Neuroscience good to know
What are the main output areas of the basal ganglia?
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What structures are included in the basal ganglia?
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Based on what you know about human memory, what advice can you offer to students studying for final exams?
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Distinguish between declarative memory storage and nondeclarative (procedural) memory.
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What approaches are used to assess hippocampal involvement in memory consolidation?
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What are the brain and behavioral symptoms of Alzheimer's disease? Briefly summarize the current view on the causes of Alzheimer's disease.
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Where would you expect to find engrams (stored representations of memories) for: declarative and procedural memories?
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More indepth explanation of barriers preventing regeneration?
1)Glutamate overstimulation -->Too much neurotransmitter leads to decrease in effectiveness of anti-apoptotic molecules which leads to release in cytochrome c which then leads to caspase 3 → causing neuronal death. 2)Apoptosis and Neuronal Death --->Activated glial cells are not affected therefore glial cells flourish while neuronal cells die. 3)Glial Scarring --->Oligodendrocytes (NogoA), microglia, astrocytes produce growth inhibiting molecules and block axons from growing outside of the glial scar. 4)Conditions do not resemble those of developmental conditions. --->Not enough neurotrophins, adhesion molecules (such as N-CAM), and growth factors (such as BDNF). 5)Inflammatory cytokines at the site of the injury.
Other than functional reorganization of intact neurons, what are the three types of repair in response to damage to the nervous system?
1)Peripheral nerve restoration (or central nerve cells whose projections are in the periphery). 2)Restoration of central nerve cells. 3)Neurogenesis (wholesale genesis of new neurons).
List the steps involved in chemical neurotransmission, from the synthesis of neurotransmitter.
1)Transmitter is synthesized and then stored in vesicles 2)An action potential invades the presynaptic terminal 3)Depolarization of presynaptic terminal causes opening of voltage-gated Ca+ channels 4)Influx of Ca+ through channels 5)Ca+ causes vesicles to fuse with presynaptic membrane 6)Transmitter is released into synaptic cleft via exocytosis 7)Transmitter binds to receptor molecules in postsynaptic membrane. 8)Opening or closing of postsynaptic channels. 9)Postsynaptic current causes excitatory or inhibitory postsynaptic potential that changes the excitability of the postsynaptic cell 10)Removal of neurotransmitter by glial uptake or enzymatic degradation 11)Retrieval of vesicular membrane from plasma membrane
A significant barrier to the reconstitution of injured brain (or spinal cord) regions is A. All of these B. our very limited understanding of how to modify neural stem cells to produce specific populations of adult neurons. C. the limited amounts of natural neurogenesis that occur in mammals. D. the inability of newborn adult neurons to form long-range connections.
A
Focal application of a GABA receptor agonist within the substantia nigra pars reticulata would most likely A. result in involuntary saccadic eye movements. B. result in abnormal limb movements. C. produce a temporary thought disorder. D. lead to degeneration of the globus pallidus.
A
Functional neuroimaging studies (by Drevets and Raichle) of subjects with unipolar depression have shown A. increased blood flow in the amygdala and specific areas in the prefrontal cortex. B. decreased blood flow in the amygdala and specific areas in the prefrontal cortex. C. no difference in blood flow patterns between depressed and non-depressed subjects. D. abnormal blood flow in specific prefrontal cortical areas that continues even after resolution of depressive symptoms.
A
Golgi tendon organs are most sensitive to A. tension. B. vibration. C. motion. D. deep pressure.
A
In addition to their traditional motor program selection and implementation functions, the basal ganglia are also thought to be involved in A. All of these. B. mood changes. C. disorders such as Tourette's syndrome and schizophrenia. D. drug-seeking behaviors.
A
In the process of normal aging, A. the weight of the brain decreases. B. the number of synapses increases. C. there is no evidence of shrinkage of the brain. D. neurogenesis increases.
A
Listed below are the events that occur during basal ganglia functioning. 1. Disinhibition of ventral anterior and ventral lateral thalamic nuclei 2. Inhibition of globus pallidus 3. Excitation of corpus striatum Which of the following is the correct sequence of these events? A. 3; 2; 1 B. 2; 3; 1 C. 3; 1; 2 D. 1; 2; 3
A
One of the outputs of the basal ganglia, the substantia nigra pars reticulata, is most similar in its function to the A. globus pallidus. B. caudate. C. putamen D. corpus striatum.
A
Priming A. includes the propensity to choose words from a word-list despite having no recollection of having recently encountered those words. B. refers to a memory store that is infallible because it involves no conscious decision making. C. is very susceptible to disruption via injury or aging. D. refers to the enhancement of memory recall by the deliberate rehearsal of earlier events in the day.
A
Research on spatial learning in rats trained on the Morris water maze task revealed which of the following? A. Healthy rats are able to make associations between visual cues outside the water tank and the location of a submerged resting platform. B. The principal effect of hippocampal lesions is that rats require many more trials to learn the location of a submerged platform. C. Some strains of rats are able to swim directly to a submerged platform without training. D. After training, rats remember the location of a submerged platform for just a few days.
A
Serotonin reuptake blockers such as fluoxetine (Prozac) are used clinically A. as antidepressants. B. to treat hypertension. C. to treat generalized anxiety D. as antipsychotics.
A
The deepest stage of sleep is _______ sleep. A. slow-wave B. stage I C. spindle-wave D. REM
A
The entrainment of our body's circadian rhythm with environmental light-dark cycles is mediated by A. specialized retinal ganglion cells. B. cone photoreceptors in the retina. C. photoreceptors in the pineal gland. D. rod photoreceptors in the retina.
A
The loss of memories that had been stored before an injury or the onset of an illness is called A. retrograde amnesia. B. semantic amnesia. C. anterograde amnesia. D. Korsakoff's syndrome.
A
The main reason that rods are more sensitive to light than cones is that A. the rod transduction mechanism provides greater signal amplification. B. the photopigment of rods is much more sensitive to light than the photopigment used in cones. C. the eye contains 1000 times as many rods as cones. D. the rod is sensitive to a much broader range of wavelengths.
A
The movement of what ion is reflected in the rising phase of the action potential? Choose the correct option. A. Inward Na+ B. Outward K+ C. Inward K+ D. Outward Na+
A
The painful sensations induced by capsaicin are mediated by A. TRPV1. B. substance P receptors. C. serotonin receptors. D. habanero receptors.
A
The responses of cortical cells are tuned to A. bars or edges in a particular orientation B. color. C. movement of a bar or edge. D. a boundary between two hues.
A
The resting membrane potential is not exactly equal to the Nernst potential for potassium because A. the membrane has some resting permeability to ions other than potassium. B. all of these are correct. C. rapid fluctuations in membrane potential prevent accurate measurements. D. potassium does not contribute to the resting membrane potential.
A
The sleep-promoting substance melatonin A. reaches a maximum blood concentration between 2:00 and 4:00 A.M. B. is produced by the pituitary gland. C. provides dramatic relief in cases of fatal familial insomnia. D. is synthesized from the chemical precursor tyrosine.
A
The superior colliculus A. coordinates head and eye movements. B. controls pupil dilation. C. detects motion. D. directs circadian rhythms.
A
Touch receptors such as Meissner's corpuscles deliver information to the central nervous system rapidly via _______ fibers. A. Abeta B. C C. Aalpha D. Adelta
A
Typically, neurons firing action potentials encode a signal's intensity by A. changing the frequency of their action potentials. B. firing at precise moments so as to signal different sized signals. C. changing the size of their action potentials. D. sending signals of different sizes down different axonal branches.
A
What is meant by the action potential threshold? Choose the correct option. A. Critical level of depolarization required to trigger an action potential. B. Critical level at which electrical current is injected through a microelectrode. C. Critical level of hyperpolarization required to trigger an action potential. D. The action potential threshold is the same as the generator potential.
A
What type of information does the dorsal column-medial lemniscal pathway carry? A. Touch and proprioception B. Pain and proprioception C. Pain and temperature D. Touch and temperature
A
Which of the following does not provide inputs to the amygdala? A. Caudate putamen B. Hypothalamus C. Olfactory cortex D. Orbital prefrontal cortex
A
Which of the following is an accepted criterion for defining a molecule to be a neurotransmitter? A. All of these. B. It must exert an effect on the postsynaptic cell. C. It must be released in response to presynaptic electrical activity. D. It must be present in the presynaptic terminal.
A
Which of the following is not a process that would likely contribute to those changes in neural circuitry that constitute a critical period? A. Neurogenesis B. Remodeling of axonal arbors C. Synapse elimination D. Neurotransmitter receptor activation
A
Which of the following is not an aspect of long-term memory? A. The utilization of sensory-modality specific "memory registers" B. Consolidation of information C. Long-term changes in synaptic connectivity D. Storage of information for years or decades
A
Which of the following is not integral to the action potential waveform? A. An initial decrease in the potassium current B. A change in permeability of the membrane to sodium C. A transient increase in the sodium current D. A change in permeability of the membrane to potassium
A
Which of the following represents the most direct pathway for the transmission of visual information from the eye to the brain? A. Photoreceptor → bipolar cell → ganglion cell → brain B. Photoreceptor → bipolar cell → amacrine cell → ganglion cell → brain C. Photoreceptor → bipolar cell → amacrine cell → brain D. Photoreceptor → horizontal cell → ganglion cell →brain
A
Which of the following sensory systems has not (yet) been shown to exhibit a developmental critical period? A. Proprioceptive B. Somatic sensory C. Auditory D. Visual
A
Which of the following statements about synapse elimination and grey matter volume is/are true? A. All of these are true. B. The decline in cortical synapses roughly corresponds to a generalized human "critical period." C. Synaptic decline is more prolonged in higher order (association) cortical areas than in primary sensory areas. D. The number of cortical synapses declines during adolescence and then roughly plateaus thereafter.
A
Which of the following statements about the medium spiny neurons is false? A. Each one densely innervates 100 to 200 pallidal neurons. B. They outnumber their target neurons in the globus pallidus by about a factor of 1,000. C. They are GABAergic. D. They are the major output of the striatum.
A
Which of the following statements is false? A. The major outputs of the basal ganglia are from the putamen. B. The corpus striatum includes the caudate and putamen. C. The pallidum includes the globus pallidus and the substantia nigra pars reticulata. D. The basal ganglia include the caudate, putamen, and globus pallidus.
A
Which of the following was shown to eliminate the early inward current in squid giant axons? A. Removal of external sodium B. Removal of external potassium C. Removal of all external cations D. Doubling of external sodium
A
_______ are sensitive to light touch. A. Meissner's corpuscles B. Merkel's discs C. Meissner's corpuscles D. Pacinian corpuscles
A
What is a critical period? Give an example.
A critical period is a restricted developmental period during which the nervous system is sensitive to the effects of experience. Example: somatosensory map, rat whiskers during critical period, language.
The axons transmitting cortical signals to the basal ganglia A. arise from cortical patches that that project exclusively to the basal ganglia B. carry information whose nature is poorly understood. C. arise almost entirely from axons of the corticothalamic tract. D. arise almost entirely from axons of the corticospinal tract.
A,B
Which of the following is a symptom of clinical depression? Check all that apply. A. Poor concentration B. Disordered sleeping (hypersomnia, insomnia) C. Disordered eating D. Feelings of despair
ALL OF THESE
What kinds of activities decrease neurogenesis?
Aging Drug/alcohol use No sleep Fatigue
Scotopic Vision
At the lowest levels of illumination, only the rods are activated. Scotopic vision is the vision of the eye under low light conditions.
Describe the sages of the sleep cycle?
Awake state: beta waves or alpha waves if eyes are closed. Stage 1: Theta waves Stage 2: Theta waves (sleep spindles: larger spindles associated with higher IQs) Stage 3&4:Delta Waves (SWS; more pronounced at beginning of sleep). REM Sleep: Beta Waves (more pronounced at end of sleep, unless sleep deprived). People go through roughly 4-5 cycles each night (one cycle is around 90 minutes long).
A response to a _______ constitutes a conditioned fear response in the rat. A. smell paired with a noxious food B. tone paired repeatedly with a foot shock C. rubber snake placed in its cage D. foot shock given intermittently
B
Hebb's postulate A. implies that co-activated synaptic contacts will be strengthened and others weakened. B. All of these C. was based on the voltage-dependent properties of the NMDA receptor. D. is an extension of his theory of learning and memory.
B
How do action potentials differ from passively conducted electrical signals? Choose the correct option. A. Action potentials occur only in nerve cells; passively conducted signals occur only in muscle cells. B. Action potentials are signals of fixed size and duration; passively conducted signals are not signals of fixed size and duration. C. Action potentials diminish over distance; passively conducted signals do not diminish over distance. D. Action potentials are transmitted over short distances; passively conducted signals are conducted over long distances.
B
In response to the suturing of an eyelid, it was found that A. neural cell death occurred throughout the sutured animal's visual cortex. B. suturing had dramatic effects on kittens but very little effect on adult cats. C. neural cell death occurred specifically in the areas of the animal's cortex innervated by the sutured eye. D. the consequences of suturing were similar in kittens and adult cats.
B
Listed below are the individual events that make up chemical synaptic transmission: a. Diffusion of transmitter across the synaptic cleft b. Depolarization of the presynaptic terminal c. Vesicle fusion with plasma membrane d. Opening of voltage-gated ion channels e. Activation of presynaptic, calcium-sensitive proteins Which of the following is the correct sequence of these events? A. a; b; c; d; e B. b; d; e; c; a C. e; d; b; c; a D. b; e; d; c; a E. a; b; d; e; c
B
Patient S.M., who suffered selective bilateral damage to the amygdala, exhibited A. deep sadness. B. an absence of fear. C. heightened fear. D. a predisposition to outbursts of anger.
B
Rats completely deprived of sleep A. show a specific problem solving deficit after several weeks. B. will die within a few weeks. C. can live for several months if carefully fed and watered. D. exhibit extreme aggression towards other rats.
B
Slow-wave sleep A. is characterized by sleep-spindles. B. includes stage III and stage IV sleep. C. is characterized by rapid eye movements. D. occurs only once a night.
B
Summation of synaptic potentials in space and time has what effect? Choose the best option. A. Permits a neuron to integrate all EPSPs B. Permits a neuron to integrate electrical information being conveyed at all excitatory and inhibitory synapses. C. Silences the neuron. D. Permits a neuron to integrate all IPSPs.
B
The most plausible theory for the decline in plasticity that signals the end of a critical period is the A. internalization of NMDA receptors. B. modification of histone proteins in ways that hinder future transcription events. C. unique elevations of calcium that are seen only during the critical period. D. internalization of GABA receptors.
B
The primary input to the striatum is from A. cerebellar cortex. B. cerebral cortex. C. the thalamus. D. the globus pallidus.
B
The primary or most proximate event that accounts for light-induced hyperpolarization of photoreceptors is A. a sudden increase in the concentration of cAMP, leading to activation of potassium channels. B. a rapid fall in the concentration of cGMP, leading to closure of Na+/Ca2+ channels. C. light-induced photoisomerization of membrane-bound calcium channels. D. the gating of ion channels by released retinal monomers.
B
The reticular activating system A. is a reticular or mesh-like network that wraps around the cerebrum. B. includes a group of brainstem cholinergic neurons that induces wakefulness. C. is a region of forebrain that activates the rest of the brain. D. is a thalamocortical loop involved in attention.
B
The synaptic potential A. propagates along axons. B. makes communication between nerve cells possible. C. determines the cell's resting potential. D. occurs only in response to external stimuli.
B
Which of the following best describes nerve cells? A. Nerve cells are exceptionally good conductors of electricity (much better than copper wires). B. In comparison to copper wires, nerve cells are relatively poor conductors of electricity. C. Nerve cells are unable to conduct electricity under any circumstances. D. Nerve cells are similar in their electrical conduction properties to copper wires.
B
Which of the following best describes the response of an off-center ganglion cell sitting on or near an edge (dark on one side, light on the other)? A. The cell would fire most strongly if the edge ran through the exact center of the cell. B. The cell would respond most strongly to this stimulus with its off-center sitting on the dark side of the border and just barely touching the border. C. Illumination of the entire receptive field would provide a purely inhibitory signal to the cell. D. The cell would fire most strongly with its entire receptive field on the dark side of the border.
B
Which of the following explains the unidirectional propagation of action potentials? A. Sufficient "leakiness" of the axons, such that backward propagation of action potentials is prevented B. The presence of a refractory period at a location where an action potential has just passed C. The voltage dependence of the potassium channels D. The voltage dependence of the sodium channels
B
Which of the following is the correct definition of working memory? A. Holding information for years B. Holding and mentally manipulating information in some way C. Using engrams to retain information D. Holding information for several days
B
Which of the following statements about neurogenesis in the forebrain of songbirds is correct? A. Forebrain neurogenesis has been demonstrated to be both necessary and sufficient for the learning of new songs. B. Some birds may replace most of the neurons in multiple song control centers several times over a lifetime. C. New neurons are found in the forebrains of only those bird species that learn new songs each year. D. Each year, newborn neurons replace the entire population of all the old song-related neurons.
B
How would you test for a critical period?
Block or mimic
Action potentials are generated A. only after all of the sodium channels are open. B. intermittently, but usually when the membrane potential exceeds threshold. C. only when the cell reaches threshold. D. at most subthreshold voltages.
C
An advantage of electrical synapses is: A. transmission between cells is bidirectional B. electrical activity among populations of neurons can be synchronized C. all of these are advantages. D. transmission across these synapses is incredibly fast
C
Blocking voltage-gated Ca++ channels located in the preysynaptic membrane will: A. have no effect. B. result in an EPSP. C. inhibit neurotransmitter release. D. promote neurotransmitter release.
C
Cocaine acts A. as an MAO inhibitor. B. by blocking serotonin reuptake. C. by blocking dopamine reuptake. D. on GABA receptors.
C
Endocytosis is A. the fusion of gap junction proteins at electrical synapses. B. fusion of a vesicle with the cell's plasma membrane, so that neurotransmitter can be released. C. budding off of vesicles from the cell's plasma membrane, so that vesicles can be recyled. D. synchronized release of neurotransmitter quanta.
C
Experimentally-induced strabismus helped to confirm the role of correlation in synaptic wiring because the A. cat animal model revealed for researchers changes in ocular dominance across area V1. B. activity in the two eyes was poorly correlated because of the strabismus. C. All of these. D. total activity in the two eyes was about the same.
C
Gap junctions (electrical synapses) A. are found only where there are large gaps between nerve cells. B. are used to pass chemical neurotransmitters. C. have larger pores than voltage-gated ion channels. D. are far more numerous than chemical synapses.
C
Henry Head, who had an idiosyncratic approach to studying peripheral nerve regeneration, is most noteworthy for his A. attaching distal nerves to central nerve tracts. B. applying nerve growth factor to the distal ends of cut nerves. C. performing regeneration experiments on himself. D. following regeneration for several decades.
C
Hubel and Wiesel's discovery of a critical period in visual system development was based on their observations of _______ during this period. A. changes in orientation selectivity B. the diversity of neuronal cell types formed C. changes in ocular dominance D. the number of cortical layers formed
C
If humans were placed in a cave and deprived of all time clues, they would A. sleep in brief bouts, like a giraffe does. B. quickly go mad. C. begin free-running, (i.e., their internal clock would operate on a cycle in approximately a 24-hour time cycle). D. maintain an essentially perfect 24-hour sleep-wake cycle for several months.
C
In associative learning studies of monkeys, dopaminergic neural activity in the ventral tegmental area of subjects that had been successfully conditioned to a stimulus showed A. decreased activity when they were given a reward. B. decreased activity in response to the conditioned stimulus. C. decreased activity when the predicted reward was withheld. D. increased activity when they were given a reward.
C
The different electrical signals occurring in nerve cells are caused by A. movements of charged proteins within the cell membrane. B. negative charges bound to the inner and outer sides of the cell membrane. C. fluxes of ions across the cell membrane. D. positive charges bound to the inner and outer sides of the cell membrane.
C
The extent to which stem cells in the vertebrate brain give rise to neurons varies depending on A. species. B. brain region. C. All of these D. specific conditions such as injury and seasonal changes.
C
The membrane potential is generated by A. repulsion of positive and negative charges. B. the greater mobility of small ions. C. diffusion of ions down a concentration gradient. D. the selectivity of the membrane to pass positive charges only.
C
The two main families of neurotransmitter receptors are _______ and _______. A. voltage-gated; voltage-modulated B. excitatory; inhibitory C. ionotropic; metabotropic D. ligand-gated; ion-gated
C
What neurotransmitter is used by nearly all excitatory neurons in the CNS? A. Acetylcholine B. GABA C. Glutamate D. Dopamine
C
Which of the following brain regions is not thought to be involved in declarative memory? A. Hippocampus B. Hippocampal gyrus C. Basal ganglia D. Superior temporal lobe
C
Which of the following brain structures have been identified as primary sites where neuronal activity is altered by drugs of abuse? A. Hippocampus and parahippocampal gyrus B. Amygdala and orbital frontal cortex C. Ventral tegmental area and nucleus accumbens D. Cingulate cortex and nucleus accumbens
C
Which of the following is an important neurotransmitter involved in pain perception? A. Serotonin B. Enkephalins C. All of these D. Substance P
C
Which of the following is not a catecholamine? A. Epinephrine B. Norepinephrine C. Histamine D. Dopamine
C
Which of the following is not an example of declarative memory? A. Remembering your friend's phone number B. Remembering what you had for dinner C. Remembering how to ride a bike D. Remembering the scene of an accident
C
Which of the following is not one of the main repair processes that normally occur in mammals when nervous tissue is damaged? A. Restoration of damaged central neurons B. Long-range regrowth of damaged axons in the peripheral nervous system C. Long-range regrowth of damaged axons in the central nervous system D. Neurogenesis
C
Which of the following statements about the clinical case of H.M. is false? A. H.M.'s nondeclarative memory was intact. B. It showed that bilateral medial temporal structures are important in the formation of declarative memories. C. H.M.'s intellectual functions, as measured by intelligence tests, sharply declined after his surgery. D. H.M. had a profound loss of declarative memory functions.
C
While the nature of adenosine's actions on central circuits is not well understood, adenosine is thought to have an inhibitory or relaxing effect because of which of the following observations? A. Its ability to block the reuptake of inhibitory transmitters B. Its presence in many inhibitory neurons C. The consequences of xanthine (e.g., caffeine) blockade of adenosine receptors D. Its actions as a cofactor at glycine receptors
C
Peptide transmitters are synthesized in the ______, while small-molecule transmitters are synthesized within ________.
Cell body; presynaptic terminals
_________defines the time required for electrical information to travel from one end of an axon to the other.
Conduction velocity
Draw a sketch of the primary visual pathway. Label the essential components.
Cornea, aqueous humor, lens, vitreous humor, retina, optic nerve, optic chiasm, optic tract, dorsal lateral geniculate nucleus in thalamus, optic radiation, primary visual cortex (V1).
Activation of the visceral component of the sympathetic nervous system as it relates to emotional processing A. promotes the buildup of the organism's metabolic reserves. B. is an all-or-none phenomenon, with resultant widespread activity. C. none of these. D. results in specific responses associated with different emotional states.
D
Afferent fibers from the periphery that carry nociceptive information terminate on neurons in the A. medulla. B. cerebellum. C. brain stem. D. dorsal horn cells of the spinal cord.
D
Antihistamines make people drowsy because they A. inhibit the cholinergic nuclei in the brainstem. B. mimic noradrenaline and serotonin at several metabotropic receptors. C. excite several classes of neurons in the raphe. D. block the effects of tuberomammillary hypothalamic neurons.
D
Based upon the distribution of endocannabinoid receptors in the brain, it can be surmised that these compounds have a likely influence on A. neocortex. B. basal ganglia. C. the hippocampus. D. All of these brain regions.
D
Glutamate is A. an essential amino acid. B. the least commonly used neurotransmitter in the brain. C. co-released with GABA. D. neurotoxic at high concentrations.
D
Klüver-Bucy syndrome is characterized by A. improved memory. B. extreme fear. C. increased sexual behaviors. D. visual agnosia, increased oral behaviors and increased sexual behaviors. Increased oral behaviors.
D
Low-frequency stimulation results in: A. localized increases in Ca++ in the presynaptic terminal; release of small molecule neurotransmitters and neuropeptide co-transmitters B. increases in Ca++ throughout the presynaptic terminal; release of small molecule neurotransmitters and neuropeptide co-transmitters C. increases in Ca++ throughout the presynaptic terminal; preferential release of small molecule neurotransmitters D. localized increases in Ca++ in the presynaptic terminal; preferential release of small molecule neurotransmitters
D
Nondeclarative memory includes A. Remembering what you had for dinner B. the conscious retrieval of information. C. Remembering that a wrench is a tool D. the learning of motor skills.
D
Parkinson's disease is associated with loss of dopaminergic neurons in the A. putamen. B. globus pallidus. C. caudate. D. substantia nigra.
D
Primary sensory afferent axons have widely varying diameters and their size correlates with the type of receptor to which they are attached. Which of these axons are the smallest and the slowest? A. None of these B. Proprioceptors of the skeletal muscles C. Mechanoreceptors of the skin D. Temperature, pain, and itch
D
Retinal axons project to the A. thalamus. B. superior colliculus. C. hypothalamus. D. All of these.
D
The cells whose axons make up the optic nerve are the _______ cells. A. horizontal B. amacrine C. bipolar D. ganglion
D
The discovery that the brain contains specific receptors for manufactured opiate drugs, such as morphine, implies that the body must make an _______ substance to interact with the same receptors. A. inhibitory B. excitatory C. exogenous D. endogenous
D
The middle temporal lobe (MT) responds selectively to A. none of these. B. faces. C. color. D. to the direction of movement of an edge.
D
The source of projections to the extrastriate cortex originate in A. the LGN. B. deep layers of visual cortex. C. none of these. D. superficial layers of visual cortex.
D
The substantia nigra pars reticulata projects to the A. corpus striatum. B. substantia nigra pars compacta. C. ventral anterior and ventral lateral thalamus. D. superior colliculus.
D
What is resting membrane potential? Choose the correct option A. Generation and conduction of action potential at rest B. Positive charge inside the membrane with respect to outside at rest C. Isolation of the cytosol from extracellular fluid D. Difference in electrical charge across the membrane at rest
D
Which of the following cell types is exquisitely sensitive to experience-driven neuronal inputs during early postnatal life? A. Dopaminergic B. Serotonergic C. Cholinergic D. GABAergic
D
Which of the following correctly describes a critical period? A. Failure to respond typically results in the immediate death of the animal. B. Dendritic branching and synaptogenesis accelerate on a massive scale throughout the CNS. C. Cortical neural networks are connected and activated for the first time. D. Latent, adaptive neural plasticity requires sensory input for its utilization.
D
Which of the following have been observed in studies of sensory cortical plasticity? A. Somatosensory cortex reorganization after limb amputation might contribute to phantom limb pain. B. Requiring a monkey to repeatedly use a digit (finger) can alter its cortical representation. C. If a cortical region is deprived of input, after a while that region begins to respond to nearby regions of the periphery. D. All of these.
D
Which of the following is a reported consequence of traumatic brain injury, such as may result from a concussion or blast injury? A. Headaches B. Early cognitive impairment and dementia C. Appearance of tau protein deposits in the brain D. All of these
D
Which of the following is not a feature of non-REM sleep? A. Decreased blood pressure B. Rolling eye movements C. Decreased body temperature D. Penile erection
D
Which of the following mediate most of the synaptic inhibition in the CNS? A. GABA and acetylcholine B. Glycine and dopamine C. GABA and glutamate D. GABA and glycine
D
Which of the following neurotransmitters are crucially involved in an organism's reward system and is often altered by drugs of abuse? A. Norepinephrine B. Serotonin C. GABA D. Dopamine
D
Which of the following receptor types can be modulated by both barbiturates and benzodiazepines? A. GABAB B. GABAC C. Glycine D. GABAA
D
Which of the following statements about action potentials is false? A. They are all-or-none. B. They boost the spatial spread of electrical signals. C. They occur at threshold. D. They are elicited by hyperpolarization.
D
Which of the following statements about human sleep cycles is false? A. Cortisol level begins to increase toward early morning. B. Growth hormone increases at night. C. Adults, on average, need about 7.5 hours of sleep a night. D. The need for sleep increases with age.
D
Which of the following statements about myelination is false? A. Myelin sheaths are created by glial cells. B. Myelin is absent at the nodes of Ranvier. C. Sodium and potassium channels are clustered at the nodes of Ranvier. D. Myelin serves to sharply increase the time constant of the axon.
D
Which of the following statements about primary somatosensory cortex (S1) is true? A. All of these are true. B. It is organized by receptor type, with a Pacinian area, a Merkel disc area, a temperature area, and a pain area. C. The amount of cortex dedicated to each body part is proportional to its surface area. D. Receptive field properties vary within different subregions of S1.
D
Why is it useful to know the K+ equilibrium potential?
Decreasing or increasing K+ really changes the ion flux and membrane potential. The resting membrane potential is equal to K+ electrochemical equilibrium.
Sketch a typical neuron and label its essential components?
Dendrites (input) Cell Body (organelles, nucleus) Node of Ranvier Axon Terminal Nucleus (neuronal DNA) Axon (transmits info) Myelin Sheath (insulates/protects/rapid transmission) Cytoplasm Membrane (insulator; ion channels) Axon Hillock Axon collaterals Synapse
Merkel
Detect edges, slowly adapting, dermal area
Pacinian
Detect vibrations, rapidly adapting, subcutaneous.
Developmental changes during critical periods?
Developmental Changes: stabilization of synaptic connections and weakening/eliminating connections whose activity is divergent; modification of chromatin-binding proteins diminishes (making altered transcription more difficult).
Metabotrobic Receptors
Effects are slower, longer lasting, more diffuse, and more varied. Complicated. Uses a wide variety of NTMs. NT binds to the receptor and energy is used to detach a G-protein from the membrane; when the G-protein leaves, a channel opens, and a second messenger (ex. cAMP) is activated. The secondary messenger goes on to communicate with other areas in the cell. Concerned with enduring effects like taste, smell, and pain. Also arousal, attention, pleasure, and emotion. Basically all functions where timing is not important and arise slowly and last longer. Example: serotonin or dopamine receptors.
What kinds of activities increase neurogenesis?
Exercise Learning RUNNING
What is the difference between first and second pain?
First pain is caused by A delta fibers which at lower level stimuli causes a tingling sensation. When the stimulation is intense enough, a feeling of sharp pain is reported. Second pain is caused by the slower, unmyelinated C fibers (smaller diameter fiber axons) making its way up, making the second pain more dull and lasting. Figure 10.2!
What is the limbic system?
Forebrain circuit: Parahippocampal gyrus Olfactory bulbs Mammillary bodies (posterior hypo) Anterior nucleus of the thalamus (projects to cingulate gyrus) Cingulate gyrus (projects to hippocampus) Hippocampus (projects via the fornix to back of hypothalamus). INCLUDE: orbital and medial prefrontal cortex ventral parts of the basal ganglia mediodorsal nucleus of the thalamus amygdala IMPORTANT: not included in earlier accounts of limbic system and last two are important for emotion).
Label BRAIN Diagram
Frontal Lobe:Cognitive tasks;learning Central Sulcus: separates frontal and parietal lobes. Somatosensory cortex: muscle movement. Parietal: Learning, touch, motor info and processing. Occipital Lobe: Sight/vision Cerebellum:Balance/coordination Brainstem: contains medulla and pons (sleep and executive functions). Temporal Lobe: auditory info; language; memory Sylvian Fissure: Separates frontal and temporal lobes.
What are the two major inhibitory neurotransmitters in the central nervous system? What ion is associated with the effect of these receptors?
GABA Glycine Associate the inhibitory effects of GABA and glycine with Cl-.
What barriers prevent regeneration?
Glutamate overstimulation Apoptosis and Neuronal Death Glial Scarring Conditions not similar to those during development. Inflammatory cytokines.
Excitatory Postsynaptic Potential
Graded depolarization, temporary sodium rush into the cell. Ultimate effect is to make the postsynaptic cell more likely to fire an action potential
Inhibitory Postsynaptic Potential
Graded hyperpolarization, temporary potassium rush outside of the cell, flow of chloride ions into the cell. Ultimate effect is to make the postsynaptic cell less likely to fire an action potential.
Demyelinated axons?
If an axon is demyelinated then there is no action potential. This is because no voltage-gated ion channels exist in the axonal membrane underneath myelinated sections; therefore, when this myelin is removed, the action potential can't propagate.
What is the purpose of myelin? Explain how myelin speeds the conduction of the action potential?
Insulation: reduces ion leakage, allows APs to travel faster. Nodes of Ranvier Saltatory Conduction
Ionotropic Receptors
Ionotropic= ligand binds and an associated ion channel opens or closes, causing a Postsynaptic potential (EPSP/IPSP). Simple. Uses glutamate for most of its excitatory effects, uses GABA for most of its inhibitory effects. Concerned with quick effects, things like vision, hearing. Example is the NMDA receptors.
Photopic Vision
Is the vision of the eye in well lit conditions. Also allows for color vision and is mediated by cones.
What happens to the AP if you remove or significantly reduce the concentration of intracellular K+? Why?
K+ electrochemical equilibrium maintains the resting membrane potential. Without this the neuron would be in a constant activated state. In addition without the recovery phase no action potentials could act on that neuron.
What lines of evidence implicate the amygdala in fear conditioning?
LeDoux rat/foot shock experiments. Patient S.M. (damaged amygdala) Robogator NMDA antagonists
Reversal Potential
Membrane potential of a postsynaptic neuron at which the action of a given neurotransmitter causes no net flow. Reversal potential more positive than AP threshold = excitatory. Reversal potential more negative than AP threshold = inhibitory.
Meissner
Motion, rapidly adapting, upper most layer
Amygdala (fear conditioning) NMDA antagonists.
NMDA antagonists inserted into the amygdala can prevent fear conditioning; implicating that not only the importance of amygdala, but also that LTP may be a mechanism in which neurons associate a neutral stimulus with an aversive stimulus.
What are the three major types of ionotropic glutamate receptors, and why were they given these names? Why are the NMDA and AMPA receptors considered to be particularly important? What's unique about the NMDA receptor?
NMDA receptors, AMPA receptors, kainate receptors (named after the agonists that activate them). NMDA and AMPA receptors are located in central synapses. NMDA receptors allow entry of calcium and sodium and potassium.
What is neurogenesis?
Neurogenesis is the creation of nerves and glial cells from multipotent stem cells. ---> In the adult brain: stem cells produce TAC cells which are precursors to stem cells and go through cells cycles in the SGZ and SVZ. The TAC divides into neuroblasts or glioblasts.
Restoration of damaged central nerve cells.
New dendrites, axons, and synapses must grow from an existing cell body. Regeneration of CNS cells is rare because glial processes inhibit growth and glial scars form.
What is the purpose of sleep? What are the consequence of not getting enough sleep? What kind of evidence is there to suggest that sleep is important for cognition?
Niche Adaptation (large animals sleep longer; dinurnal) Restoration Energy Conservation (temp drops at night; metabolism slows) Memory Consolidation -Being sleep deprived for 24 hours results in similar behaviors as having a blood alcohol level of .08. -Similar brain activity during sleep deprivation as when asleep. Consequences of not getting enough sleep: changes in mood/emotion cognitive and memory deficits weight loss
Neurogenesis in the adult human brain?
Olfacotry bulb and hippocampus. SGZ and SVZ (has to take rostral migratory system). New cells are almost always interneurons. In humans there is no rostral migratory system so neurogenesis does not occur in olfactory bulbs.
New nerve cells in the adult CNS are generated reliably in the _______ and the _____.
Olfactory bulbs Hippocampus
Postsynaptic Potential
PSP; the potential change produced in a postsynaptic neuron by the binding of neurotransmitter released from a presynaptic neuron.
What lines of evidence support the proposal that declarative memory and procedural memory involve different brain mechanisms?
Patients with declarative amnesia are able to acquire skill/procedural memories without recollection of the training. H.M. was able to learn and remember the mirror-tracing task, even though he had severe anterograde amnesia.
Is REM sleep more like deep sleep or wakefulness?
REM sleep is more like wakefulness! Certain physiological changes occur during REM sleep that look similar to wakefulness that do not occur in other NREM stages: increased heart rate, increased respiration, increased metabolic rate, constricted pupils, and penile erection. EEGs of people who are awake and those who are in REM stage match (alpha/beta waves). REM sleep waves are characteristically similar to EEG waves when awake. They both show high frequency, low amplitude beta waves. They are also asynchronized.
Le Doux Rat Experiments
Rats and footshocks. Like classical conditioning, an aversive unconditioned stimulus (foot shock) is paired with a conditioned stimulus (bell ringing). Rats with intact amygdalas will show autonomic and behavioral responses of fear when just exposed to the conditioned stimulus. Rats with lesions to their amygdala do not show this.
What is the difference between a receptor potential, a synaptic potential, and an action potential?
Receptor potentials are due to activation of sensory neurons by external stimuli. These neurons respond with a receptor potential that changes the resting potential for a fraction of a second. Graded potential; amplitude is proportional to strength of stimuli. Synaptic potential is communication at synaptic contacts that allows neuron to neuron contact. Action potentials: neurons generate special type of electrical signal that travels along their axons. APs allow for long range transmission of information within the nervous system that allows for info to reach target organs/body parts. APs are all or nothing and amplitude is not proportional to the strength of stimulation.
Peripheral nerve restoration?
Regrowth of axons, either from nerve cells in peripheral ganglion or from CNS cells whose peripheral projections of axons are severed, it is called peripheral nerve regeneration. -->Most effective -->Schwann cells provide many of the molecules needed (adhesion molecules, neurotrophis, and growth promoting molecules. -->The nerve itself will start to express growth-related genes. -->There is some imprecision of the reinnervation of specific targets (Henry Head's slowness/imprecision of recovery of his fine motor skills and sensory function).
Draw a typical action potential, label the axes (in mV), and for each phase of the action potential, describe the key events that underlie each phase. (rising phase, overshoot phase, falling phase, undershoot phase).
Resting membrane potential K+ equilibrium. Stimulus depolarizes cell past threshold; Na+ rushes in. Reaches action potential peak at Na+ electrochemical equilibrium. Refractory period; cannot have another action potential. Cell begins to hyperpolarize K+ moves into cell. Strong stimulus could cause another action potential. Undershoot phase too much K+ enters cell. Returns back to resting potential.
The mode of action potential propagation along myelinated axons is called _______ conduction.
Saltatory action potential
Ruffini
Skin stretch, slowly adapting, dermal area.
In the adult mammalian hippocampus and olfactory bulb, new neurons are GENERATED from the ______ or the _______.
Subventricular Zone (SVZ) Subgranular Zone (SGZ)
What has patient H.M. taught us about human memory?
Surgeon took out his hippocampus and surrounding brain regions in an attempt to cure his epilepsy. He suffered massive anterograde amnesia and some retrograde amnesia. He still had personality, intellect, and language abilities. STM and working memory were still intact, bust as soon as he was distracted, memory was gone. Severe impairment in episodic memory, but still maintained procedural memory. Taught us that hippocampus and surrounding areas are necessary for LTM.
Nernst Equation
The Nernst equation predicts the equilibrium potential for a specific ion using the relative concentrations of the ion between the outside and inside of the membrane.
What prevents action potentials from turning around and going back up the axon?
The absolute refractory period. It takes a bit of time for the sodium channels to reactivate, so ions are more likely to affect channels ahead rather than behind.
Beyond fear conditioning, what does the amygdala do, generally?
The amygdala is involved in satiation, so anything we find strange or satisfying stimulates it. It is also involved in some way in almost every emotion. Also involved in recognizing things that are strange. Also involved in rewards.
What is the functional difference between indirect and direct pathways of the basal ganglia in terms of regulating movement? Generally, how is this accomplished?
The direct pathway, uses D1 receptors, and promotes appraoch movement much like reward would. The indirect pathway, uses D2 receptors, and inhibits approach movement, much like punisment would.
What is the equilibrium potential?
The equilibrium potential is the membrane potential at which there is no net ion flow. Ions still move across the membrane, but the rates of influx and efflux are the same, so the concentrations of ions on either side remain constant. This is due to both the electrical and chemical gradients.
What are the main input areas of the basal ganglia?
The largest source of neural input is the striatum (caudate and putamen). Nearly all regions of the cortex project here.
SGZ and SVZ
The neuroblasts or glioblasts from SGZ go from basal granular layers of hippocampus to higher levels. Those in the SVZ go to the olfactory bulb via the rostral migratory system.
Are there more rods or cones in the retina? In the fovea? What accounts for the fact that rods do not contribute to vision in daylight?
There are more rods in the retina than cones. Cones are more dense in the fovea and rods are more around the periphery. Rods do not contribute to vision in daylight because, at a certain level of illumination, membrane potentials in rod cells reach a saturation point because every channel in an individual rod is closed.
What will happen to the AP if you remove or significantly reduce the concentration of extracellular Na+? Why?
There would not be a large influx of Na+ to induce a current. Cell would have a hard time reaching threshold. If it did invoke an action potential the amplitude would be lower.
What are mechanoreceptors? Name 4 mechanoreceptors and what they respond to.
These are receptor cells which encapsulate afferent fibers and tune them to particular features of somatic stimulation. Afferents which have encapsulated endings have lower thresholds for action potential generation and are thus more sensitive to sensory stimulation (than free nerve endings). The receptors below all have the ABeta afferent axon type: Meissner - detect motion, rapidly adapting, upper most layer Merkel - detect edges, slowly adapting , epidermis Ruffini - skin stretch, slowly adapting , dermal area Pacinian - detect vibrations, slow rapidly adapting, subcutaneous
Functional reorganization
Uses existing neurons and circuits to regain function instead of new neurons or fixing damaged ones. Has to do with brain plasticity.
What are the advantages of having both rods and cones, rather than just one type of photoreceptor?
With both rods and cones we are able to see things in the light as well as dark. Even though we do not have strong acuity in the dark we still have some vision.
