MASTER Brain Facts/Neuroscience: Science of the Brain Glossary
endorphins
"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure. released by brain neurons in times of stress to minimize pain and enhance adaptive behavior.
semantic dementia
(a type of Alzheimer's Disease), can cause fascinating patterns of breakdown of semantic memory. Early on, patients will be quite capable of telling you that the pictures they are being shown in an experiment are of a cat, or a dog, or of a car, or a train. Later on in the disease, they may hesitate to call a picture of a mouse a mouse, saying instead that it is a dog. What this confirms is that factual information is organised categorically, with animate information stored together in one place well away from inanimate information.
intellectual disability
(formerly referred to as mental retardation) a condition of limited mental ability, indicated by an intelligence score of 70 or below and difficulty in adapting to the demands of life; varies from mild to profound.
oxyhaemoglobin
(hence the signal in fMRI is called the Blood-OxygenationLevel-Dependent signal - BOLD). The molecule formed when haemoglobin binds to oxygen molecules. The difference in magnetic properties of this compound and its deoxygenated state is used in fMRI. An increase in neuronal activity leads to a greater energy consumption, which leads to less of this compound. However, cerebral blood flow then increases the concentration of this compound.
neurotoxins
(nerve agents) that disrupt this critical process, such as enzyme inhibitors that are but a step from the agents of biological warfare.
6
*A monkey raised from birth to how many months lost vision in one eye when it was closed?
100 billion
*About how many neurons are in the brain?
1/2
*About what fraction of neurons generated during development function in the adult?
8
*Beyond what age does the blindness in one eye become permanent?
100x
*By what factor can myelination increase the firing of a neuron?
mRNA
*During protein production, this gene uses a molecule to send a message with instructions for the amino acids needed to manufacture a protein.
50-100
*Every person has between how many sensory cells on each taste bud?
5,000-10,000
*Every person has between how many taste buds?
90%
*Glia account for what percent of neuronal migration?
radially from the intermediate zone to the cortex?
*How do glia move during neuronal migration?
speeds up to several hundred miles per hour.
*How fast can action potentials travel?
From a tiny fraction of an inch (or centimeter) to three feet (about one meter) or more
*How long can axons extend?
15 min
*How long does an MRI procedure last?
10-15 min
*How long does the first REM period last?
17 in (43 cm)
*How long is the spinal cord?
25,000
*How many genes does each cell contain?
30,000
*How many nerves are in the auditory nerve?
20,000-25,000
*How many pairs of genes are contained in the 23 chromosomes?
125 million
*How many photoreceptors are in each eye?
3 lbs
*How much does the brain weigh?
Every 90 min.
*How often does REM sleep occur?
Less than 1/10 in
*How thick is the primary visual cortex?
nervous system
*More than 1,000 disorders of what parts of the body result in more hospitalizations than any other disease group, including heart disease and cancer?
two-thirds
*More than how much of the cerebral cortex is folded into grooves?
9
*Researchers have identified at least how many ephrins?
15
*Researchers have identified at least how many semaphorins?
95
*Rods constitute what percent of photoreceptors in the eye?
triple and quadruple screen blood tests
*Tests that can accurately detect Down Syndrome in 70% of fetuses
10 times
*The brain contains at least how many more glia than neurons?
3
*The intricate communication systems in the brain and the nervous system begin to develop about how many weeks after gestation?
early 20s
*The last step in the creation of an adult human brain, the frontal lobes, whose function includes judgment, insight, and impulse control, continues into the what age?
cortisol
*The levels of which glucocorticoid peak in the early hours?
4
*Until a few decades ago, ophthalmologists waited until children reached the age of what before operating to align the eyes, prescribing exercises, or using an eye patch for patients with strabismus?
red, green, blue
*What are the three types of cones?
red, green
*What cones are found in the fovea?
specialized class of glia
*What do cells closest to the release of sonic hedgehog turn into?
interneurons
*What do cells farthest from the release of sonic hedgehog turn into?
motor neurons
*What do cells slightly further from the release of sonic hedgehog turn into?
3/4
*What fraction of focusing does the cornea do to the light once it passes through the eye?
Loss of function or death of photoreceptors
*What is the major cause of blindness?
Glia
*What is the most common guidance mechanism in migration?
30
*What percent of the brain is devoted to vision?
At birth or early childhood
*When can vision be restored in patients with strabismus?
3-4 weeks after a human baby is conceived.
*When does migration begin?
7
*Which week do the first signs of the eyes and the brain's hemispheres appear?
deepest
*the cells that arrive the earliest (the oldest ones) form what layer of the cortex?
outermost layer
*the late-arriving (the youngest) neurons form what layer of the cortex?
spinocerebellar ataxia
- Rare, degenerative, genetic disorder. Is an impairment of specific nerve fibers carrying messages to and from the brain resulting in degeneration of the HINDBRAIN (cerebellum, the pons and the medulla
tumour necrosis factors
- this release allows bacteria to cross the blood brain barrier
visual motion
-Object moves across the retina, signifying movement by changing projected location on retina
mineralocorticoids
1 of 3 the major groups of steroid hormones produced by the adrenal cortex; stim: by ACTH and low blood volume; func: reabsorb NA+ & water, including aldosterone.
G protein
A GTP-binding protein that relays signals from a plasma membrane signal receptor, known as a G-protein linked receptor, to other signal-transduction proteins inside the cell. When such a receptor is activated, it in turn activates this protein, causing it to bind a molecule of GTP in place of GDP. Hydrolysis of the bound GTP to GDP inactivates this protein.
Arvid Carlsson
A Nobel Laureate who discovered it was dopamine that is missing in Parkinson's in the substantia nigra; used rabbits and mice.
exposure and response prevention
A behavioral treatment for obsessive-compulsive disorder that exposes a client to anxiety-arousing thoughts or situations and then prevents the client from performing his or her compulsive acts.
somatosensory cortex
A brain area at the front of the parietal lobes that registers and processes body sensations
anterior cingulate gyrus
A brain area that reacts as if there is a real stressor at hand; involved in major depression. This region normally integrates aspects of cognition and emotion, is the chief experimental target for deep brain stimulation in severely depressed patients who have not responded to other treatments.
anterior temporal lobe
A brain region involved in sentence level comprehension.
episodic memory
A category of long-term memory that involves the recollection of specific events, situations and experiences.
stimulus
A change in an organism's surroundings that causes the organism to react
excitation
A change in the electrical state of a neuron that is associated with an enhanced probability of action potentials.
histamine
A chemical released by the body during an inflammatory response, especially by an insect or pollen, that causes the blood vessels to dilate.
chemokines
A chemical secreted by blood vessel endothelium and monocytes during an immune response to attract phagocytes to an area
stretch reflex
A class of reflexes initiated by stretching of muscle spindles and causes a contraction of the stimulated muscle and inhibits its antagonist.
psychotic symptoms
A class of symptoms that include delusions, hallucinations, ideas of reference, and disorders of thought.
tissue plasminogen activator (tPA)
A clot-dissolving bioengineered drug, it is now a standard treatment in many hospitals. This medication opens blocked vessels rapidly to restore circulation before oxygen loss causes permanent damage. Given within three hours of a stroke, it often can help in limiting the ensuing brain damage.
gamma hydroxy-butyrate (GHB)
A club drug predominantly a central nervous system depressant and is often colourless, tasteless and odourless, making it easy to add to beverages. It has been abused for its euphoric, sedative, and anabolic (body-building) effects and has been associated with sexual assault.
ketamine
A club drug that has sedative, hypnotic, analgesic, and hallucinogenic properties. It is marketed in the United States and a number of foreign countries as a general anesthetic — a drug that brings about a reversible loss of consciousness — in both human and veterinary medical practice. It blocks NMDA glutamate receptors and has been shown to alleviated symptoms related to depression. Because it has many side effects, it is not likely to be used clinically, but these findings have set off an exciting search for new pharmacologic approaches.
cochlea
A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses. It is tuned along its length to different frequencies.
brain
A complex chemical and electrical organism. It weighs 3 pounds. No two are alike.
Duchenne muscular dystrophy
A condition with symmetrical weakness and wasting of pelvic, shoulder, and proximal limb muscles
cirrhosis
A disease of the liver in which useless scar tissue replaces normal liver tissue due to high levels of chronic alcohol consumption.
Walker-Warburg syndrome
A disease that causes severe problems involving the brain, eyes, and muscles, leading to death in infancy or early childhood. At least five genes are known to be associated with this disease, with still others yet to be discovered.
epilepsy
A disorder of the CNS characterized by loss of consciousness and chronic brain disorder characterized by recurrent seizure activity. Can be idiopathic or symptomatic and generalized or partial. Attacks may be provoked by tiredness, missed meals, low blood sugar, alcohol, or flickering television screens.
limbic system
A doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres; associated with emotions such as fear and aggression and drives such as those for food and sex. Includes the hippocampus, amygdala, and hypothalamus. Neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.
AP5
A drug that blocks the glutamate binding site on NMDA receptors.
rohypnol
A fairly tasteless and odorless drug that causes sleepiness, sedation, and the inability to remember events that occurred when one was under the influence of the drug.
mono-sodium glutamate
A flavor enhancer. MSG /Seaweed salt
cortisol
A glucocorticoid secreted by the adrenal glands, which sit on top of the kidneys; it is secreted in response to stress and helps trigger the changes of the fight or flight response, including increased blood glucose, altered immune function, and reduction in nonessential body functions. a steroid hormone that is the key to understanding the next phase of the stress response. It raises blood sugar and other metabolic fuels such as fatty acids. This often occurs at the expense of proteins that are broken down into fuels required immediately - instant 'chocolate bars' for the muscles and brain. It also helps adrenaline to raise blood pressure and, in the short term, makes you feel good. It also turns off growth, digestion, inflammation, and even woundhealing - clearly things that can be better done later on. It also turns off sex.
estrogens
A group of sex hormones found more abundantly in females than males. They are responsible for female sexual maturation and other functions.
leptin
A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite.
progesterone
A hormone produced by the ovaries which acts with estrogen to bring about the menstrual cycle. This hormone can be used to prevent death in patients with a traumatic head injury.
cytoplasm
A jellylike fluid inside the cell in which the organelles are suspended
amygdala
A limbic system structure involved in memory and emotion, particularly fear and aggression.
cholesterol
A lipid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids.
cerebral palsy
A loss or deficiency of motor control with involuntary spasms caused by permanent brain damage present at birth
glutamate
A major excitatory neurotransmitter; involved in memory. Too much leads to cell death. A common amino acid used throughout our bodies to build proteins. It is the neurotransmitter that functions at the most plastic synapses of our brains - those that exhibit LTP and LTD.
tectorial membrane
A membrane located above the basilar membrane; serves as a shelf against which the cilia of the auditory hair cells move.
major depression
A mental disorder characterized by sadness, hopelessness, pessimism, loss of interest in life, and reduced emotional well-being. The disorder also comes with disturbances of sleep and appetite, decreased energy, and often cognitive disturbances such as difficulty concentrating and remembering. It is as disabling as heart disease or arthritis. What's more, individuals are at a significantly elevated risk of suicide. While both genes and the environment play a role in an individual's risk for this disorder, stress also can trigger an episode. We now know that the physical symptoms may reflect disturbances in the hypothalamus, resulting in an excessive production of stress hormones. Cortisol is over-produced and recent work suggests that the hippocampus also shrinks in this condition. Such findings have led psychiatrists to think of it as severe long-term stress. It is not at all certain that the increased cortisol is the primary cause of this illness rather than it being simply a consequence of severe psychological upset and its attendant stress. However, patients can be markedly helped by blocking the production or action of cortisol, particularly those in whom classical antidepressant drug treatments do not work. Anti-depressant drugs often help to normalise the overactive HPA axis. One idea is that they do so, in part, by adjusting the density of MR and GR receptors in the brain, particularly in the hippocampus.
Pavlovian learning
A method to cause a reflex response or behavior by training with repetitive action. The cerebellum of the brain is essential to this.
ligand
A molecule that binds specifically to a receptor site of another molecule.
action potential
A momentary reversal in electrical potential across a plasma membrane (as of a nerve cell or muscle fiber) that occurs when a cell has been activated by a stimulus. Internal negative to positive charge.
hippocampus
A neural center located in the limbic system that helps process explicit memories for storage. It is C-shaped. One of the most active regions for neurogenesis in the brain. Encodes events and places.
hypothalamus
A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward. It is the control center for appetites, defensive and reproductive behaviors, and sleep-wakefulness. Sex differences are found in the size and shape of brain structures in this structure. The key brain area regulating many of our hormones. It has strong inputs from areas of the brain processing emotional information, including the amygdala, and from regions of the brainstem controlling sympathetic nervous responses. It integrates these to produce a co-ordinated hormonal output that stimulates the next part of the circuit - the pituitary gland.
adenosine
A neurochemical that inhibits wakefulness, serving the purpose of slowing down cellular activity and diminishing arousal. Levels of this decrease during sleep.
dopamine
A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.
norepinephrine
A neurotransmitter involved in arousal, as well as in learning and mood regulation. Scientists found that when certain immature neurons are maintained in a dish with no other cell types, they produce this neurotransmitter. Deficiencies in this neurotransmitter occur in patients with Alzheimer's disease, Parkinson's disease, and Korsakoff's syndrome.
serotonin
A neurotransmitter that affects hunger, sleep, arousal, and mood. This neurotransmitter is present in the brain and other tissues, particularly blood platelets and the lining of the digestive tract
acetylcholine (ACh)
A neurotransmitter that enables learning and memory and also triggers muscle contraction. Synthesized in axon terminals. Produces a calming effect as part of the parasympathetic system.
electrical stimulation therapy
A new form of epilepsy treatment, it was introduced as another option for hard-to-control partial seizures. An implanted device delivers small bursts of electrical energy to the brain via the vagus nerve on the side of the neck. While not curative, vagal nerve stimulation has been shown to reduce the frequency of partial seizures in many patients.
subthalamic nucleus
A nucleus that lies just below the thalamus and is connected to the basal ganglia; deep brain stimulation applied to this site has been used to treat Parkinson's disease
nucleus
A part of the cell containing DNA and RNA and responsible for growth and reproduction.
reward pathway
A particular pathway within the limbic system that is associated with both feelings of reward in day-to-day life and the feelings of pleasure that lead to cravings and addiction.
lateral geniculate nucleus
A place from the thalamus that receives messages from the optic nerve. These messages are sent to the visual cortices located in the occipital lobe of the brain
cortical plasticity
A principle that states that the brain allows the non-dominant hemisphere to take over a function that was formerly controlled by the impaired dominant hemisphere. The map of the body in the somatosensory area can vary with experience.
amyloid precursor protein (APP)
A protein from which beta amyloid is formed; found on chromosome 21.
insulin
A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues
sonic hedgehog
A protein secreted by the mesoderm that signals ectoderm cells to become nervous tissue in the spinal cord. Is secreted and diffuses away from the floor plate.
huntingtin
A protein whose normal function is still unknown, it is widely distributed in the brain and appears to be associated with proteins involved in transcription, protein turnover, and energy production. Scientists suspect that Huntington's disease is caused by the gain of a new and toxic function among these proteins.
electrical depolarisation
A reduction in the difference of electrical potential that exists across the membrane of a nerve
iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening.
vertebral column
A series of irregularly shaped bones called vertebrae that house the spinal cord.
inhibitory interneuron
A short neuron which forms an inhibitory synapse with a motor neuron. Inhibits the opposing response of a muscle.
narcolepsy
A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times. This problem is due to the loss of nerve cells in the lateral hypothalamus that contain the neurotransmitter orexin.
transistor
A small electronic device used in a circuit as an amplifier or switch.
malleus
A small hammer-shaped ossicle in the middle ear that transmits vibrations of the eardrum to the incus.
basilar membrane
A structure that runs the length of the cochlea in the inner ear and holds the auditory receptors, called hair cells.
inhibition
A synaptic message that prevents a recipient neuron from firing.
high-throughput screening
A technique during which hundreds or thousands of compounds are tested to find those with the desired cellular effect. This process has been used to find therapies for neurodegenerative diseases. Because many of these diseases involve proteins that misfold and clump abnormally, lasers are used to measure whether proteins are clumped inside cells that have been robotically distributed into tiny containers, along with the small molecules to be tested. A machine then scans the containers and reports whether particular drugs have changed the protein clumping. Those drugs that are identified can then be tested further. New leads for drugs to treat Alzheimer's and prion disease have recently been described using this method.
amniocentesis
A technique of prenatal diagnosis in which amniotic fluid, obtained by aspiration from a needle inserted into the uterus, is analyzed to detect certain genetic and congenital defects in the fetus.
magnetic resonance spectroscopy (MRS)
A technique related to MRI — uses the same machinery but measures the concentration of specific chemicals, such as neurotransmitters — in different parts of the brain instead of blood flow. It also holds great promise: by measuring the molecular and metabolic changes that occur in the brain, this technique has already provided new information about brain development and aging, Alzheimer's disease, schizophrenia, autism, and stroke. Because it is noninvasive, it is ideal for studying the natural course of a disease or its response to treatment.
motor cortex
A thin, vertical strip at the back of the frontal lobe. Controls voluntary movements, sends signals to muscles. Top of the body is controlled by neurons at the bottom, vice versa.
axon
A threadlike extension of a neuron that carries nerve impulses away from the cell body.
combination antiretroviral treatment (CART)
A treatment which prevents the HIV virus from multiplying in the body. Cocktails of three or more drugs active against HIV.
drug addiction
A true brain disorder caused by drug abuse and the loss of control over drug intake or compulsive seeking and taking of drugs, despite the adverse consequences; it eventually alters the very structure and chemical makeup of the brain.
neural tube
A tube of cells running along the dorsal axis of the body, just dorsal to the notochord. It will give rise to the central nervous system.
diffusion tensor imaging (DTI)
A type of MRI procedure that assesses the path of fiber tracts in the brain; that is, the connectivity between regions. This technology takes advantage of diffusion rates of water, which tend to be higher along fiber tracts, to produce high resolution images of how areas may connect in the brain. Permits detailed images of the white matter tracts of fibres that connect brain regions.
procedural memory
A type of long-term memory of how to perform different actions and skills. Essentially, it is the memory of how to do certain things. Processed in basal ganglia and cerebellum.
experience-dependent plasticity
A type of plasticity in which changes in the brain are due to experiences that are not linked to specific ages and that vary across individuals and across cultures.
growth factor therapy
A type of treatment that, once the specific actions of molecules and their receptors are identified and their genes cloned, procedures can be developed to modify trophic factor-regulated functions in ways that might be useful in the treatment of neurological disorders. For example, copies of the factor might be genetically targeted to the area of the brain where this type of cell has died. The treatment may not cure a disease but could improve symptoms or delay the disease's progression. Researchers have also demonstrated that neutralizing molecules that stop or inhibit growth can help repair damaged nerve fiber tracts in the spinal cord.
glioma
A very malignant brain tumor. They release glutamate at toxic concentrations. The glutamate kills off neurons near the tumor, making room for its expansion. The released glutamate is largely responsible for the seizures, which originate from tissue surrounding the tumor.
orexin (hypocretin)
A wakefulness neurochemical (has 2 names). Produced in the lateral (feeding) and posterior (sympathetics) hypothalamus. Promotes wakefulness when the body is hungry or challenged by other homeostatic signals. Provides an excitatory signal to the arousal system, particularly to the norepinephrine neurons.
myelin sheath
A white, fatty extension of glia that wraps around the axons of some neurons that increases their communication speed.
artificial neural networks (ANNs)
AI system that attempts to mimic the neurons and synapses in the human brain. Are often used to study learning and memory. Usually they software on a conventional digital computer, they consist of a number of simple processing units that are highly interconnected in a network. Their ability to generalize to input patterns they have never been exposed to in training. They see relationships, capture associations and discover regularities in patterns. And they are fault - tolerant just like real brains. They can still retrieve a stored pattern even when the input pattern is noisy or incomplete
familial ALS
ALS transmitted to family members because of a gene defect.
memory molecules
AMPA and NMDA receptors
content-addressable storage
ANNs have this type of storage, in which information is stored in the weights of connections, the same way that synapses change their strength during learning.
basal ganglia
Abnormal brain activity where is found in Tourette's patients?
insomnia
Abnormal inability to sleep.
tuberous sclerosis complex
Abnormalities of the skin, seizures, kidney cysts and cardiac rhabdomyomas (benign tumor of striated muscle) are most consistent with this condition.
sodium/potassium ATPase
About two thirds of a neuron's energy is used to fuel these enzymes to recharges the ionic gradients of sodium and potassium after an action potential has occurred.
90%
About what percent of ganglion cells are very small?
50-80%
About what percent of the total energy consumption of the brain is consumed in the conduction of action potentials along nerve fibres and in synaptic transmission?
saltatory conduction
Action potentials can 'jump' from node to node, thus increasing the speed of conduction
amyotrophic lateral sclerosis (ALS)/Lou Gehrig's disease
Affects neurons that control voluntary muscle movements such as walking. For reasons that are not completely understood, motor neurons in the brain and spinal cord begin to disintegrate. Because signals from the brain are not carried by these damaged nerves to the body, the muscles begin to weaken and deteriorate from the lack of stimulation and resulting disuse. The first signs of progressive paralysis are usually seen in the hands and feet or in the muscles of speech and swallowing. Early symptoms include weakness in the legs, difficulty walking, clumsiness of the hands when washing and dressing, and slurred speech. Eventually, almost all muscles under voluntary control, including those of the respiratory system, are affected. Despite the paralysis, however, the mind and the senses remain intact. Death is usually caused by respiratory failure or pneumonia. Motor neurons die.
cognition
All the mental activities associated with thinking, knowing, remembering, and communicating.
alpha secretases
Amyloid-destroying enzymes that break up the amyloid peptide, preventing amyloid accumulation.
fluoxetine
An SSRI and an analog of serotonin that relieves symptoms of depression and of OCD.
ganglia
An anatomically distinct collection of sensory or motor neuron cell bodies within the PNS.
substantia nigra pars compacta
An area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons. Degeneration of neurons in this structure, which inhibits unwanted body movements, leads to the muscle tremors of Parkinson disease. The part of the basal ganglia with dopaminergic neurons. The loss of 40% of cells in this region account for symptoms in patients with Parkinson's.
horseradish peroxidase
An enzyme and chromogen injected and taken up by neurons that transport it in their axons and can be traced descending through the pons, medulla oblongata, and into the spinal cord.
acetylcholinesterase
An enzyme that breaks down the neurotransmitter acetylcholine.
cadherins
An important class of cell-to-cell adhesion molecules.
Ca2+
An ion in which the arrival of an action potential leads to the opening of its channels that activate enzymes that code for special proteins that directs neurotransmitters to bunch up into synaptic vesicles. NMDA receptors sense strong neuronal activity and send a signal to the neuron in the form of a surge of this ion. This ion surge is also brief, lasting for no more than about a second while glutamate is bound to NMDA receptors. However, it is a crucial molecule as it also signals to the neuron when NMDA receptors have been activated.
muscle
An organ composed of one of the three types of muscular tissue (skeletal, cardiac, and smooth), specialized for contraction to produce voluntary and involuntary movements of parts of the body; the body parts that produce movement under the control of the brain and spinal cord.
mitochondria
An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.
aqueductal gray matter
Animal experiments have revealed that electrical stimulation of brain areas such as this causes a marked elevation in the pain threshold and that this is mediated by a descending pathway from the midbrain to the spinal cord.
monoclonal antibodies
Antibodies produced by a single B cell that produces a single antigen in huge quantities; they are important in research and in treating and diagnosing brain tumors.
interferons
Antiviral proteins secreted by T cells
club drugs
Are synthetic psychoactive substances often found at "raves," and dance parties. They include GHB, MDMA (Ecstasy), ketamine, and methamphetamines.
parahippocampal region
Area that is most likely involved in visuospatial memory
optogenetic stimulation
Artificially inserted receptors sensitive to fiberoptic light pulses are inserted into certain brain regions to stimulate the firing of neurons and thus activate specific areas of the brain. Orexin activation plays a critical role in preventing abnormal transitions into REM sleep during the day, as occurs in narcolepsy.
H.M.
As a child, he developed a severe, difficult-to-treat form of epilepsy. When traditional therapies didn't help, he underwent an experimental surgical treatment — the removal of the medial regions of his temporal lobes. The surgery worked in that it greatly alleviated the seizures, but it left him with severe amnesia. He could remember recent events for only a few minutes and was unable to form explicit memories of new experiences. For example, after talking with him for a while and then leaving the room, upon returning, it would be clear that he had no recollection of the exchange.
slow-wave sleep (SWS)
As we fall asleep, the EEG becomes flatter at first but then, gradually, it shows increases in amplitude and decreases in frequency as we move through a series of discrete stages of sleep
40%
At what percent of cells must be lost before Parkinsonian symptoms occur, suggesting that perhaps the brain has a way of warding off symptoms.
growth cones
Axons are tipped with these, which cause them to be highly motile, allows them to explore the environment, determine the direction of growth, and guide the extension of the axon in that direction.
gray matter
Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.
dorsomedial nucleus
Brain structure activated by the subparaventricular nucleus. It activates the ventrolateral preoptic nucleus and the orexin neurons in the lateral hypothalamus to directly regulate sleep and arousal.
precuneous
Brain systems for past and future thinking. sulcus on medial surface of parietal lobe
dendrites
Branchlike parts of a neuron that are specialized to receive information.
amino acids
Building blocks of protein
multiplexed
By exploiting the very high speed of conventional electronics, the impulses from many silicon neurons can go through the process of carrying many different messages along the same wire. In this way, silicon engineers can begin to emulate the connectivity of biological networks.
dextroamphetamine
CNS stimulant for ADHD and also used to treat Tourette syndrome.
ion pumps
Carrier proteins that carry cations and anions across a plasma membrane. In neurons, these get rid of excess sodium.
adeno-associated virus (AAV) and lentivirus
Carries DNA as single-stranded DNA and can hold up to 5,000 base pairs. It does not make humans ill, infects dividing and non-dividing cells, can target specific cells, will integrate with the DNA of the host cell, and inserts into a specific region that does not harm humans 95% of the time. However, it requires a helper virus to replicate and fewer base pairs are transferred. These vectors are being used in clinical trials in patients with Parkinson's and in some rare genetic diseases.
shape of bars or edges and those at a particular angle (orientation)
Cells above and below the primary visual cortex's middle layer are stimulated by what?
progenitor cells
Cells that promote neurogenesis (transplanted stem cells)
chromosomes
Cellular structures carrying genetic material, found in the nucleus of eukaryotic cells. Each one consists of one very long DNA molecule and associated proteins. There are 23 pairs found in each cell.
Purkinje cell
Cerebellar neurons that play a major role in controlling the refinement of motor activities initiated by the frontal motor cortex
peptides
Chains of amino acids that can function as neurotransmitters or hormones. They are synthesized in the cell body and greatly outnumber the classical transmitters.
mutations
Changes in the nucleotide sequence of an organism's DNA, ultimately creating genetic diversity.
Angelman syndrome
Characteristics of this chromosomal abnormality are severe mental retardation, marked developmental delay, poor language skills, paroxysmal laughter, tongue thrusting, prognathism, seizures, abnormal gait and posturing.
attention deficit hyperactivity disorder (ADHD)
Characterized by excessively inattentive, hyperactive, or impulsive behaviors, this disorder affects an estimated 5 to 8 percent of school-age children. Studies show that as many as 60 percent of these children will continue to experience symptoms as adults. Children with this disorder are more likely to have problems in school, graduating from high school, maintaining a job, abusing drugs, or having healthy relationships. Symptoms of this disorder appear by middle childhood, last for six months or longer, and impair normal functioning to a significant degree in the following settings: for children — at school, among friends, and at home; for adults — at work and at home.
neurotransmitters
Chemical messengers released from nerve terminals that cross the synaptic gaps between neurons. When released by the sending neuron, they travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing whether that neuron will generate a neural impulse.
hormones
Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another
metabolism
Chemical reactions in living organisms that are necessary to maintain life
tastants
Chemicals that stimulate gustatory receptor cells
superoxide dismutase
Combats oxidative distress by inactivating superoxide by converting it to O2 and hydrogen peroxide. Helpful in treating ALS patients.
synaptic transmission
Communication between nerve cells at synapses.
phonological store
Component of the phonological loop of working memory that holds a limited amount of verbal and auditory information for a few seconds.
adenosine triphosphate (ATP)
Compound used by cells to store and release energy. Levels of this increase during sleep.
retina
Contains sensory receptors that process visual information and sends it to the brain. Part of the CNS and located at the back of the eye.
visual transduction
Conversion of light to neural signals by visual receptors.
unsuccessful ageing
Cortisol levels are higher in what type of ageing?
dorsal horn
Crescent shaped projection of gray matter within the spinal cord where sensory neurons enter the spinal cord, involved in the experience of pain.
secondary pathogenesis
Damage that occurs after an initial insult. Doctors attempt to prevent this in patients who have had a traumatic brain injury.
steroid hormones
Derived from and often chemically similar to cholesterol. Are lipids, hydrophobic, typically require a carrier protein in order to dissolve into the bloodstream.
head-direction cells
Discharge when an animal faces a particular direction. Cells discharge when the rat's head points in a given direction, irrespective of its location
metabotropic receptor
Do not have channels, but are coupled to G-proteins inside the cell-membrane that can pass on the message. These receptors don't contain ion channels, are not always localised in the region of the synapse and, most importantly, do not lead to the initiation of action potentials. We now think of these receptors as adjusting or modulating the vast array of chemical processes going on inside neurons
dopamine
Drugs that block what receptors are helpful in reducing the frequency and impact of schizophrenic symptoms?
electrical acupuncture machine
Electrical stimulation at one frequency of vibration triggers the release of endogenous opioids called endorphins, such as met-enkephalin, while stimulation at another frequency activates a system sensitive to dynorphins. Used instead of drugs
dynorphins
Endogenous opioid, modulate pain, emotion, attachment, feeding, act on kappa receptors
aspartate
Excitatory neurotransmitter, works with glutamate
spina bifida
Failure of the neural tube to close results in this condition, that is usually confined to the lower spinal cord. While distressing, it is not lifethreatening.
ionotropic receptors
Fast acting, short lasting, receptor IS an ion channel, opens when neurotransmitter binds ("lock and key"). They have a channel through which ions pass (such as Na+ and K+). The channel is made up of five sub-units arranged in a circle.
muscle spindles
Fibers that are sensitive to change in length of muscle and rate of that change, major sensory organs of muscle. Parallel to muscle fibers. Transmits signal to CNS when stretched. Causes muscle to contract to prevent overstretching/ stretching too fast. Involved in the reflexive knee movement.
Parkinson's disease
First-generation antipsychotics mimicked what disease?
parietal neglect
Following right parietal damage, many patients ignore the left visual field. This happens because the right parietal lobe holds a map for both sides of space, but the left parietal only represents only the right visual field.
macrophages
Found within the lymph nodes, they are phagocytes that "eat" and destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.
Pacinian and Meissner corpuscles
From these and similar experiments in anaesthetised animals, we now know that these touch receptors adapt quickly and so respond best to rapidly changing indentations (sense of vibration and flutter).
mirror neurons
Frontal lobe neurons that fire when performing certain actions or when observing another doing so. The brain's mirroring of another's action may enable imitation, language learning, and empathy.
nodes of Ranvier
Gaps in the myelin sheath of the axons of peripheral neurons. Allows for saltatory conduction.
informed consent
Giving the patient adequate information concerning the method, risk and consequences to a specific procedure, it's risks, expected outcome and alternatives.
endocrine glands
Glands of the endocrine system that release hormones into the bloodstream
gonads
Glands related to sexual characteristics and the processes involved in reproduction
transporters
Glia have these miniature vacuum cleaners whose job is to suck up the transmitter in the cleft. This clears the chemical messengers out of the way before the next action potential comes. But nothing is wasted - glial cells then process the transmitter and send it back to be stored in the storage vesicles of the nerve endings for future use.
AMPA
Glutamate-activated ionotropic receptors that are fast and let sodium into the cell; involved in memory.
Colin Blakemore
He has contributed to understanding how the visual system develops. This includes pioneering studies using cell-culture to study interactions between different parts of a pathway in the embryonic brain.
high GR receptor
Highly concentrated in hippocampus, as cortisol levels begin to rise, particularly in the morning, this receptor becomes progressively more occupied.When we become stressed, cortisol levels become very high indeed, activation of this receptor is sustained and the hippocampus is then shut down by a genetically controlled program.
low MR receptor
Highly concentrated in hippocampus. This is activated by the normally circulating levels of cortisol in the bloodstream highway of the HPA axis. This keeps our general metabolism and brain processing ticking over nicely.
follicle-stimulating hormone (FSH)
Hormone responsible for ovulation
somatostatin
Hormone that inhibits release of growth hormone and insulin. A reduction of this hormone is found in Alzheimer's patients.
circulating molecules
How does the brain receive signals from injured or infected tissues humoral in origin?
C fibers and vagus nerve
How does the brain receive signals from injured or infected tissues neural in origin?
100 m/s
How fast can action potentials travel in myelinated neurons?
3.2 million kilometers
How long is the wiring of the brain?
6
How many cortical areas are there?
5
How many drugs have been approved by the FDA to treat Alzheimer's?
4-6
How many episodes of REM sleep do we have?
8
How many hours should we sleep?
1,600
How many norepinephrine neurons are in the brain?
44
How many phonemes are in English?
4
How many stages of REM are there?
1 quadrillion
How many synapses does the brain have?
10 watts
How much energy does the brain consume?
10 megawatts
How much energy would it cost to build a synthetic brain?
grandmothered
How to call a machine which had the process of over-trained networks that would end up responding only to one type of input (without making error)?
20 nanometres
How wide are synapses?
neuroimmunology
However, this view of the brain as privileged has changed dramatically over the last decade as the result of research on brain-immune system interactions. ______is now a very active area of research.
perceptual representation
Identification of words and objects based upon their form and structure
free-run
If a human being is completely isolated from environment and has no clues about the time of day the period of circadian oscillation will usually lengthen slightly. May vary slightly from person to person.
Mg2+
If the synapse is activated quite slowly, the NMDA receptors play little or no role. This is because as soon as NMDA receptors open their ion channels these channels become plugged by this ion. But, when synapses are activated by several pulses very quickly to a set of inputs on to a neuron, the NMDA receptors immediately sense this excitement and dispel these ions.
computed tomography (CT)
Imaging technique achieved by rotating an x-ray emitter around the area to be scanned and measuring the intensity of transmitted rays from different angles.
stem cell
Immature (uncommitted) cells with the potential to develop into almost any type of cell.
azathioprine
Immunosuppressant used to possible dampen down certain parts of the immune system in pateints with MS.
gamma particles
In PET, rings of detectors around the subject's head record the timing and position of these particles emitted by the nuclear isotope as it traverses the brain and decays.
nodes of Ranvier
In a myelinated neuron, where does it concentrate its ion channels?
Eric Kandel
In his work on learning and memory, this Nobel Laureate began his investigations using the sea slug and was successful in uncovering how short- and long-term memories are retained. He found that certain stimuli resulted in a more robust protective reflex, a form of learning for the sea slug. Furthermore, the strengthened reflex could remain in place for days and weeks as a short-term memory. Additional work showed that a stronger synapse was responsible for the retention of this information. Long-term memories form in a different way. Stronger stimuli activate genes, resulting in an increase of some proteins and a decrease in others. These changes ultimately lead to the growth of new synapses. After demonstrating that both short- and long-term memory in sea slugs involve the synapse, he was able to illustrate that similar mechanisms are at work in mice and other mammals.
"fight or flight" response
In response to impending danger, muscles are primed, attention is focused, and nerves are readied for action. The initial tingling sensation, sweating, heightened awareness, rapid pulse rate, higher blood pressure and general feelings of fear are symptoms. Epinephrine and norepinephrine.
ascending system
In this pain system, impulses are relayed from the spinal cord to several brain structures, including the thalamus and cerebral cortex. These structures are involved in the process by which pain or itch messages become a conscious experience. The experience of pain or itch is not just a function of the magnitude of the injury or even the intensity of the impulse activity generated. Other factors, such as the setting in which the injury occurs (e.g., in childbirth or in a car accident), as well as the emotional impact, also determine our overall response to the experience.
stage 3
In this stage of sleep, deep, slow brain waves known as delta waves begin to emerge during this stage. It is a transitional period between light sleep and a very deep sleep.
stage 2
In this stage of sleep, you see sleep spindles and K complexes on the EEG. It occupies the most time during sleep. Grinding of the teeth occur, and the stage is characterized by theta waves.
generalized epilepsy
In this type of epilepsy, seizures typically result in loss of consciousness and can cause a range of behavioral changes, including convulsions or sudden changes in muscle tone. They occur when there is simultaneous excessive electrical activity over a wide area of the brain, often involving the thalamus and cerebral cortex. They are often readily controlled by antiepileptic drugs, with up to 80 percent of patients seizure-free with treatment. The normal alpha rhythym of the electroencephalogram (EEG) is replaced by large, slow, synchronous waves of electrical activity in both cerebral hemispheres .
receptive field
In vision, the portion of the retina that, when stimulated, causes the activity of higher order neurons to change. Activated when light hits a tiny region in the center of the field and inhibited when light hits the area surrounding the center.
compartments
Inside of neurons, these consist of proteins, mostly manufactured in the cell body, that are transported along the cytoskeleton
sodium channels
Ion channels opened during an action potential; voltage-gated. These channels are key targets of local anesthetics.
NOMAD
Is a fidgety yet thoughtful progenitor of thinking machines to come. It stands 2-feet tall with a cylindrically-shaped torso, it has "eyes", "ears", gripper "arms" and other sensors to help it navigate. What makes it different from most robots is that it operates without coded instructions or rules. Instead, it has a computer-simulated brain with 10,000 simulated brain cells and more than a million connections among them to perceive and react to its environment. It can handle novel situations and learn from its mistakes, as it wanders around in a pen scattered with small painted cubes.
semaphorin
Is one signaling molecule candidate that may be involved in the degeneration of neurons in ALS. Causes chemorepulsion in axonal guidance,
150
It has been shown that for a network of 1000 units, about how many patterns can be retrieved before errors in the retrieval patterns become too large?
autoassociative network
It is actually a more generic term that refers to all memories that enable one to retrieve a piece of data from only a tiny sample of itself. Traditional memory stores data at a unique address and can recall the data upon presentation of the complete unique address. They are capable of retrieving a piece of data upon presentation of only partial information from that piece of data.
declarative memory
It refers to memories which can be consciously recalled such as facts and events.
somatosensory cortex
It was found that during changes in experienced pain intensity there was activation of this cortex?
release of calcium ions into synapse, activation of cAMP, activates enzymes and CREB, changes genes in the nucleus to produce proteins, strong synapse.
LTP pathway
basal ganglia
Large clusters of neurons, located above the thalamus and under the cerebral cortex, that work with the cerebellum and the cerebral cortex to control and coordinate voluntary movements.
cerebellum
Later on, particularly if complex movements become habitual, the system free-runs without the dopamine reward. At this point, particularly if movements have to be accurately timed, the _______ starts to play a role
fetal alcohol syndrome
Leading preventable cause of mental retardation. A medical condition in which body deformation or facial development or mental ability of a fetus is impaired because the mother drank alcohol while pregnant.
parietal apraxia
Lesions in the left parietal lobe, esp. the supramarginal gyrus (junction of parietal and temporal lobe, near Wernicke's) - typically shows apraxia in both hands - command to do something isn't reaching the execution system
cornea
Light passes clear membrane at the front of the eye covering the iris, pupil, and anterior chamber. Responsible for 60% of the eyes focusing power. Contains 5 layers.
endocannabinoids
Lipid-derived messengers sometimes referred to as the brain's marijuana. These messengers control the release of neurotransmitters, usually by inhibiting them, and can affect the immune system and other cellular parameters. These also play an important role in the control of behaviours.
cerebrospinal fluid (CSF)
Liquid that nourishes the brain, makes it lighter, transports waste, and travels around brain and under skull through ventricular system
cataplexy
Loss of muscle control with intrusion of REM sleep during waking hours, usually caused by an emotional trigger most commonly found in narcoleptics.
schizophrenia
Marked by disturbances in thinking, cognition, emotional reactions, and social behavior, this mental disorder usually results in chronic illness and personality change. Delusions, hallucinations, and thought disorder are common, as are disturbances in attention, memory, and complex thinking. The disorder leads to changes that may be caused by the disruption of neurodevelopment through a genetic predisposition, which may be exacerbated by environmental factors such as maternal infections or direct brain trauma. The disorder usually is diagnosed between the ages of 15 and 25. Few patients recover fully following treatment, and most continue to have moderate or severe symptoms that may be aggravated by life stressors. Deficits in cognition are frequent, lifelong manifestations in most patients, even those who show good recovery from more acute "positive" symptoms, such as hallucinations, delusions, and confused thinking. "Negative" symptoms, such as inability to experience pleasure and lack of motivation, may be the most debilitating part of the disorder. These symptoms make it difficult for many people to lead productive lives. Unfortunately, many of these symptoms are generally resistant to drug treatment. The ventricles of the brain enlarge in the condition, and the activity of the frontal lobes becomes impaired.
synaptic vesicles
Membrane-bounded compartments in which synthesized neurotransmitters are kept. Reform when their membranes are swallowed back up into the nerve ending where they become refilled with neurotransmitter, for subsequent regurgitation in a continuous recycling process.
Alzheimer's disease (AD)
Most common form of dementia. Earliest symptoms include forgetfulness; disorientation as to time or place; and difficulty with concentration, calculation, language, and judgment. As the disease progresses, some patients have severe behavioral disturbances and may even become psychotic. In the final stages, the affected individual is incapable of self care and becomes bedridden. Patients usually die from pneumonia or some other complication of immobility. A progressive, irreversible brain disorder/type of dementia characterized by gradual deterioration of memory, reasoning, language, and eventually physical function. Progressive degeneration of the brain with abnormal protein deposits. Acetylcholinesterase inhibitors are used to slow the progression of this dementia. Can be caused by an overproduction of cytokines. Brain cells die: the cortex thins and the ventricles (the fluid filled spaces in the brain) enlarge. However, genetic factors do not tell the whole story: environmental factors, such as toxins and other insults such as traumatic brain injury, may also play an important role.
methylphenidate
Most common medication for ADHD and also used to treat Tourette syndrome.
cones
Most of our vision comes from these photoreceptors that work under most light conditions and are responsible for acute detail and color vision. The human eye contains three types of these (red, green and blue)
magnocellular (M-type) cells
Motion is detected by these cells because they have very high temporal resolution. However, these cells have low spatial resolution, so much of the rich detail of an object can no longer be seen once it is motion. These cells therefore provide a blurry but moving image of an object. Abnormalities in these cells may underlie certain cases of dyslexia.
ibuprofen and naproxen
NSAIDs
pons
Name the area of the cerebral cortex with the function described: • Important for REM sleep; origin of norepinephrine pathway. A hindbrain structure that connects the medulla to the two sides of the cerebellum; helps coordinate and integrate movements on each side of the body
Rett syndrome
Neurodevelopmental disorder of childhood characterized by normal early development followed by loss of purposeful use of the hands, distinctive hand movements, slowed brain and head growth, gait abnormalities, seizures, and mental retardation; affects females almost exclusively; included in autism spectrum disorders.
motor cortex
Neurons in which region degenerate in ALS?
basal ganglia
Neurons in which region degenerate in Huntington's?
interneurons
Neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs.
met-enkephalin
Neuropeptide: generally inhibitory and looks like morphine
effective connectivity
New mathematical techniques are also being developed to look at how the neural activity of different brain regions interacts and correlates during complex tasks. This measure allows us to appreciate how brain areas work as a team and not merely as isolated functional hot spots.
emergent properties
New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.
flexion withdrawal reflex
Noxious stimulus to one leg causes withdrawal of the stimulated leg, such as stepping on a sharp object.
ectoderm
One of the three primary (embryonic) germ layers formed during gestation. It ultimately forms external structures such as the skin, hair, nails, and inner linings of the mouth and anus, as well as the entire nervous system.
mesoderm
One of the three primary (embryonic) germ layers formed during gestation. it ultimately forms 'middle' structures such as bones, muscles, blood vessels, heart, kidneys, etc. This structure releases molecules that turn on certain genes and turn off others, triggering some ectoderm cells to become nerve tissue
activity-dependent refinement
Only about half of the neurons generated during development survive to function in the adult. Entire populations of neurons are removed by apoptosis, programmed cell death, in this process.
last great frontier
Our efforts to understand the nature of mental disorders represents this for medical neuroscience.
descending system
Pain messages can be suppressed by systems of neurons that originate within the gray matter in the brainstem. These systems suppress the transmission of pain signals from the dorsal horn of the spinal cord to higher brain centers. Some of these use naturally occurring chemicals, the endogenous opioids, or endorphins, which are functionally similar to morphine. Recent findings indicating that endorphins act at multiple opioid receptors in the brain and spinal cord have had important implications for pain therapy. For example, scientists began studying how to deliver opioids into the spine after discovering a dense distribution of opioid receptors in the spinal cord horn.
Parkin
Parkinson's disease is due to problems in genes coding for this protein.
amnesia
Partial or total loss of memory
panic disorder
Patients experience an overwhelming sense of impending doom, accompanied by sweating, weakness, dizziness, and shortness of breath. With repeated attacks, patients may develop anxiety in anticipation of another attack. As a result, people may avoid public settings where attacks might occur. If these individuals are untreated, they may develop agoraphobia and become virtually housebound. Antidepressants, including SSRIs, are effective, as is cognitive behavioral therapy.
bipolar disorder (manic depressive illness)
Patients with this disorder experience episodes of deep depression and manic highs. Many patients return to normal moods in between acute episodes, but a large number continue to have troubling symptoms, usually of depression. They also have an increased risk of suicide. The depressive episodes are indistinguishable from those of a major depression and are characterized by sad mood, loss of interest, lack of energy, disturbances of sleep and appetite, difficulty concentrating, feelings of hopelessness and worthlessness, suicidal thoughts, and sometimes suicidal acts.
obsessive-compulsive disorder (OCD)
People with this disorder become trapped, often for many years, in repetitive thoughts and behaviors, which they recognize as groundless but cannot stop. Such behavior includes repeatedly washing hands or checking that doors are locked or stoves turned off. The illness is estimated to affect 2.2 million American adults annually. One-third of adults develop their symptoms as children. Neuroscientists think that environmental factors and genetics probably play a role in the development of the disorder. Positron emission tomography (PET) scans reveal abnormalities in both cortical and deep areas of the brain, implicating central nervous system changes in individuals with this disorder.
rods
Photoreceptors extremely sensitive to light and allow us to see in dim light, but they do not convey color. They constitute 95 percent of all photoreceptors in humans
acute phase proteins
Plasma proteins produced early in infection in response to early alarm mediators such as macrophage derived interleukin 1 which is released as a result of tissue injury. Their concentration rises day 4 - 10 and results in the patient experiencing symptoms. Cytokines influence the production of these in the liver.
insular cortex
Primary cortical processing area for taste. The part of the cortex that first receives taste and pain information.
apoptosis
Programmed cell death
Viral Tat
Proteins released by infected HIV cells linked to the neurotoxicity found in patients with HAND.
magnocellular system
Provides info about movement, depth and very subtle differences in brightness in the scene before our eye. Plays a crucial part in helping to point the eyes steadily at each letter in turn, and hence in determining their order. Provides a particularly large input to the cerebellum
magnetic resonance imaging (MRI)
Providing a high-quality, three-dimensional image of organs and structures inside the body without X-rays or other radiation, these devices are noninvasive and unsurpassed in the anatomical detail they show. They tell scientists when structural abnormalities first appear in the course of a disease, how they affect subsequent development, and precisely how their progression correlates with mental and emotional aspects of a disorder. In some instances, they can even reveal minute changes that occur over time. During the 15-minute procedure, a patient lies inside a massive, hollow, cylindrical magnet and is exposed to a powerful, steady magnetic field. Different atoms in the brain resonate to different frequencies of magnetic fields. A background magnetic field lines up all the atoms in the brain. Then a second magnetic field, oriented differently from the background field, is turned on and off many times a second; at certain pulse rates, particular atoms resonate to and line up with this second field. When the second field is turned off, the atoms that were lined up with it swing back to align with the background field. As they swing back, they create a signal that can be picked up and converted into an image. Tissue that contains a lot of water and fat produces a bright image; tissue that contains little or no water, such as bone, appears black.
anxiety disorders
Psychological disorders characterized by distressing, persistent anxiety or maladaptive behaviors that increase anxiety.
neuroimaging
Refers to a set of techniques that allows researchers to make detailed maps of the human brain and assign functions to particular regions in the brain. Can be used as a polygraph.
redundancy
Refers to storing the same field in more than one location in a database.
growth factors
Regulatory proteins that are taken up inside and then transported to the cell body where they influence the expression of neuronal genes and hence the manufacture of new proteins. These enable the neuron to grow longer dendrites or make yet other dynamic changes to its shape or function. Information, nutrients and messengers flow to and from the cell body all the time.
1,000
Rods are about how many times more sensitive to light than cones.
polarization
Roughly speaking, the dendrite receives, the cell-body integrates and the axons transmit.
sertraline and paroxetine
SSRI's used for treating OCD.
enkephalin
Scientists made their first discovery of an opiate peptide produced by the brain. This chemical resembles morphine, an opium derivative used medically to kill pain.
post-traumatic epilepsy
Seizures occurring within a year of head injury.
neuralgia
Sharp pain along the course of a nerve or several nerves; nerve pain or numbness.
unmyelinated C fibers
Slow pain sensation is transmitted primarily by these fibers.
neurotrophins (trophic factors)
Small proteins in the brain that are necessary for the development, function, and survival of specific groups of neurons. Made in brain cells.
Golgi tendon organs
Small stretch receptors located in the tendons that detect the force applied by a contracting muscle, allowing the brain to sense and control the muscular force exerted during movement. They help to protect muscles and tendons from damage by inhibiting muscle contraction
touch receptors
Specialized sensory neurons under the skin's surface that detect pressure, texture, temperature, or vibrations against the skin
V5 (MT)
Specialized to motion detection. Horizontally even with V4, but in the anterior axillary line.
second messengers
Substances that induce chemical changes within a neuron just after the neuron receives a neurotransmitter message and just before it responds. They are also thought to play a role in the manufacture and release of neurotransmitters and in intracellular movements and carbohydrate metabolism in the cerebrum.
clock proteins
Suprachiasmatic cells express these proteins to regulate the body's circadian rhythm.
Tourette syndrome
Symptoms usually appear between the ages of four and eight, but in rare cases may emerge in the late teenage years. The symptoms include motor and vocal tics — repetitive, involuntary movements or utterances that are rapid, sudden and persist for more than one year. The types of tics may change frequently and increase or decrease in severity over time. In roughly one-half of individuals, this disorder lasts a lifetime, but the remaining patients may experience a remission or decrease in symptoms as they get older. A high percentage of people with this syndrome also have associated conditions, such as problems with learning, difficulties with attention, obsessive thoughts and compulsive rituals. Often these manifestations are more troublesome to individuals than the tics themselves, so physicians must consider them when choosing a treatment regimen. The syndrome is inherited and seems to result from abnormal activity in the basal ganglia. Research suggests that genes associated with the syndrome, perhaps together with in utero or early environmental conditions, cause abnormalities in basal ganglia development or excesses in certain chemicals, including dopamine.
1/1000 sec
Synaptic transmission is a very rapid process: the time taken from the arrival of an action potential at a synapse to the generation of an epsp in the next neuron is very rapid.
animal experiments
Testing on animals, either for medical or cosmetic purposes, to ensure that the product is safe for use by humans
long-term depression (LTD)
The acquisition of skilled movements depends on this cellular learning mechanism, which reduces the strength of some synaptic connections.
pupil
The adjustable opening in the center of the eye through which light enters.
macula
The area around the fovea that is critical for reading and driving
cyclic adenosine monophosphate (cAMP)
The bi-product of ATP being broken down by the Adenylyl Cyclase enzyme. This second messenger effects ion channels in the membrane and changes the expression of genes in the nuclei
blood brain barrier
The brain is protected from harmful chemicals in the blood stream by thicker walls surrounding the brains blood vessels.
cortical areas
The brain regions important for the long-term storage of knowledge about facts and events and for how this knowledge is used in everyday situations.
ventricular zone
The cells that form the central nervous system originate from this structure (inner surface)
depolarisation
The change from a negative resting potential to a positive action potential (caused by opening of sodium channels)
reward system
The circuit normally involved in an important type of learning that helps us stay alive. It evolved to mediate the pleasurable and motivating effects of natural rewards, such as eating when we are hungry or drinking when we are thirsty. Indeed, when a reward produces feelings of pleasure, we learn to repeat the actions that got us the reward in the first place. Drugs can activate this same system, thus promoting continued drug use.
binocular rivalry
The competition between the two eyes for control of visual perception, which is evident when completely different stimuli are presented to the two eyes
Pick's disease
The degenerative disease of the frontal and temporal cortex that spares parietal and occipital lobes. Presents with behavioral and language symptoms that arise early with progression to dementia
pattern formation
The development of a multicellular organism's spatial organization, the arrangement of organs and tissues in their characteristic places in three-dimensional space.
1950s-1960s
The discovery in the late ___ that the level of dopamine was decreased in the brains of Parkinson's patients was followed in the ___ by successful treatment with the drug levodopa.
tympanic membrane
The eardrum. A structure that separates the outer ear from the middle ear and vibrates in response to sound waves.
electro-myographic recordings (EMGs)
The electrical events in the muscles of the arm can be recorded with an amplifier, even through the skin, and these recordings can be used to measure the level of activity in each muscle.
endoderm
The embryonic germ layer that gives rise to the viscera, the digestive tract, and other internal organs
pituitary gland
The endocrine system's most influential gland. Under the influence of the hypothalamus, it regulates growth and controls other endocrine glands.
adenyl cyclase
The enzyme found inside cells, associated with hormone receptors, that converts ATP to cAMP.
chlorpromazine
The first antipsychotic drug, discovered by accident in the 1950s, was shown to reduce symptoms of schizophrenia. Clinical trials demonstrated that it was more effective than a placebo or a sedative. Subsequently, more than 20 effective antipsychotic drugs were developed.
body defense
The first is locally within the tissue that is infected, injured or inflamed, causing swelling, pain, changes in blood flow and release of local inflammatory molecules. More generally, activation of the immune system triggers cells called leucocytes and macrophages, and acute phase proteins that travel to the site of attack, to identify, kill and then remove invading pathogens.
bupropion
The first non-nicotine prescription drug, it is an antidepressant and has been approved for use as a pharmacological treatment for nicotine addiction.
anandamide
The first-to-be-isolated endocannabinoid that binds to THC receptors.
estradiol
The granulosa cells of developing follicles secrete this hormone.
hair cells
The hairlike sensory receptors for sound, which are embedded in the basilar membrane of the cochlea.
cognitive engineering
The idea is to take advantage of what has been learned about how information is encoded, stored, consolidated (the 'fixing' process) and then retrieved. Paying attention, spacing out learning sessions, and getting frequent reminders to help the 'fixing' process are all examples. Some elderly patients with memory problems are finding a paging system called "NeuroPage" quite helpful - it reminds them of what they should be doing next and so helps them structure their day in a manner that they might otherwise forget to do.
sparse coding
The idea that a particular object is represented by the firing of a relatively small number of neurons. Provides another important design principle for engineers building artificial neural networks.
canonical cortical microcircuit
The intricate circuitry of the visual cortex is one of the great puzzles that has preoccupied neuroscientists. Some neuroscientists suggest that there is a __________________ like chips of computer in the cortical layers connection.
cerebral cortex
The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center. Contains "gray matter" because it lacks myelin. Folded into grooves to increase the surface area of the brain. Most knowledge about facts and events are stored here.
imprinting
The learning process by which certain animals form attachments during a critical period very early in life.
photoreceptors
The light-sensitive cells in the retina that converts light to electrical signals - the rods and cones. There are about 125 million in each eye.
stereocilia
The long microvilli attached to hair cells that aid in converting mechanical signals to electrical ones.
orbital cortex
The major site where the multiple factors for flavor are combined
ventral tegmental area
The major source of dopaminergic projections in the pleasure circuit of the rat and human; where the dopamine systems start and end in the brain. It communicates directly with the nucleus accumbens.
stapes
The middle ear ossicle resembling a stirrup that transmits the vibratory motion from the incus to the oval window.
Huntington's disease
The most common hereditary brain disorder?
1,000
The most efficient axons can conduct action potentials at frequencies up to how many times per second?
catecholamines
The neurotransmitters dopamine, epinephrine, and norepinephrine, which are active in both the brain and the peripheral sympathetic nervous system. These three molecules have certain structural similarities and are part of a larger class of neurotransmitters known as monoamines. Current ADHD medications target these.
anterior cingulate cortex and insular cortex
The pain pathway projects to these brain areas.
mammillary bodies
The part of the brain plays a role in memory and is implicated in Korsakoff's. The pair of hypothalamic nuclei, one on the left and one on the right, that are part of a system that plays an important role in emotion; they are visible on the inferior surface of the hypothalamus as a pair of bumps just behind the pituitary.
exome
The portion of the genome that actually codes for DNA.
neural induction
The process by which signaling molecules are released by the mesoderm. These molecules turn on certain genes and turn off others, triggering some ectoderm cells to become nerve tissue in this process
social cognition
The process of analyzing and interpreting events, other people, oneself, and the world in general.
primary visual cortex (striate cortex)
The region of the cerebral cortex that receives information directly from the visual system; located in the occipital lobe
tumor grade
The severity of a tumor. The degree of cellular differentiation based on histologic appearance of tumor. Usually graded I-IV based on degree of differentiation and number of mitoses per high-power field; character of tumor itself.
feedforward associator
The simplest form of ANN, which has layers of interconnected input and output units. An associative memory is encoded by modifying the strengths of the connections between the layers so that, when an input pattern is presented, the stored pattern associated with that pattern is retrieved.
neuroendocrinology
The study of interactions between the nervous system and the endocrine system
electrophysiology
The study of the electrical properties of neurons. Used to study the human brain and even to diagnose some conditions, such as hearing loss.
phonology
The study of the patterns and distributions of speech sounds in a language and the tacit rules for their pronunciation.
hypnagogic hallucination
The term used to refer to the vivid dream-like perceptions that may occur during an episode of sleep paralysis in patients with narcolepsy.
endothelial cells
The thin layer of cells that line the interior surface of all blood vessels. Only one cell thick in capillaries.
<1 millisec
The time it takes for a synpatic vesicle to refill by traveling to the postsynaptic neuron.
Merkel's disk
The touch receptor that responds well to a sustained indentation of the skin (sense of pressure).
Ruffini endings
The touch receptors that respond to slowly changing indentations.
meridians
The traditional Chinese medicine concept of channels through which qi, blood, and information flow to all parts of the body
lens
The transparent structure behind the pupil that changes shape to help focus images on the retina.
Chicks and frogs
Their large embryos allow microsurgical manipulations - such as examining what happens when cells are moved to abnormal positions.
eye movement desensitization and reprocessing therapy
Therapy technique in which the client holds a vivid mental image of a troubling event or situation more rapidly moving his or her eyes back-and-forth in response to the therapist waving a finger or while the therapist administers some form of bilateral stimulation. Used to treat PTSD.
evolutionary ethics
There is an emerging awareness that morality and conscience are closely coupled to the emotional brain that processes signals of reward and punishment
rabbits and cats
These animals are researched for studies of vision and other senses.
rats and mice
These animals are researched to discover the role of neurotransmitters in cell communication. The advances in medicine that led to the type of treatment of Parkinson's disease and ADHD were made possible by studies using them.
place cells
These are neurons in the hippocampus that fire action-potentials only when an animal explores a familiar place. Different cells code for different parts of the environment such that a population of cells is involved in mapping a whole area. Other cells in a nearby brain area code for the direction the animal is moving in. The two areas working together - the map of space and the sense of direction - help the animal learn to find its way around the world.
cytokines
These are the body's retaliators. There are now well over 100 of them - and more are being discovered all the time. These proteins are normally produced in the body at very low levels, but are switched on quickly in response to disease or injury. They include interferons, interleukins, tumour necrosis factors and chemokines. Many are produced locally within damaged tissues and act on cells nearby, but some enter the blood stream where they send signals to distant organs including the brain. It is these that cause most of the responses to disease and infection. The triggers for their production include bacterial or viral products, damage to cells or threats to cell survival such as toxins or low levels of oxygen. Another important regulator of these productions is the brain that, through neural signals to tissues (mainly via the sympathetic nervous system) or hormones (such as cortisol from the adrenal gland), can switch them on or off. These are secreted viral products or cell coded signal molecules hypothesized to be related to an indirect effect of HIV infection in patients with HAND.
opioids
These are the most potent painkillers and are used for severe pain. They, however, have many adverse side effects, such as respiratory depression and constipation, and in some individuals they have a high potential for abuse. These act primarily in the central nervous system, blocking the transfer of pain signals from the spinal cord to the brain. Examples include morphine and codeine.
colliculi
These collections of neurons in the midbrain play a critical role in visual and auditory reflexes and in relaying this type of information to the thalamus. The "hills of the midbrain".
antiepileptic drugs (anticonvulsants)
These drugs are used to treat seizures and headaches. They target either ion channels or neurotransmitter receptors. They are useful primarily for neuropathic pain. Such pain includes the pain from diabetic neuropathy; neuralgia; phantom limb pain; and post-stroke pain. Examples include gabapentin and topiramate.
nonsteroidal antiinflammatory drugs (NSAIDs)
These drugs are useful for treating mild or moderate pain, such as headache, sprains, or toothache. Because they are anti-inflammatory, they also are effective for treating injuries or conditions such as arthritis and postoperative pain. They work by inhibiting the COX enzymes that make prostaglandin. Examples include ibuprofen and naproxen.
triptans
These drugs are very effective at stopping a migraine headache in its tracks.
antidepressants
These drugs combat symptoms of depression. They are useful primarily for neuropathic pain. Such pain includes the pain from diabetic neuropathy; neuralgia; phantom limb pain; and post-stroke pain. The best results have been reported with these drugs that regulate both serotonin and norepinephrine. Examples include amitriptyline and duloxetine.
Drosophila melanogaster (fruit flies)
These insects are used as part of studies in visual transduction. Clock proteins are studied in this species by scientists. This animal is researched to learn more about the human nervous system. Also used in developmental neuroscience
skeletal muscles
These muscles are attached to bones and are characterized by discontinuous voluntary contraction, multinuclear striated unbranched fibers, actin and myosin overlapping for banding pattern, triadic T tubules, troponin and desmin as Z disc intermediate filament.
optical imaging
These techniques rely on shining weak lasers through the skull to visualize brain activity. They are inexpensive and relatively portable. They are also silent and safe: because only extremely weak lasers are used, these methods can be used to study everyone, even infants.
interactionist neuroscientists
They argue for a more eclectic approach to modern neuroscience, an approach that explores its interaction with the social sciences as well. These are not issues easily discussed in a public forum, but questions about what sorts of research should be undertaken are matters about which society should be consulted.
integrate-and-fire neurons
They get this name because they 'add up' the weighted inputs, coded as voltages that are arriving at their synapses, and only 'fire' an action potential if the voltage reaches a set threshold.
cold, warmth, pain
Thin axons with "naked" endings transmit which sensations rather slowly?
mouse
This animal breeds rapidly - its genome has been mapped and almost completely sequenced.
zebrafish
This animal is researched to learn more about developmental neuroscience. The embryo is transparent - allowing each cell to be watched under the microscope as it develops.
prefrontal cortex
This brain region has been implicated in planning complex cognitive behavior, personality expression, decision making, and moderating social behavior. The region of the brain responsible for predicting the consequence of events or actions.
recurrent neural net
This consists of a single layer where every unit is interconnected and all the units act as input and output. It sounds a bit strange, but this design enables the net to store patterns rather than merely pairs of items.
Huntington's disease
This disease affects both the basal ganglia, which controls coordination, and the brain cortex, which serves as the center for thought, perception, and memory. The most recognizable symptoms include involuntary jerking movements of the limbs, torso, and facial muscles. These are often accompanied by mood swings, depression, irritability, slurred speech, and clumsiness. As the disease progresses, common symptoms include difficulty swallowing, unsteady gait, loss of balance, impaired reasoning, and memory problems. Eventually, the individual becomes totally dependent on others for care, with death often due to pneumonia, heart failure, or another complication. Cause has been linked to the degeneration of GABA-producing neurons, which leads to uncontrollable behavior. Chromosome 4 is altered.
marijuana
This drug distorts perception and alters the sense of time, space, and self. In certain situations, it can produce intense anxiety. Users have poor short-term memory and problems processing complex information.
cortisol feedback to the brain
This is a process. The highest density of cortisol receptors is in the hippocampus, a key structure for learning and memory, but cortisol also acts on the amygdala, which processes fear and anxiety. The net effect is to turn on the amygdala - to allow learning of fear-related information; and to turn off the hippocampus - to ensure that resources are not wasted on more complex but unnecessary aspects of learning. Cortisol is focus juice.
localized pressure
This is caused by blood leaks from vessels coming into direct contact with brain tissue. Afterwards, cerebral blood flow is reduced.
headache
This is caused by muscle tension and is nothing serious to worry about. Very occasionally - especially if it comes on very quickly, or is associated with a skin rash or with vomiting - there can be a serious underlying cause. In these conditions the pain comes not from the brain itself, but from irritation or stretching of the meninges - the lining of the brain.
carbidopa
This is combined with L-dopa, inhibits DOPA decarboxylase (active only peripherally) which allows lower effective doses of L-dopa and allows for fewer SE's (GI distress, postural hypotension, and dyskinesias)
relapsing/remitting MS
This is one type of MS. Symptoms due to an acute attack may last from several weeks to months and then spontaneously improve. Several medications help control symptoms by limiting the immune attack and reducing associated inflammation. Steroids, which have been used to treat this type of MS for more than three decades, may be effective in shortening attacks, thus helping to speed recovery from MS-related acute attacks.
progressive MS
This is one type of MS. There is ongoing nerve fiber degeneration, symptoms become permanent and gradually worsen. This form of MS leads to a progressive accumulation of disability usually affecting mobility, strength, balance, and coordination.
stage 4
This is sometimes referred to as delta sleep because of the delta waves that occur during this time. It is a deep sleep that lasts for about 30 minutes. Sleepwalking and bed-wetting typically happen at the end. Brain waves are the slowest and largest.
receptive field
This is the area of skin over which each individual receptor responds.
bell-shaped curve
This is the classical curve relating stress to brain function - a little bit is good for you, a bit more is better, but too much is bad!
HPA axis
This links together the hypothalamus, pituitary gland, adrenal cortex and hippocampus by a bloodstream highway carrying specialised hormones.
radiation
This method is used to stop a tumor's growth or cause it to shrink.
chemotherapy
This method of treating brain tumors destroys tumor cells that may remain after surgery and radiation, but it is not very effective for gliomas, largely because it is hard for these drugs to reach the brain.
cAMP-response element binding protein (CREB)
This molecule is activated after the release of calcium ions and cAMP and is released itself in the nucleus of the neuron to activate genes which may direct protein synthesis
nerve growth factor (NGF)
This neurotrophin slows the destruction of neurons that use acetylcholine. Important for sensory neuron survival. When infused into the brains of rats, it prevented cell death and stimulated the regeneration and sprouting of damaged neurons that are known to die in Alzheimer's disease. When aged animals with learning and memory impairments were treated with it, scientists found that these animals were able to remember a maze task as well as healthy aged rats. It also holds promise for slowing the memory deficits associated with normal aging.
stroke
This occurs when a blood vessel bringing oxygen and nutrients to the brain bursts or is clogged by a blood clot or some other particle. As a result, the brain is deprived of blood, causing the death of neurons within minutes. Depending on its location, it can cause many permanent disorders, such as paralysis on one side of the body and loss of speech. Can be caused by an overproduction of cytokines.
inhibitory post-synaptic potential (ipsp)
This occurs when the activation of receptors leads to the opening of ion channels that allow the inflow of negatively charged ions giving rise to a change in membrane potential. This opposes membrane depolarisation and therefore the initiation of an action potential at the cell body of the receiving neuron. It is a shift in membrane potential from 0 mV to a value closer to -70 mV.
mesolimbic pathway
This pathway originates in the ventral tegmental area and innervates several structures of the limbic system, including the nucleus accumbens. This dopaminergic pathway is important for memory and for motivating behaviours. By blocking this pathway, antipsychotic drugs reduce the intense emotions caused by conditions such as schizophrenia.
Apolipoprotein E (apoE)
This protein influences susceptibility for Alzheimer's later in life, exists in three forms.
crossed extension reflex
This reflex balances the body by extending the leg not receiving the flexion withdrawal reflex.
stage 1
This stage of sleep is associated with theta waves and the disappearance of alpha waves. EEG slows down even more, heart rate and blood pressure drops; Very easily able to wake up; myoclonic jerk can occur.
22q deletion syndrome
This syndrome causes a certain section of chromosome 22 to be deleted and may put people at a higher risk of developing mental illness.
endogenous opioid system
This system regulates the body's natural painkillers.
functional magnetic resonance imaging (fMRI)
This technique compares brain activity under resting and active conditions. It combines the high-spatial resolution, noninvasive imaging of brain anatomy offered by standard MRI with a strategy for detecting increases in blood oxygen levels when brain activity brings fresh blood to a particular area of the brain — a correlate of neuronal activity. This technique allows for more detailed maps of brain areas underlying human mental activities in health and disease. To date, it has been applied to the study of various functions of the brain, ranging from primary sensory responses to cognitive activities. Given its temporal and spatial resolution, as well as its noninvasive nature, this technique is often preferred for studies investigating dynamic cognitive and behavioral changes.
FOXP2
This transcription has a gene that shows rapid change in the human lineage. Several lines suggest that the gene for this transcription factor functions in vocalization in vertebrates. rare mutations of this gene impede learning to make sequences of mouth and jaw movements that are involved in speech, accompanied by difficulties that affect both spoken and written language.
partial epilepsy
This type of epilepsy is characterized by seizures in which the individual maintains consciousness or has altered awareness and behavioral changes. They can produce localized visual, auditory, and skin sensory disturbances; repetitive uncontrolled movements; or confused, automatic behaviors. Such seizures arise from excessive electrical activity in one area of the brain, such as a restricted cortical or hippocampal area. Unfortunately, these are generally more difficult to treat. Often, they can be controlled with a single antiepileptic that prevents seizures or lessens their frequency, but sometimes a combination of these drugs is necessary.
slow wave sleep
This type of sleep comprises four stages during which brain waves slow down, accompanied by relaxation of the muscles and the eyes. Heart rate, blood pressure, and body temperature all fall. If awakened during this time, most people recall only fragmented thoughts, not active dreams.
15
Those who develop MS before what age are affected by environmental factors?
dendritic spines
Tiny protuberances that stick out from the dendrites. These are where incoming axons make most of their connections. Proteins transported to these are important for creating and maintaining neuronal connectivity.
analogue coding
To reduce power and increase speed, this type of coding codes in continuous changes in voltages, as do neurons in their sub-threshold state.
ventral pathway
Travels from the primary visual cortex to the temporal lobe towards the base of the brain and is involved in object recognition ("what").
psychotherapy
Treatment involving psychological techniques; consists of interactions between a trained therapist and someone seeking to overcome psychological difficulties or achieve personal growth.
cognitive behavioral therapy
Treatment involving the combination of behaviorism (based on the theories of learning) and cognitive therapy (based on the theory that our cognitions or thoughts control a large portion of our behaviors). Used to treat panic disorders, phobias, and PTSD.
neurofibrillary tangles
Twisted protein fibers that form within certain brain cells as people age. People with Alzheimer's disease have an excessive number of such tangles.
Schwann cells
Type of glia in the PNS, supporting cells of the peripheral nervous system responsible for the formation of myelin.
oligodendrocyte
Type of glial cell in the CNS that wrap axons in a myelin sheath. These cells surround axons and allow them to conduct their signals efficiently by myelinating them.
petit mal epilepsy
Type of seizure disorder often seen in children. Characterized by periods of inattention, which are not subsequently remembered. Also called spells of absence. Stargazer mice are important in research for this.
Parkinson's disease
Typically, people start showing symptoms over the age of 50. In fact, aging is the only known risk factor for the development of this disorder. This disease is characterized by slowness of movement, muscular rigidity, and walking and balance impairment. Many affected individuals may develop a resting tremor as well. Besides impairment in motor movement, it may also cause changes in non-motor brain function. Caused by the loss of norepinephrine neurons in the substantia nigra.
neural stem cells
Uncommited cells which mature into ones needed by the brain. Provide novel insights into tumor genetics and perhaps better treatment.
molecular neurobiology
Uses the genetic material of neurons to understand the structure and function of brain molecules
suprachiasmatic nucleus
Visual inputs to this small group of nerve cells in the hypothalamus synchronize our internal circadian rhythms to match with natural light and dark. It also receives input directly from the retina, and the clock can be reset by light so that it remains linked to the outside world's day-night cycle.
cytokines
What activates the production of acute phase proteins in the liver?
Na+
What are the first channels to open during an action potential?
dyslexic
What are these artists/scientists: Leonardo da Vinci, Hans Christian Andersen, Edison and Einstein?
basal ganglia and cerebellum
What areas are important for skill learning?
steroids
What drugs can help curb MS?
2/3
What fraction of a neuron's energy is used to fuel sodium/potassium ATPase
adrenal glands
What glands does nicotine stimulate?
K+
What ions does the switch of voltage in a neuron generate to flow out?
amygdala
What is important for emotional learning?
liver
What is the key site for production of acute phase proteins?
Tobacco use
What is the leading preventable cause of death in the US?
Fetal alcohol syndrome
What is the leading preventable cause of mental retardation, and affects 1-3 of every 1,000?
motor neurons
What is the the final common path to the muscles that move your bones?
cell division
What is the very first step in brain development?
-70 mV
What is the voltage inside a neuron before the action potential?
30 mV
What is the voltage of a neuron after it switches?
1.5 L
What is the volume of the brain?
serotonin
What neurotransmitter does both ecstasy and d-LSD affects that causes the mid-week blues?
norepinephrine
What neurotransmitter remains very high in people with PTSD?
dopamine
What neurotransmitter's release does Dexedrine and Speed mostly affect?
Caucasians
What race is more susceptible than other races to getting MS?
linkage and daylight
What things stop the production of per and tim and help manage the circadian rhythm in Drosophila?
dopamine, serotonin
What two neurotransmitters do amphetamines affect?
perirhinal cortex and hippocampus
What two structures are very important for episodic memory?
population code
What, instead of individual neurons, controls the actions that are specified by the firing of an ensemble of neurons ?
electrical repulsion
When NMDA receptors are activated quickly, this phenomenon causes a large depolarisation in the postsynaptic neuron and this dispels the Mg2+ from the NMDA ion channels .
calcium channels
When an action potential arrives at the nerve terminal, these channels open, and ACh is released into the synapse, where it attaches to ACh receptors on the target cells.
metabotropic receptors
When habits and actions are involved, the neurotransmitter dopamine is released on to neurons in the basal ganglia where it acts at what receptors?
working memory
When we have new experiences, information initially enters this, a transient form of declarative memory. It depends on the prefrontal cortex as well as other cortical areas. A newer understanding of short-term memory that focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long-term memory.
excitatory post-synaptic potential (epsp)
When you bind an excitatory neurotransmitter to a receptor that can move that neuron closer to its threshold for having an action potential. If the ion channel allows positive ions (Na+ or Ca++) to enter, the inflow of positive current leads to excitation. This produces a swing in the membrane potential. It is a shift in membrane potential from -70 mV to a value closer to 0 mV.
left frontal and parietal lobes
Where are the auditory parts of working memory lateralized?
dorsal roots
Where do touch receptors send their impulses along?
Frontal and parietal lobes
Where is working memory largely located in?
Pacinian corpuscles
Which has larger receptive fields? Pacinian corpuscles or Meissner's corpuscles.
right
Which hemisphere is the visual sketchpad?
serotonin and norepinephrine
Which neuromodulatory neurotransmitters do antidepressants enhance the effects of?
AMPA, NMDA and kainate
Which of the four glutamate receptors are ionotropic?
mGluR
Which of the four glutamate receptors are metabotropic?
Medical Research Council and the Wellcome Trust
Which organizations have put mental health high on their agenda for research over the next decades?
E.M.I
Who payed for the first brain scanners by buying the Beatles records?
fragile X syndrome
X-linked defect affecting the methylation and expression of the FMR1 gene. Associated with chromosomal breakage. The 2nd most common cause of genetic mental retardation (after Down syndrome). Trinucleotide repeat disorder (CGG)
clonazepam
a benzodiazepine used to treat Parkinson's, as well as Parkinson's related disorders, such as periodic limb movements and REM behavior disorder.
valium
a benzodiazepine which increases the activity of GABA.
electroconvulsive therapy
a biomedical therapy for severely depressed patients in which a brief electric current is sent through the brain of an anesthetized patient.
human immunodeficiency virus (HIV)
a bloodborne infection and STD in which the virus damages or kills the cells of the immune system, causing it to progressively fail.
traumatic brain injury
a blow to the head or a penetrating head injury that damages the brain. Most commonly occurs due to falls or motor-vehicle related events.
corpus callosum
a bundle of fibers bridging the two hemispheres that allow for communication between them.
complement proteins
a cascade of proteins important in killing invader cells
chromosome 16
a chromosome that, when some sections are deleted, can lead to a variety of neurological symptoms, including autism in some individuals.
prostaglandins
a class of compounds made from lipids by an enzyme called cyclooxygenase. These very small and short-lived molecules have powerful effects, including the induction of a fever and the generation of pain in response to inflammation. An unsaturated fatty acid that performs a similar function to that of hormones in controlling smooth muscle contraction, blood pressure, inflammation, and body temperature.
striatum
a collective term for the caudate nucleus and putamen, involved in the initiation of will movement, plays a role in procedural memory. Part of the limbic system.
blindsight
a condition in which a person can respond to a visual stimulus without consciously experiencing it
allodynia
a condition in which innocuous stimuli induce pain
deep dyslexia
a condition in which reading unfamiliar words and non-words is impaired and there are semantic errors (e.g., reading missile as rocket)
mitochondrial toxicity
a condition in which the mitochondria of a body's cells become damaged or decline significantly in number; it occurs as a side effect of certain antiretroviral drugs used to treat human immunodeficiency virus, or HIV.
amblyopia
a condition in which the vision of one eye is greatly reduced because the eyes do not work well together.
Down syndrome
a condition of intellectual disability and associated physical disorders caused by an extra copy of chromosome 21. Some of the characteristics: mild to moderate intellectual disabilities; low muscle tone; an upward slant to the eyes; a flat facial profile; an enlarged tongue; and an increased risk of congenital heart defects, respiratory problems, and digestive tract obstruction.
medial temporal lobes
a cortical area of the brain in the temporal lobes associated with learning and long-term memory storage. Damage can cause anterograde amnesia.
variant Creutzfeldt-Jakob disease (vCJD)
a disease caused by eating beef from a cow that was contaminated with bovine spongiform encephalitis.
autoimmune disease
a disease in which the immune system attacks the organism's own cells
strabismus
a disorder in which the eyes point in different directions or are not aligned correctly because the eye muscles are unable to focus together
bovine spongiform encephalitis (mad cow disease)
a disorder of the nervous system in which there is a modified protein called the prion protein that causes a lot of damage in the brain and spinal cord.
tuberoinfundibular pathway
a dopaminergic pathway that connects the hypothalamus to the pituitary gland, where it influences the secretion of hormones such as prolactin.
stressor
a factor inducing stress
prion diseases
a family of rare progressive neurodegenerative disorders that affect both humans and animals due to contamination.
beta amyloid
a fibrillar peptide that is produced in abnormally high levels in persons with Alzheimer's disease.
APOE epsilon 4
a form of apoE associated with enhanced risk of AD.
semantic memory
a form of declarative knowledge that includes general facts and data.
MECP2
a gene associated with Rett syndrome.
tim
a gene in multiple species but is most notable for its role in Drosophila for encoding its corresponding protein, an essential protein that regulates circadian rhythm. Its mRNA and protein oscillate rhythmically with time as part of a transcription-translation negative feedback loop involving the period (per) gene and its protein.
per
a gene located on the X chromosome of Drosophila melanogaster. Oscillations in levels of both the gene transcript and its corresponding protein have a period of approximately 24 hours and together play a central role in the molecular mechanism of the Drosophila biological clock driving circadian rhythms in eclosion and locomotor activity
MLL2
a gene responsible for Kabuki syndrome.
RBI
a gene that, when altered, causes inherited retinoblastoma.
FMR1
a gene which is abnormal in people diagnosed with fragile X syndrome.
ventrolateral preoptic (VLPO) nucleus
a group of GABA and galanin releasing inhibitory neurons in the preoptic area whose activity suppresses alertness and behavioral arousal and promotes sleep. Destruction of these neurons causes irreversible insomnia.
atherosclerosis
a hardening of the arteries; can happen due to an overexposure to glucocorticoids as is the case in chronic stress.
Lidocaine
a local anesthetic more popular to use by dentists today. For some neuropathic pain conditions in which a light touch to the skin can produce severe pain, a topical treatment of this may be effective.
Novocain
a local anesthetic used by dentists that is not as popular to use as Lidocaine is.
methadone
a long-acting oral opioid that helps keep craving, withdrawal, and relapse under control. It helps opiate addicts rehabilitate themselves by preventing withdrawal symptoms that can motivate continued drug use.
heroin
a man-made chemical derivative of the plant product morphine. It hijacks a system in the brain that employs naturally occurring neurotransmitters known as endorphins. These are important in pain control - and so drugs that copy their actions are very valuable in medicine. It is injected or smoked whereupon it causes an immediate pleasurable sensation - possibly due to an effect of endorphins on reward mechanisms. It is highly addictive, but, as dependence develops, these pleasurable sensations quickly subside to be replaced by an incessant "craving". It is a very dangerous drug that can kill in even modest overdose (it suppresses breathing reflexes).
naltrexone
a medication developed for heroin and alcohol addiction. Works by blocking opioid receptors.
Jeffery Watkins
a medicinal chemist who transformed the study of excitatory transmission in the brain by developing drugs like AP5 that act on specific glutamate receptors.
Genome-wide association studies (GWAS)
a method that adopts techniques from the epidemiological method, whereby "researchers compare the genomes of 'cases' and 'controls'—or diseased and healthy people.
hypomania
a mild form of mania found in patients with bipolar disorder.
patch-clamping
a modern electrical recording technique in which neuroscientists are able to study the movement of ions through individual ion-channels in all sorts of neurons, and so make very accurate measurements of these currents in brains much more like our own.
migraine
a more common cause of headache. As well as a sore head (often on one side), people feel sick, find bright lights or loud noises discomforting, and experience a migrainous aura consisting of flashing lights or jagged lines. The aura generally precedes the headache.
antagonist
a muscle that moves a joint in a direction that opposes its intended direction of movement.
agonist
a muscle that moves a joint in an intended direction.
Korsakoff's syndrome
a neurodegenerative disease involving severe memory disorders associated with damage to brain structures and areas involved with memory (associated with chronic alcoholism)
motor neuron
a neuron that sends an impulse to a muscle or gland, causing the muscle or gland to react
tetrodotoxin (TTX)
a neurotoxin coming from the pufferfish that blocks voltage gated Na+ Channels, halting electrical signals among neurons. When given discrete, targeted doses, it can be used specifically to shut down those nerve cells involved in sending constant signals of chronic pain.
MPTP (1-methyl-4-phenyl-1, 2, 3, 6 tetrahydropyridine)
a neurotoxin that was first discovered in the late 1970s, when it was accidentally synthesized by designers of illicit drugs looking for ways to produce a heroin-like compound. The drug addicts who self-injected this toxin developed a neurological condition that was indistinguishable from Parkinson's. Researchers soon found that the toxin is converted in the brain to a substance that destroys dopamine neurons. This finding led to using the toxin as a tool for medical studies.
galanin
a neurotransmitter that stimulates a desire for fats
aspirin
a nonopioid that prevents the production of prostaglandins.
adrenal glands
a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress.
varenicline
a prescription drug used for smoking cessation. This medication interacts directly with the acetylcholine-nicotinic receptor in a key part of the brain's reward circuitry and prevents nicotine from activating this circuit.
hyperventilation
a procedure used to temporarily decrease blood volume in patients with increased intracranial pressure.
migration
a process marked by new neurons beginning their journey to the proper position in the brain. Guidance molecules are important for this process.
word deafness
a profound inability to comprehend auditory speech on any level: cannot recognize words even though the ability to hear pure tones remains in tact.
dementia
a progressive and severe impairment in mental function that interferes with the activities of daily living.
ephrin
a protein secreted by neurons in many parts of the developing nervous system that helps establish topographic axonal connections by causing contact repulsion.
Nogo-A
a protein that inhibits nerve regeneration.
RPE65 protein
a protein that, when mutated, can cause an inherited form of blindness.
early-onset Alzheimer's disease
a rare, dominantly inherited form of AD that begins earlier in life.
retinoblastoma
a rare, highly malignant, childhood eye tumor that can lead to blindness and death.
magnetoencephalography (MEG)
a recently developed technique that reveals the source of weak magnetic fields emitted by neurons. An array of cylinder-shaped sensors monitors the magnetic field pattern near the patient's head to determine the position and strength of activity in various regions of the brain. In contrast with other imaging techniques, it can characterize rapidly changing patterns of neural activity — down to millisecond resolution — and can provide a quantitative measure of the strength of this activity in individual subjects. Moreover, by presenting stimuli at various rates, scientists can determine how long neural activation is sustained in the diverse brain areas that typically respond.
nucleus accumbens
a region of the forebrain that receives dopaminergic innervation from the ventral tegmental area; DA release in this structure represents a common final event associated with the reinforcing effects of opiates, cocaine, amphetamines, nicotine, PCP, and alcohol.
reflex
a relatively fixed, automatic muscle response
nerve ring
a ring of nerves in worms where netrin has been studied
chlorotoxin
a scorpion-derived toxin that interferes with the spread of a brain tumor and has shown promise in clinical studies. This therapy has extended life expectancy significantly.
AIDS dementia
a severe case of HAND. Dementia is common in later stages of AIDs because advanced AIDs gets into brain tissue. Virus invades brain tissue and may be exacerbated by other infections and tumors. Gradual loss of memory and cognitive ability, and impaired motor function are typical.
incus
a small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus and stapes.
statistical parametric mapping (SPM)
a statistical technique created by Karl Friston for examining differences in brain activity recorded during functional neuroimaging experiments using neuroimaging technologies such as fMRI or PET. Has standardized the processing of imaging data. These maps are often given colours, with a fiery yellow used for the 'hottest' areas of activity through to blue and black for 'cooler' areas. One widely-used analysis package that has standardized the processing of imaging data.
methylprednisolone
a steroid that is the only FDA-approved treatment for spinal cord injury.
levodopa
a substance from which dopamine is synthesized (an effective treatment for Parkinson's')
mania
a symptom of bipolar disorder, characterized by an increased energy, decreased need for sleep, a marked interest in goal-directed activities, and poor judgment. For example, during episodes, individuals may spend excessively or engage in uncharacteristic drug abuse or sexual behaviors. Individuals may be euphoric, but some are predominantly irritable. Typically, individuals are grandiose, and when it is particularly severe, they may have delusions or hallucinations. In such instances, patients may believe that they are prophets, deities, or on a special mission.
MDMA (ecstasy)
a synthetic psychoactive drug with hallucinogenic and amphetamine-like properties. Users encounter problems similar to those found with the use of amphetamines and cocaine. Recent research also links chronic use of this drug to long-term changes in those parts of the brain critical for thought, memory, and pleasure.
event-related fMRI
a technique in magnetic resonance imaging that can be used to detect changes in the BOLD (Blood Oxygen Level Dependent) hemodynamic response to neural activity in response to certain events. Even very brief thoughts or brain events (as little as one or two seconds in duration) can be measured in this type of neuroimaging. One method is a block related design, in which two or more different conditions are alternated in order to determine the differences between the two conditions, or a control may be included in the presentation occurring between the two conditions. By contrast, event related designs are not presented in a set sequence; the presentation is randomized and the time in between stimuli can vary. It attempts to model the change in fMRI signal in response to neural events associated with behavioral trials.
microdialysis
a technique used to measure the amount of a particular brain chemical found in a specified area of the brain. Following the discovery that chemicals and other molecules are transported within neurons, methods have been developed to visualize brain activity and precisely track nerve fiber connections within an animal's nervous system. This can be done by injecting a radioactive amino acid into brain cells, allowing activities in the nervous system to show up on film. In another technique, the enzyme horseradish peroxidase is injected and taken up by nerve fibers that later can be identified under a microscope.
Richard Feynman
a theoretical physicist, who described his reason for doing science as being for "the pleasure of finding out". Ironic - because he threw himself headlong into working out why one of the American Space Shuttles, Challenger, exploded soon after take-off.
idiopathic epilepsy
a type of epilepsy that arose from an uncertain cause. Most of these epilepsies probably are due to the inheritance of one or more mutant genes, often a mutant ion channel gene.
symptomatic epilepsy
a type of epilepsy that has a known or presumed cause. They result from a wide variety of brain diseases or injuries, including birth trauma, head injury, neurodegenerative disease, brain infection, brain tumor, or stroke.
benzodiazepine
a type of medication used to treat panic disorder, as a hypnotic, anticonvulsant (diazepam, lorazepam), preanesthetic or procedural sedation (midazolam, lorazepam)
peripheral neuropathy
a type of nerve injury in extremities that causes discomfort ranging from tingling and burning to severe pain; it is also a major neurological problem commonly seen in HIV patients. Can become more severe in HIV patients as mitochondrial toxicity increases in severity.
single photon emission computed tomography (SPECT)
a type of nuclear imaging test that produces 3D computer-reconstructed images showing perfusion through tissues and organs (not as detailed as PET because the tracers it uses break down at a slower rate and do not require a nearby particle accelerator)
neuropathy
a type of pain usually felt as burning or tingling and resulting from direct stimulation of nerve tissue of the peripheral or central nervous system; comes from injury to the nervous system.
experience-expectant plasticity
a type of plasticity that refers to the integration of environmental stimuli into the normal patterns of development. Certain environmental exposures during limited critical, or sensitive, periods of development are essential for healthy maturation. For example, finches need to hear adult songs before sexual maturation in order for them to learn to sing at a species-appropriate level of intricacy.
nervous system
a vast biological computing device formed by a network of gray matter regions interconnected by white matter tracts.
Jacqueline du Pré
a well known musician who suffered from multiple sclerosis
Nikos Logothetis
a young researcher making a major contribution to understanding the relationship between the activity of neurons in the brain and the signals seen in brain-imaging experiments.
intermediate zone
a zone where neurons gradually accumulate after dividing
binocularity
ability to merge visual images from both eyes, which provides depth perception and a three-dimensional view of the world. The cells in the visual areas at the back of the brain can fire in response to an image in either eye.
delusions
abnormal beliefs - commonly bizarre ideas which are often persecutory in nature
neuritic plaques
accumulation of beta amyloid tissues in Alzheimer's patients.
REM-generating neurotransmitters
acetylcholine, glutamate
acquired immunodeficiency syndrome (AIDS)
advanced HIV infection; a group of clinical signs and symptoms associated with suppression of the immune system and marked by opportunistic infections, secondary neoplasms, and neurologic problems. Examination of the brains of persons dying with this syndrome can reveal loss of neurons, abnormalities in the white matter, and injury to cellular structures that are involved in signaling between neurons. There also may be inflammation and vessel disease.
refractory period
after firing when a neuron will not fire again no matter how strong the incoming message may be
globus pallidus
along with putamen, caudate nucleus and substantia nigra, makes up the basal ganglia. The internal division of this structure provides inhibitory input to the motor cortex via the thalamus; sometimes stereotaxically lesioned to treat symptoms of Parkinson's
prazosin
alpha-1 blocker drug used to lower blood pressure for more than 20 years, is now used to treat nightmares experienced with PTSD.
orthography
alphabetic visual symbols in their right order
motor unit
an alpha motor neuron and all the muscle fibers it contains form this functional unit.
gamma-aminobutyric acid (GABA)
an amino acid transmitter in the brain whose primary function is to inhibit the firing of nerve cells. Known for decreasing anxiety.
monkey
an animal used widely in vision studies, especially with amblyopia.
valproate
an anticonvulsant used to treat patients with bipolar disorder.
ß-interferon
an antinflammatory cytokine in the interferon family used to treat multiple sclerosis (MS).
multiple sclerosis (MS)
an autoimmune disease in which the body's natural defenses attack the myelin sheath covering the axons of neurons in the CNS. The loss of myelin results in damage to the nerve fibers. In some instances, the damage may be so severe that the nerve fiber deteriorates. Following loss of myelin, the axon's sheath is either repaired or replaced by scars, or scleroses. Scarring is usually associated with further degeneration of the nerve fibers. Lesions or plaques appear in multiple places within the CNS. Siblings of people with this are at a 2 to 3 percent risk of developing this, whereas the risk for an identical twin of someone with this is 30%. The disease is as much as five times more prevalent in temperate zones than it is in the tropics. Caucasians are more susceptible than other races. The symptoms depend on the site of the damage. Because the spinal cord, cerebellum, and optic nerve are commonly affected, symptoms such as numbness, clumsiness, and blurred vision often occur. However it can affect many other brain areas, including white matter and gray matter, so symptoms may also include slurred speech, weakness, loss of coordination, pain, uncontrollable tremors, loss of bladder control, memory loss and other cognitive problems, depression, and fatigue. An increasing range of newer, more selective drugs are now becoming available or are in clinical trials. While many medications and therapies are available to control symptoms such as spasticity, pain, fatigue, and mood swings, as well as bladder, bowel, or sexual dysfunction, no treatments are available for the nerve degeneration that causes the progression of the disease. Can be caused by overproduction of cytokines. a disease of young adults. It is characterised by repeated episodes of weakness, numbness, double vision or poor balance, that last for a few weeks before recovery - apparently back to normal. The cycle between periods of illness and remission is a feature of the disease.
lithium
an element known for its mood-stabilizing effect. Was injected into guinea pigs, which were found to be placid. Researchers then used the element to help alleviate manic symptoms of patients with bipolar disorder.
muscle fiber
an elongated contractile cell that forms the muscles of the body.
phrenology
an ill-fated theory that claimed bumps on the skull could reveal our mental abilities and our character traits.
long-term potentiation (LTP)
an increase in a synapse's firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.
phobia
an intense, irrational fear of a particular object or situation. Individuals can develop this disorder of almost anything, including dogs, dating, blood, snakes, spiders, or driving over bridges. Exposure to the feared object or situation can trigger an extreme fear reaction that may include a pounding heart, shortness of breath, and sweating. Cognitive behavioral therapy is an effective treatment.
Aplysia californica
an invertebrate sea slug frequently used as a subject of experiments on learning and memory
withdrawal reflex
an involuntary process that causes a part of the body to automatically pull away from something that is causing pain
tardive dyskinesia
an irreversible movement disorder, which results in aimless, uncontrollable movements, such as grimacing or rapid eye blinking and other involuntary movements of the facial muscles, tongue, and limbs; a possible neurotoxic side effect of long-term use of antipsychotic drugs that target D2 dopamine receptors.
naloxone
an opioid antagonist similar to naltrexone.
alcohol addiction
an unhealthy addiction to alcohol; causes many liver and brain complications.
amitriptyline and duloxetine
antidepressants
gabapentin and topiramate
antiepileptics
stress
any external stimulus that threatens homeostasis
cerebrovascular disease
any functional abnormality of the cerebrum caused by disorders that affect the blood vessels supplying the brain, which may result in a stroke
sensory neurons
are coupled to receptors specialised to detect and respond to different attributes of the internal and external environment.
intrafusal muscle fibers
are part of the sensory system conveying information back to the brain and spinal cord about muscle stretch and are innervated by gamma motoneurons located in the spinal cord and brain stem
medial temporal region
area of the brain that is important for forming, organizing, consolidating, and retrieving memory
locus coeruleus
area of the brainstem that contains norepinephrine, a neurotransmitter that triggers the body's fight-or-flight response; has been implicated in panic disorder
lesions (plaques)
areas of disease activity found in patients with neurodegenerative disorders or other brain disorders.
olfactory bulbs
areas of the brain located just above the sinus cavity and just below the frontal lobes that receive information from the olfactory receptor cells
sporadic ALS
arising in individuals with no known family history of the disorder. Potential causes or contributors to the disease include an excess amount of the neurotransmitter glutamate, which becomes toxic; oxygen in a dangerous form in the body, resulting in what is called oxidative distress; environmental factors; and an autoimmune response in which the body's defenses turn against body tissue.
silicon retina
artificial version of a biological network has been built consisting of this that captures light and adapts its output automatically to changes in overall lighting conditions. It connects to two silicon neurons that, like real neurons in the visual cortex, have the job of extracting information about the angles of lines and contrast boundaries in the retinal image.
nonopioids
aspirin and related NSAIDs used as analgesics.
processes
axons and dendrites
propranolol
beta-blocker drug being tested in individuals exposed to trauma, but these agents must be administered shortly after PTSD trauma.
macular degeneration
breakdown or thinning of the tissues in the macula, resulting in partial or complete loss of central vision
contusions
bruises found on the brain after a head injury.
cytoskeleton
built up of rods of tubular and filamentous proteins that extend out into dendrites and axons alike. The structure is a bit like a canvas stretched over the tubular skeleton of a frame tent.
white matter
bundles of myelinated nerve fibers; tissue that serves to connect different brain regions.
Broca's aphasia
caused by damage to the left frontal lobe: a syndrome in which speech production abilities are impaired. Speech output is slow and halting, requires effort, and often lacks complexity in word or sentence structure. Although speaking is impaired, nonfluent aphasics still comprehend heard speech, although structurally complex sentences may be poorly understood.
Wernicke's aphasia
caused by damage to the left temporal lobe: comprehension of heard speech is impaired. Speech output, although of normal fluency and speed, is often riddled with errors in sound and word selection and tends to be unintelligible gibberish.
free radicals
cell byproducts that destroy fats and proteins vital to normal cell function.
sensory cells
cells stimulated by sugars, salts, and acids and are located on taste buds. Also found on the mucus lining of the nose.
astrocytes
cells that nourish and protect neurons.
neuroglia
cells that transport nutrients to neurons, clean up brain debris, digest parts of dead neurons, and help hold neurons in place
neurovascular link
cerebral circulation. By virtue of this, there is a local increase in cerebral blood flow in active areas.
dyslexia
characterized by an unexpected difficulty in speaking and reading in children and adults who otherwise possess the intelligence, motivation, and schooling considered necessary for accurate and fluent reading. Studies indicate that although there can be improvement, it is a persistent, chronic condition. There is now a strong consensus that the central difficulty in most forms of this condition reflect a deficit within the language system — more specifically, in phonology.
autism spectrum disorders (ASD)
characterized by impaired social skills; verbal and nonverbal communication difficulties; and narrow, obsessive interests or repetitive behaviors. Common associated symptoms include intellectual disabilities, seizures, and gastrointestinal problems.
post-traumatic stress disorder (PTSD)
characterized by intense fear, helplessness or horror, intrusive recollections of the traumatic event, avoidance and numbing, and hyperarousal. In addition, the disorder is associated with dysregulation of stress hormones, disordered sleep, and major depressive disorder. Military personnel are at elevated risk for exposure to trauma, so not surprisingly, they have higher prevalence rates compared to the general population. Scientists have studied this disorder in depth and have learned that the very high levels of norepinephrine released in the brain during stress remain at heightened levels.
rapid eye movement (REM) sleep
characterized by neocortical EEG waves similar to those observed during waking. Accompanied by atonia. Only the muscles that allow breathing and control eye movements remain active. Active dreaming takes place. Heart rate, blood pressure, and body temperature become much more variable. Men often have erections during this stage. The first period usually lasts 10 to 15 minutes.
neuromodulators
chemicals released in the nervous system that influence the sensitivity of the receiving neuron to neurotransmitters
analogs
chemicals with molecular structures similar to neurotransmitters
psychostimulants
cocaine and morphine; elevate dopamine levels in nucleus accumbens
visual sketchpad
component of working memory responsible for handling visual and spatial info, how things look and allow us to manipulate image in our mind; ex. rotate a shape to see how it might appear at different angle
neuroethics
considerations of the ethical, legal and social implications of neuroscience findings.
migrainous aura
consists of flashing lights or jagged lines. Brain imaging reveals increased activity in these regions at the start of a migraine. In response, there is a brief increase in local blood supply (which brings on symptoms like flashing lights), immediately followed by reduced blood flow (reflected in temporary weakness).
midbrain
consists of two pairs of small hills called colliculi and has clusters of neurons that regulate activity in widespread parts of the central nervous system and are thought to be important for reward mechanisms and mood.. Can depress signals of pain.
superior temporal gyrus
contains the primary auditory cortex, which is responsible for processing sounds. Includes the Wernicke's area, which (in most people) is located in the left hemisphere. It is the major area involved in the comprehension of language.
cerebellum
contains two hemispheres and helps control movement and cognitive processes that require precise timing. Deemed "little brain". A large structure of the hindbrain that controls fine motor skills. It receives direct information from all the sensory receptors in the head and the limbs and from most areas of the cerebral cortex. It apparently acts to integrate all this information to ensure smooth coordination of muscle action, enabling us to perform skilled movements more or less automatically.
medulla oblongata
controls respiration, heart rhythms, and blood glucose levels
central executive system
controls the flow of information, supported by two additional memory stores. Controls the deployment of attention and divide attention as needed
posterior parietal cortex (PPC)
controls the flow of information.
opiates
create effects like those elicited by the naturally occurring opioid peptides. They relieve pain, depress breathing, cause nausea and vomiting, and stop diarrhea — important medical uses. But in large doses, heroin can make breathing shallow or stop it altogether — the cause of death in thousands of people who have died of heroin overdose.
diabetic neuropathy
damage to nerves in the body resulting from high blood sugar levels.
myasthenia gravis
decrease in receptor sites for acetylcholine. weakness observed in muscles, eyes mastication and pharyngeal musles. watch for aspiration. immune system attacks the junctions where nerves connect with muscles.
cerebellar ataxia
degeneration of purkinje neurons in the cerebellum causes a movement disorder known as ___
HIV-associated neurocognitive disorder (HAND)
depression-like and progresses to social withdrawal, apathy, motor, and cognitive problems; can be direct effects of HIV or indirect from other viruses. Individuals with this disorder have mental problems ranging from mild difficulty with concentration, memory, complex decision-making or coordination to progressive, fatal dementia.
neuromorphic engineering
describes the translation of neurobiology into technology.
demyelination
destruction or removal of the myelin sheath that covers a nerve or nerve fiber
parvocellular cells
detect shape, high color spatial resolution (see very fine detail), low temporal resolution (only work with slow moving/still objects)
Alan Baddeley
developed the idea of working memory, which consists of a number of different interacting systems
subparaventricular nucleus
directly adjacent brain area to the suprachiasmatic nucleus and receives input from this later brain structure. It in turn signals the dorsomedial nucleus of the hypothalamus.
hallucinations
disorders of perception where sufferers experience abnormal sensory impressions, such as hearing voices when there is no one there
odorants
dissolved chemicals that stimulate olfactory receptors
extrafusal muscle fibers
do the work of moving bones/tissue and are innervated by alpha motoneurons located in the spinal cord and brain stem
monoamines
dopamine, epinephrine, norepinephrine, serotonin, and tyramine belong to this class of compounds. A reduction of these is found in Alzheimer's patients.
serotonin (5-HT) receptors
drugs aimed at these receptors is important for curing migraines.
second-generation antipsychotics
drugs developed to be more effective in treating the positive symptoms of schizophrenia. They do not have the same likelihood of causing Parkinsonian effects but can lead to other debilitating side effects, such as very large weight gain, blood disorders, and muscle pain and dysfunction.
first-generation antipsychotics
drugs that act by inhibiting certain dopamine receptors. This mechanism accounts for the high prevalence of side effects, like those seen in Parkinson's and schizophrenia, that are associated with the use of these drugs.
anticoagulant drugs
drugs that can reduce the likelihood of clots forming, traveling to the brain, and causing a stroke.
anencephaly
during development, failure of closure at the head end can result in the complete absence of an organised brain.
endogenous analgesics
enkephalins, endorphins & dynorphins: Under conditions of likely injury, such as soldiers in battle, pain sensation is suppressed to a surprising degree- presumably because these substances are released.
"next generation" sequencing
entire genomes and exomes sequenced using multiple parallel reactions to analyze short segments of DNA and compare the results to known sequences.
genome
entire set of genetic information that an organism carries in its DNA.
cyclo-oxygenase (COX) enzymes
enzymes that make the inflammatory and pain-producing chemical prostaglandin. NSAIDs work by inhibiting these.
neurophysiology
explore the relationships between brain/nervous systems and behavior
spinal cord
extension of the brain through the vertebral column. Receives sensory information from all parts of the body below the head. Uses this information for reflex responses to pain, for example, and it also relays the sensory information to the brain and its cerebral cortex. In addition, it generates nerve impulses in nerves that control the muscles and the viscera, both through reflex activities and through voluntary commands from the cerebrum. 17 inches long.
Ramon y Cajal
father of modern neuroscience
jet lag
fatigue and sleep disturbance resulting from disruption of the body's normal circadian rhythm as a result of jet travel
progestins
female hormones generated in the ovaries
rods and cones
first layer of retina
ventricles
fluid-filled spaces that cushion the brain.
LIS1
gene that helps tell the brain how to grow. People with mutations in this gene have smoother brains than normal and may have seizures. Severe intellectual disability is also common.
conditioning
generally, learning in which certain experiences make certain behaviors more or less likely; there are two forms of this
acute phase response
generates the symptoms we have all felt (fever, aches and pains, sleepiness, loss of appetite, disinterest).
presenelin 1 and 2
genes which encode enzymes that break the precursor protein down, when mutated, cause early-onset Alzheimer's in some families.
VIPR2 mice
genetically engineered mice in which genes expressed in the suprachiasmatic nucleus are "knocked out" to show how jet lag affects them.
heat-shock proteins
guide damaged proteins to where they can be repaired or harmlessly degraded, thus protecting cells from toxicity or dysfunction
"positive" symptoms of schizophrenia
hallucinations, delusions, and confused thinking.
scleroses
hardened patches of tissue, such as those found in patients with MS.
cerebral nuclei
helps coordinate muscle movements and reward useful behaviors
hypertension
high blood pressure; can happen due to an overexposure to glucocorticoids as is the case in chronic stress.
ghrelin
hormone secreted by empty stomach; sends "I'm hungry" signals to the brain
thyroid hormones
hormones produced by the thyroid gland primarily responsible for regulation of metabolism. Receptors for these can be found in the brain.
sex hormones
hormones that regulate the development and functioning of reproductive organs and that stimulate the devolopment of male and female sexual characteristics: testosterone, estrogen, progesterone
molecular neuropharmacology
how drugs affect the functioning of neurons in the nervous system, providing a new understanding of the mechanisms of addiction.
aphasia
impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).
"negative" symptoms of schizophrenia
inability to experience pleasure and lack of motivation.
gaseous neurotransmitters
includes carbon monoxide and nitric oxide. Are produced by enzymes in the brain and diffuse when necessary.
hindbrain
includes the pons, medulla oblongata, and cerebellum
hyperalgesia
increased sensitivity to pain. There is a lowering of the pain threshold, an increase in the intensity of pain, and sometimes both a broadening of the area over which pain is felt or even pain in the absence of noxious stimulation. This can be a major clinical problem. It involves sensitisation of the peripheral receptors as well as complex phenomena at various levels of the ascending pain pathways. These include interaction of chemically mediated excitation and inhibition. This is observed in chronic pain states results from the enhancement of excitation and depression of inhibition. Much of this is due to changes in the responsiveness of the neurons that process sensory information. Important changes occur in the receptor molecules that mediate the action of the relevant neurotransmitters.
phonemes
individual letter sounds
olfactory cortex
inferior surface of frontal lobe; conscious/unconscious responses to odors are initiated here
inhibitory interneurons
inhibits motor neurons through an inhibitory synapse. They are small neurons with short pathways usually found in the central nervous system. These migrate tangentially across the brain during development.
adrenal medulla
innermost part of the adrenal gland where norepinephrine is secreted during acute stress
periodic limb movements
intermittent jerks of the legs or arms that occur as the individual enters slow wave sleep. These movements can cause arousal from sleep. Commonly found in Parkinson's patients.
cyclic GMP
involved as second messengers in signal transduction from hormones to intracellular enzymes; holds ion channels open when dark.
parietal lobes
involved with sensory processes, attention, and language. Damage to the right side of these lobes can result in difficulty navigating spaces, even familiar ones. If the left side is injured, the ability to understand spoken and/or written language may be impaired.
Blood-Oxygenation-Level-Dependent signal (BOLD)
keeping track of hemoglobin to measure ratio of oxygenated to deoxygenated blood used in fMRI.
expanded triplet repeat
kind of molecular stutter in the DNA. This abnormal gene codes for an abnormal version of the protein called huntingtin in patients with Huntington's.
forebrain
largest, most complicated, and most advanced of the three divisions of the brain; comprises the thalamus, hypothalamus, limbic system, basal ganglia, corpus callosum, and cortex
neural signature of dyslexia
left hemisphere, two posterior (pariento-temporal, occipital-temporal) and left inferior frontal (broca's area)
surface dyslexia
less common, difficulty with visual retrieval, seen in reading exception words with unusual letter-‐ sound combo (pint, yacht, jelly)
meninges
lining of the brain.
retrograde amnesia
loss of memory for events that occurred before the onset of amnesia; eg a soldier's forgetting events immediately before a shell burst nearby, injuring him
local anesthesia
loss of sensation in a limited area of a person's body; used to prevent pain during diagnostic procedures, labor, and surgical operations.
sensory neuropathy
loss of sensation; pain; abnormal sensation; complete or partial loss of sensitivity to touch and temperature is common; can cause atrophy of the small muscles of the hands and feet.
continuous positive airway pressure
low pressure oxygen continuously blown to keep airway from collapsing in patients with sleep apnea.
autonomic nervous system
made of neurons connecting the CNS with internal organs. Divided into the sympathetic and parasympathetic branches.
somatic nervous system
made up of neurons connecting the CNS with the parts of the body that interact with the outside world. Innervates voluntary, skeletal muscles.
androgens
male sex hormones
amphetamines
man-made chemicals that include "Dexedrine", "Speed", and the methamphetamine derivative called "Ecstasy". These drugs act in the brain by causing the release two naturally occurring neurotransmitters. One is dopamine - which probably explains the strong arousal and pleasurable effects of amphetamines. The other is serotonin - which is thought to account for their ability to cause a sense of well-being and a dream-like state that can include hallucinations.
perirhinal cortex (PRH)
mediates the sense of familiarity about the past .
antiretroviral treatment
medications that treat HIV by preventing the growth of the virus.
oval window
membrane at the enterance to the cochlea through which the ossicles transmit vibrations and separates the fluid-filled inner ear from the air-filled outer ear. Transmits pressure waves to the snail-shaped cochlea.
neuronal networks
memory circuits in the brain that consist of complicated networks of nerve cells
replacement
methods which avoid or replace the use of animals in research, such as tissue culture and computational modeling.
two-point threshold
minimum distance necessary between two points of stimulation on the skin such that the points will be felt as two distinct stimuli. This method involves touching the skin with calipers at two points. Not surprisingly, acuity is greatest in the most densely nerve-packed areas of the body. The threshold is lowest on the fingers and lips.
guidance molecules
molecules that aid in neuronal migration. Include semaphorn, ephrin, and netrin.
alpha motor neurons
motor neurons directly responsible for contracting muscles found in the brain and spinal cord
electrochemical gradient
move charged ions in and out of neurons (that underlie synaptic and action potentials)
radial migration
movement of cells in the developing neural tube from the ventricular zone in a straight line outward toward the tube's outer wall. Occurs in an "inside-out" manner; that is, the cells that arrive the earliest (the oldest ones) form the deepest layer of the cortex, whereas the late arriving (the youngest) neurons form the outermost layer.
tangential migration
movement of cells in the developing neural tube in a direction parallel to the tube's walls
spasticity
muscle stiffness, especially in patients with MS.
TSC1 and TSC2
mutations of these genes lead to tuberous sclerosis complex.
grandmother cells
mythical neurons in the human brain that might respond only when one's grandmother comes into view and must never make a mistake!
nerve terminals
name for the end of the axon and beginning of the synapse
local cerebral blood flow (CBF)
neural activity can be assessed by measuring this; measured in PET.
reuptake
neurotransmitters that can't find an area across the synapse to attach will be reabsorbed by the sending neuron in this process.
REM-suppressive neurotransmitters
norepinephrine, serotonin, GABA, histamine
sleep apnea
occurs as sleep deepens and the airway muscles in the throat relax to the point of collapse, closing the airway. The individual has difficulty breathing and wakes up without entering the deeper stages of slow wave sleep. This condition can cause high blood pressure and may increase the risk of heart attack.
sleep-wake cycle
occurs in a circadian rhythm, with a period of about 24 hrs.
REM behavior disorder
occurs when muscles fail to become paralyzed during REM sleep, As a result, people literally act out their dreams by getting up and moving around. Commonly found in Parkinson's patients.
receptor
on or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone or neurotransmitter.
Carver Mead
one of the 'gurus' of silicon valley in California, coined the description 'neuromorphic engineering' to describe the translation of neurobiology into technology.
peripheral nervous system (PNS)
one of two divisions in the nervous system. Consists of nerves and small concentrations of gray matter that connect with the body below the head.
central nervous system (CNS)
one of two divisions in the nervous system. Includes the forebrain, midbrain, hindbrain, and spinal cord.
morphine and codeine
opioids
mesocortical pathway
originates in the ventral tegmental area, and projects to the frontal cortex and surrounding structures. Some evidence indicates that a malfunction in this dopaminergic pathway might be the cause of some of the symptoms of schizophrenia, such as hallucinations and disordered thinking. Medications that block this pathway reduce psychotic delirium, but also reduce the overall activity of the frontal lobes.
immune system
our first line of defence against malicious invaders. These invaders, viruses, bacteria and yeast, range from common and mild, such as the all too familiar cold, to severe and life threatening, e.g. HIV, meningitis or tuberculosis
external ear
outer structures of the ear that collect sound. Composed of pinna and external auditory canal
phantom limb pain
pain perceived in an amputated section
analgesics
painkillers. The four types are nonopioids, opioids, antiepileptic agents, and antidepressants.
atonia
paralysis of the body's muscles.
external auditory canal
part of the external ear; transmits sound waves from the pinna to the tympanic membrane of the middle ear.
thalamus
passes most sensory information on to the cerebral cortex after helping to prioritize it
Αδ fibres
peripheral afferent fibres that respond to noxious stimuli, they are relatively fast myelinated fibres
neuromuscular junction
point of contact between a motor neuron and a skeletal muscle cell
snare, tagmin and brevin
presynaptic proteins that race around tagging and trapping others, causing the releasable synaptic vesicles to fuse with the membrane, burst open, and release the chemical messenger out of the nerve ending.
feedback loop
principle that regulates the production and secretion of hormones in a chain
reflexive knee movement
produced by a slight stretch of the knee extensor muscles when the physician taps the muscle tendon at the knee.
nigrostriatal pathway
projects axons from the substantia nigra to the striatum (caudate nucleus and putamen), which is involved in motor control. Degeneration of the neurons in this pathway is associated with the trembling and muscular rigidity symptomatic of Parkinson's disease.
interleukins
proteins (cytokines) that stimulate the growth of B and T lymphocytes
developmental dyslexia
reading difficulties that show up when children are first learning to read; due to genetic abnormalites in brain circuits related to the ability to read
primary auditory cortex
receives information related to pitch, rhythm, and loudness.
N-methyl-d-aspartate (NMDA)
receptor that has implications, in developing animals, from learning and memory to development and specification of nerve contacts. During trauma and stroke, this receptor is overstimulated. These are the critical molecular machines that trigger synaptic plasticity.
palpitations
receptors that are found on blood vessels, cause them to constrict and so our blood pressure shoots up, and in the heart, causing it to accelerate and produce these pounding sensations in the chest
optical signal
records how light scatters in response to rapid cellular changes that arise when neurons fire, potentially assessing neural activity lasting milliseconds.
three Rs
reduction, refinement and replacement
corticotropin-releasing hormone (CRH)
released from the hypothalamus and travels to the pituitary gland, where it triggers the release of adrenocorticotropic hormone (ACTh)
Randy Gardner
resolved to try and win his place in the Guinness book of Records by going without sleep for the longest period ever recorded. His ambition was to last 264 hours without sleep - and he did it!
frontal lobe
responsible for initiating and coordinating motor movements; higher cognitive skills, such as problem solving, thinking, planning, and organizing; and for many aspects of personality and emotional makeup.
chorionic villus sampling
sampling of placental tissues for prenatal diagnosis of potential genetic defects, such as Down syndrome.
epidemiologists
scientists studying disease in human populations.
interneurons
second layer of retina
epinephrine (adrenaline)
secreted by the adrenal medulla; they are hormones that help the body deal with stress by increasing blood pressure, heartbeat, and respiration.
deletions
segments of chromosomes, perhaps involving multiple genes, that are missing.
duplications
segments of chromosomes, perhaps involving multiple genes, that are present in more than the usual amount.
ion channels
selectively permeable, water-filled molecular tunnels that pass through the cell membrane and allow ions — electrically charged atoms — or small molecules to enter or leave the cell.
taste buds
sensory organs in the oral cavity that contain the receptors for taste. They are special structures embedded within small protuberances on the tongue called papillae. Other taste buds are found in the back of the mouth and on the palate. Every person has between 5,000 and 10,000 of these. Each one consists of 50 to 100 specialized sensory cells, which are stimulated by tastants such as sugars, salts, or acids.
netrin
signaling molecule first discovered in a worm. Causes chemoattraction in axonal guidance.
joint flexor
skeletal muscle that closes a joint when it is activated
joint extensor
skeletal muscle that opens the joint when that muscle is activated
papillae
small bumps found on the upper surface of the tongue, in which taste buds are embedded in
coronary stents
small metallic springs used to help keep an artery open; clearing clogs in the arteries of the neck regions.
signaling molecules
special molecules that turn on certain genes, and turn off others.
ganglion cells
specialized neurons near the inner surface of the retina. The axons of these form the optic nerve
cannabinoid receptors
specific very widespread receptors that THC binds to (CB1) in limbic system, cortex, motor system, spinal cord, but not much of brainstem
luteinizing hormone (LH)
starts ovulation and turns the follicle into the corpus luteum
developmental neurobiology
studies how brain cells are formed and specialized etc
genetic linkage studies
studies that follow families and large groups of unrelated people diagnosed with specific conditions, making it possible to find the chromosomal location of many genes.
neurogenetics
studies the role of genes in the development and function of the human brain
smart drugs
substances (drugs, supplements, herbal extracts, etc.) that are thought to improve memory.
glucocorticoids
substances that mobilize energy into the bloodstream from storage sites in the body, increasing cardiovascular tone and delaying long-term processes in the body that are not essential during a crisis, such as feeding, digestion, growth, and reproduction. Some of the actions of these substances help mediate the stress response, while other, slower actions counteract the primary response to stress and help re-establish homeostasis. They also affect food intake during the sleep-wake cycle.
seizures
sudden, disorderly discharges of interconnected neurons in the brain that temporarily alter one or more brain functions. They are associated with epilepsy.
axonal guidance
supreme navigational feat, accurate over short and long distances. It is also a very single-minded process for not only is the target cell selected with high precision but, to get there, the growth cone may have to cross over other growth cones heading for different places. Along the path, guidance cues that attract (+) or repel (-) the growth cones help them find their way, although the molecular mechanisms responsible for regulating the expression of these cues remain poorly understood.
decompressive craniectomy
surgical procedure used as a last resort to relieve internal pressure on brain. Part of skull is removed.
implanted pumps
surgically implanted specialized pumps inject drugs directly into a specific part of the body, especially for pain-relieving drug administration into the spine.
cerebral edema
swelling as a result of excess accumulation of water in the brain.
herpes encephalitis
symptom of neonatal herpes that results in mental impairment, blindness, convulsions, and can be fatal
acral lick syndrome
syndrome in dogs who have severely sore paws from compulsive licking.
hydrocortisone and prednisone
synthetic glucocorticoids given to patients with glucocorticoid-induced immunosuppression.
selective serotonin reuptake inhibitors (SSRIs)
targets serotonin and works mainly by interfering with the re-absorption of serotonin in the brain. Selectively inhibits serotonin reuptake and results in potentiation of serotonergic neurotransmissions (Luvox, Paxilo, Prozac, Zoloft)
near infrared spectroscopy (NIRS)
technicians practicing this technique shine lasers through the skull at near infrared frequencies, which renders the skull transparent. Blood with oxygen in it absorbs different frequencies of light from blood in which the oxygen has been consumed. By observing how much light is reflected back from the brain at each frequency, researchers can track blood flow.
chromosome microarrays
technique used to look carefully at the overall chromosome makeup of a person and find out if segments of chromosomes, perhaps involving multiple genes, are missing or present in more than the usual amount
adaptation
temperature receptors are important for this type of sense.
DMD
the X-linked gene responsible for Duchenne muscular dystrophy.
neuromodulation
the action of metabotropic receptors, receptors as adjusting or modulating the vast array of chemical processes going on inside neurons.
acetaminophen
the active ingredient in Tylenol, has analgesic properties but does not reduce inflammation. It is believed to block pain impulses in the brain itself.
ethanol
the active ingredient in alcoholic beverages, is a seductive drug. At first, it reduces anxiety, tension, and behavioral inhibitions. In low doses, it may act as a stimulant, but at higher doses, it acts as a depressant. In both cases, it significantly alters mood and behavior. Too much alcohol can also cause heat loss and dehydration.
tetrahydrocannabinol (THC)
the active ingredient in marijuana, binds to cannabinoid receptors, many of which coordinate movement. This may explain why people who drive after they smoke marijuana are impaired. The hippocampus, a structure involved with memory storage and learning, also contains many receptors for this compound.
drug dependence
the adaptive physiological state that results in withdrawal symptoms when drug use stops.
nicotine
the addicting substance in tobacco, acts through the well-known acetylcholine-nicotinic receptor. This drug can act as both a stimulant and a sedative. It stimulates the adrenal glands, and the resulting discharge of epinephrine causes a "kick" — a sudden release of glucose paired with an increase in blood pressure, respiration, and heart rate. In addition, it releases dopamine in the brain regions that control motivation, which is one reason that people continue to smoke.
intracranial pressure
the amount of pressure inside the skull.
sensory cortex
the area at the front of the parietal lobes that registers and processes body touch and movement sensations
V4
the area of the brain that enables us to perceive colour, though some neuroscientists suspect it is not the only area involved.
neuron
the basic working unit of the brain, a specialized cell designed to transmit information to other nerve cells, muscle, or gland cells. There are around 100 billion in the brain.
silent rehearsal loop
the bit of your brain that you use to say things to yourself.
blood clots
the blocking of vessels in the brain
transient ischaemic attack (TIA)
the blood supply to a part of the brain fails and the supply of ATP is interrupted. Neurons cannot recharge their ionic gradients and so can no longer conduct action potentials. If, for example, the blood supply to the motor cortex of the left hemisphere were to be cut off, the right arm and leg would become paralysed. If the obstruction passes quickly, neurons can again make ATP, recharge their membranes and normal function will resume.
circadian system
the body's natural biological 24-hour clock that regulates our perception of daytime and nighttime.
goosebumps
the bumps created by hairs standing up on the skin in response to cold, fear, etc.
fovea
the central part of the retina, where light is focused (contains only red and green cones)
chromosome 4
the chromosome altered in patients with Huntington's disease.
chromosome 21
the chromosome which is duplicated/altered in patients with Down syndrome. The gene encoding the amyloid precursor protein (APP) is on this chromosome: presenelin 1 and 2.
all-or-nothing
the concept that action potentials don't vary in magnitude, only in how often they occur. Thus, the only way that the strength or duration of a stimulus can be encoded in a single cell is by variation of the frequency of action potentials.
synaptic cleft
the contact point where one neuron communicates with another.
premotor cortex
the cortex that is involved in preparations of movement, less active during actual movement
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy; even during sleep. This division of the autonomic nervous system helps regulate bodily functions and soothe the body once the stressor has passed, preventing the body from remaining in a state of mobilization too long. If these functions are left mobilized and unchecked, disease can develop. Some actions of the calming branch appear to reduce the harmful effects of the emergency branch's response to stress.
neuroscience
the field of study encompassing the various scientific disciplines dealing with the structure, development, function, chemistry, and pharmacology of the nervous system
neurogenesis
the formation of new neurons
nitric oxide
the gaseous neurotransmitter governs erection in the penis. In nerves of the intestine, it governs the relaxation that contributes to the normal movements of digestion. In the brain, it is the major regulator of the intracellular messenger molecule cyclic GMP.
HTT
the gene that is altered in patients diagnosed with Huntington's disease.
neurorealism
the idea that anything neuroscientific must be definitive and true.
Guillain Barré syndrome
the immune system attacks nerves as they emerge from the spinal cord, resulting in this disease.
oxidative distress
the impaired performance of cells caused by too many oxygen molecules in them.
akinesia
the inability to move.
cerebrum
the largest part of the human brain, is associated with higher order functioning, including the control of voluntary behavior. Thinking, perceiving, planning, and understanding language all lie within this structure's control. It is divided into two hemispheres — the right hemisphere and the left hemisphere.
cognitive privacy
the legal problem of how to determine at what point lie detection brain devices invade people's right to privacy or violate their right not to incriminate themselves.
occipital lobe
the lobe that helps process visual information, including recognition of shapes and colors. Vision accounts for the most space devoted to the special senses in the brain.
temporal lobes
the lobes that help process auditory information and integrate information from the other senses.
analgesia
the loss of pain sensation.
glycine
the main inhibitory neurotransmitter of the spinal cord and the brain stem
substance P
the major neurotransmitter of sensory neurons for pain
tau protein
the modified form of this protein is responsible for neurofibrillary tangles in Alzheimer's; found in the cell bodies of neurons.
auditory nerve
the nerve that carries impulses from the inner ear to the brainstem, resulting in the perception of sound. There are 30,000 fibers.
optic nerve
the nerve that carries neural impulses from the eye to the brain. Is formed by axons of the ganglion cells
homeostasis
the normal equilibrium of body function
Jeanne Calment
the oldest known woman who lived until 122
glucose
the oxidation of this molecule provides energy for neurons.
sympathetic nervous system
the part of the autonomic nervous system that mobilizes energy and resources during times of stress and arousal. This division of the autonomic nervous system causes arteries supplying blood to the muscles to relax in order to deliver more blood, allowing greater capacity to act. At the same time, blood flow to the skin, kidneys, and digestive tract is reduced. The stress hormone epinephrine, also known as adrenaline, is quickly released into the bloodstream.
soma (cell body)
the part of the neuron that contains the nucleus and cytoplasm.
light intensity
the perception of movement, depth, perspective, the relative size of objects, the relative movement of objects, shading, and gradations in texture all depend primarily on what?
nociceptor
the peripheral nerve fiber that initially responds to the injury stimulus.
optic chiasm
the point in the brain where the visual field information from each eye "crosses over" to the appropriate side of the brain for processing
cell differentiation
the process by which a cell becomes specialized for a specific structure or function.
electroencephalography (EEG)
the process of recording the electrical activity of the brain through the use of electrodes attached to the scalp.
tolerance
the progressive need for a higher drug dose to achieve the same effect.
capsaicin
the pungent ingredient in hot peppers; can be used as a topical to relieve the sensation of pain in neuropathic patients.
proliferation
the rapid increase in neuronal number
digital coding
the recording, storage, and retrieval of information that uses a sequence of symbols or bytes that are not dependent on the physical characteristics of any one medium. Uses 0's and 1's.
synaptic plasticity
the science of how neurons alter their ability to communicate with one another.
gamma motor neurons
the sensitivity of the muscle spindle organs is monitored by the brain through a separate set of these neurons that control the specialized muscle fibers and allow the brain to fine-tune the system for different movement tasks.
somasthetic areas
the sensory areas receiving from the skin
clomipramine
the serotonergic antidepressant which was the first effective treatment developed for people with OCD.
pinna
the structural part of the external ear, but not the external auditory canal, that collects and funnels the sound into the canal.
neuropharmacology
the study of how drugs affect cellular function in the nervous system, and the neural mechanisms through which they influence behavior.
pallidotomy
the surgical deactivation of the overactive pallidum and subthalamic nuclei, greatly reducing the symptoms of Parkinson's disease in patients who have experienced significant worsening of symptoms and are troubled by the development of drug-related involuntary movements.
motor endplate
the synaptic junction where the structural enlargement of muscle fiber is found
homeostatic system
the system regulating sleepiness and responds to progressively longer wake periods by increasing the urge to sleep
vagus nerve
the tenth cranial nerve that innervates digestive organs, heart and other areas
transcription
the turning on of genes.
positron emission tomography (PET)
the very first functional technique to be developed: one of the most important techniques for measuring blood flow or energy consumption in the brain. This method of measuring brain function is based on the detection of radioactivity emitted when positrons, positively charged particles, undergo radioactive decay in the brain. Small amounts of a radioisotope are introduced into the blood, which then carries the radioisotope to different brain areas. The radioisotope shows up in the brain in proportion to how hard local neurons are working. Computers build three-dimensional images of changes in blood flow based on the amount of radiation emitted in different brain regions. The more brain activity, the more vivid the picture that is created.
myelination
the wrapping of neurons by the extension of glia. Increases the speed at which signals may be sent from one neuron to another by a factor of up to 100x.
David Hubel and Torsten Wiesel
these Nobel Laureates discovered the importance of the critical period in modifying visual circuits, leading to the realization that there is currently no cure for amblyopia in adults. Electrical recordings made from cells in the visual cortex have revealed some amazing properties. These include orientation selectivity, the beautiful columnar organisation of such cells and the plasticity of the system.
cats and monkeys
these animals are researched to provide therapy for strabismus.
pigeons
these birds were researched to discover that dopamine was highly concentrated in the basal ganglia, the part of the brain involved in motor function.
calcium ions
these ions rush in when an action potential courses along an axon releasing Ach.
rats
these rodents are helpful in uncovering changes to the brain as a result of drug addiction.
staining techniques
these techniques have enabled scientists to look at the pathways and connections between different areas of the brain, as well as the neurons that contain and use specific neurotransmitters, so that a roadmap of the brain's connections could be drawn.
malignant brain tumors
these tumors can originate in the brain or spread to the brain from other parts of the body, a condition that becomes potentially lethal.
neural plate
thickened ectodermal cells around the notochord
ganglion cells
third layer of retina
left posterior temporal lobe
this brain area contains a sensory motor circuit for speech which is thought to translate between speech recognition and speech production systems. The circuit is involved in speech development and is thought to support verbal short-term memory.
Vincent van Gogh
this impressionist painter suffered from severe depression.
buprenorphine
this medication causes a weaker effect on opioid receptors than methadone and creates only a limited high, which deters an addict from abusing the medication itself.
neuroendocrine system
this stress communication system maintains the body's internal functioning. Various stress hormones travel through the blood and stimulate the release of other hormones, which affect bodily processes such as metabolic rate and sexual function.
voluntary nervous system
this stress communication system sends messages to muscles so that we may respond to sensory information.
Kabuki syndrome
this syndrome is marked by congenital intellectual disabilities along with certain abnormal facial features.
transcranial magnetic stimulation (TMS)
this technique works by inducing electrical impulses in the brain. This is accomplished by altering magnetic fields through the use of an electromagnetic coil that emits powerful magnetic pulses while held against the scalp. Repetitive uses of the technique are being used to investigate the role of specific brain regions during behavior, and it can be combined with other neuroimaging techniques.
critical periods
times during which certain environmental influences can have an impact on the development of the infant
learning rules
train networks do so by modifying the strength of the connections between the neurons, a common one being a rule that takes the output of the network to a given input pattern and compares it with the desired pattern. Any 'error' in the comparison is then used to adjust the weights of the connections to achieve a closer output to the desired one. The network gradually reduces the error signal to a minimum. This works - but only slowly
adrenocorticotropic hormone (ACTh)
travels in the blood to the adrenal glands, where it stimulates the release of cortisol.
targeted therapy
treatment aimed at the biologic characteristics of tumors. They include vaccines created from the patient's own tumor combined with substances that boost the immune system or kill tumor cells; monoclonal antibodies; anti-angiogenic therapy; immunotherapy; gene therapy; and several approaches for a targeted delivery of antibodies, toxins, or growth-inhibiting molecules that attach specifically to the tumor cells and interfere with their growth.
gene therapy
treatment that delivers bioengineered genes to the cancer cells on a tumor to kill them.
anti-angiogenic therapy
treatment that restricts the blood supply of a brain tumor.
immunotherapy
treatment that uses the body's own immune system against the brain tumor.
gonadotropin releasing hormone (GnRH)
tropic peptide hormone synthesized and released from neurons within the hypothalamus. It constitutes the initial step in the hypothalamic-pituitary-gonadal axis by acting on the pituitary.
primary brain tumors
tumors that develop within brain tissue. Such tumors can spread throughout the brain, and may be benign or malignant.
metastatic (secondary) brain tumors
tumors that spread from other parts of the body through the bloodstream and enter the brain.
cranial nerves
twelve pairs of nerves that carry messages to and from the brain with regard to the head and neck (except the vagus nerve). In taste, the sensory cells stimulate a nerve to send it to taste regions in the brain.
beta and gamma secretases
two proteases that cleave APP, producing amyloid proteins.
Lewy body disease
type of dementia where Lewy bodies (microscopic protein deposits) damage brain cells over time, signs gradually develop and include impairment in alertness and attention, vivid visual hallucinations, and motor impairment as seen in Parkinson's.
reductionist agenda
ultimate truth lies embedded in the molecular constituents of the nervous system - with new DNA and proteomic technologies promising fuller explanations of the brain that will finesse the problems faced by other neuroscientists.
emotional memory
unconscious, implicit memory for emotions, storage of actual feelings in emotion associated with an event. Stored in amygdala, hypothalamus, and sympathetic nervous system.
marginal zone
undifferentiated cells enter from ventricular zone and become either neurons or glial cells in this structure (outer surface)
refinement
use of methods that alleviate or minimize potential pain, suffering or distress, and enhance animal welfare for the animals used.
reduction
use of methods that enable researchers to obtain comparable levels of information from fewer animals, or to obtain more information from the same number of animals.
Descartes
used a hydraulic metaphor to explain how the "humours" of the brain moved the muscles - a metaphor borrowed from the water engineering he saw in the gardens of French chateaux
diffuse optical tomography
used to create maps of brain activity from recordings using near infrared spectroscopy.
deep-brain stimulation
utilizes electrodes surgically implanted in the brain and a battery-powered neurostimulator surgically implanted in the chest. Wires under the skin connect the two implants, and the neurostimulator sends electrical signals to the brain. Used to relieve the symptoms of Parkinson's disease, and shows promise as a therapy for treatment resistant depression.
Herpes simplex and adenovirus
vectors that have been evaluated in early-stage human trials for treating brain tumors.
shingles
viral disease that affects the peripheral nerves and causes blisters on the skin that follow the course of the affected nerves
leukocytes
white blood cells that attack foreign bodies
Alan Hodgkin and Andrew Huxley
won the Nobel Prize for discovering the mechanism of transmission of the nerve impulse. They used the "giant axon" of the squid in studies at the Plymouth Marine Biology Laboratory
