
What is known as the body brain bridge?
hypothalamus
How is vasopressin related to marriage?
in men, low vasopressin gene --> less satisfaction in marriage
What is anomia?
inability to find the right word, symptom of Broca's aphasia
What are the three zones of the hypothalamus?
lateral, medial, and periventricular
Which hemisphere is dominant for language?
left hemisphere
What do EEG rhythms correlate with?
level of attentiveness, sleeping, waking, seizures, coma
What is Parkinson's caused by?
loss of Dopaminergic neurons in the Substantia Nigra (SNc) D1 (↓ GABA-) in direct D2 (↑ GABA-) in indirect
What is anorexia?
loss of appetite
What areas of the brain are associated with motor sequencing?
motor cortex and cerebellum
What does the golgi tendon organ sense?
muscle tension, or force of contraction
What is the visceromotor response?
neurons in the hypothalamus adjust the sympathetic and parasympathetic nervous system
What is the humoral response?
neurons in the hypothalamus release of hormones into the bloodstream
What is polyandry?
one female, multiple males
What is aphasia?
partial or complete loss of language abilities following brain damage, often WITHOUT loss of cognitive or motor function
What are seizures?
pathological states of synchronized brain activity, often indicative of brain injury or pathology
How does ghrelin work?
peptide secreted from the stomach that stimulates appetite by activating orexigenic (NPY/AgRP-containing) neurons found in the arcuate nucleus in the hypothalamus
What part of the hypothalamus controls the autonomic nervous system (ANS)?
periventricular area
What happens in the gastric phase?
physiological responses increase when you start chewing, swallowing, and filling your stomach
What did we learn from S.M.?
selective damage to the amygdala caused a deficit in recognizing fear in faces, but not happiness
What do the gonads release?
sex hormones (testosterone and estrodiol)
What are proximal muscles responsible for?
shoulder, elbow, pelvis, knee movement
What happens during the cephalic phase?
sight and smell --> physiological processes - Secretion of saliva, digestive juices into your stomach - PNS is involved
What differentiates a coma and sleep?
sleep is readily reversible
What is Bradykinesia?
slowness of INITIATING movement
Why type of cells does the ANS act upon?
smooth muscle, cardiac muscle, and gland cells
What does the hypothalamus integrate?
somatic and visceral responses in accordance with the needs of the brain (homeostasis)
What is a materialist?
someone who believes consciousness arises from physical processes, and CAN be understood by studying structure and function of the nervous system
What is a dualist?
someone who believes mind and body are different things; consciousness CANNOT be fully explained by physical processes
Which sleep stage contains sleep spindles and K complexes?
stage 2 NREM
What did W.R. Hess win the Nobel prize for?
stimulating different areas of the hypothalamus in cats to test different types of aggression
What is the SNc?
substantia nigra pars compacta (source of the modulatory dopamine pathway)
What is the SNr?
substantia nigra pars reticulata
What are the two divisions of the autonomic nervous system?
sympathetic and parasympathetic
What is the Vestibulospinal tract responsible for?
to keep the head balanced on the shoulders as the body moves, brings information from the vestibular apparatus responsible for balance
What MIGHT narcolepsy be caused by?
too few hypocretin neurons
What are axial muscles responsible for?
trunk movement
What kind of waves does dreaming occur in?
typically theta (higher frequency; lower amplitude)
What is the gene FOXP2 involved with?
verbal dyspraxia; specific language impairment (SLI)
What are the two basic ways of generating synchronicity in the brain?
via pacemaker or mutual coordination
