biopsychology quizzes
In the experiments conducted by Hodgkin and Huxley, the early current disappeared if the membrane was clamped at _______ mV.
+52
Which observation was not observed in Hodgkin and colleagues' voltage-clamp study of squid action potentials?
A sustained outward current as a result of hyperpolarization
Which treatment would prevent the release of neurotransmitter from the presynaptic terminal?
A toxin that cleaves synaptobrevin
Which statement is a common, defining feature of membrane-bound active ion transporters?
All are able to move at least one ion against its concentration gradient
Based on the distribution of endocannabinoid receptors in the brain, it can be surmised that Δ9-tetrahydrocannabinol likely has an influence on
All of the above
Based on the observations made by Hodgkin and Huxley, one can expect ion channels to
All of the above
Cognitive neuroscience is concerned with
All of the above
Glutamate is
All of the above
In addition to their traditional motor program selection and implementation functions, the basal ganglia are also thought to be involved in
All of the above
In the operation of sodium-potassium ATPase,
All of the above
Tyrosine hydroxylase is a substrate for which protein kinase(s)?
All of the above
Which characteristic is an accepted criterion for classifying a molecule as a neurotransmitter?
All of the above
Which brain region is deactivated when a mother views a picture of her child?
Amygdala
Which statement best describes the action potential?
An action potential occurs when the cell's membrane potential reaches threshold
Which of the following is a characteristic of Purkinje cells that allows for the high level of convergence and divergence from the granule cells?
An elaborate dendritic tree that extends perpendicularly to the parallel fibers
Which of the following is a major function of the cerebellum?
Analyze errors between intended motor output and actual motor output
Which amygdaloid nucleus is correctly paired with its primary connections?
Central nucleus—hypothalamus
A scientist creates a D1 receptor knockout mouse. How would this effect the functioning of the basal ganglia?
Cerebral cortex input to spiny neurons would not be enhanced
Which of the following is the first step in the nuclear signaling process?
Chromatin decondensation
When a GABAA ionotropic receptor is stimulated by GABA in a developing neuron, which ions flow through its channel, and what effect does this have on the postsynaptic cell?
Cl-, which depolarizes the postsynaptic cell
Which protein plays a key role in endocytosis?
Clathrin
Which synapses have the strongest excitatory connection?
Climbing fibers synapsing on Purkinje cells
Which drug of abuse exerts its effect by interacting directly with dopamine synapses in the nucleus accumbens?
Cocaine
What would occur if the ATPase pumps in a neuron stopped functioning?
Concentration gradients would not be maintained across the membrane
Which structure can be found exclusively at an electrical synapse?
Connexon
Aromatase is responsible for which action?
Converts testosterone to estradiol
Which second messenger plays an important role in sensory transduction processes?
Cyclic nucleotide
Which technique first produced unequivocal support for the neuron doctrine of the nervous system (as opposed to the reticular theory)?
Electron microscopy of nervous tissue
Which of the following is not a class of opioid peptides?
Endocannabinoids
Which substance is not involved in masculinization of the genitalia and nervous system?
Epinephrine
Treating a male zebra finch during development with which drug would lead to a female-like neural song circuit?
Estrogen receptor antagonist
Which experimental model did Hodgkin and Katz use in their studies of the resting membrane potential?
Living squid neuron
The cell bodies of neurons that release norepinephrine project from which structure?
Locus coeruleus
Which statement about voltage-gated ion channels is true?
Na+ and K+ channels can work independently of one another
Which statement describes one of the features of Hodgkin and Huxley's mathematical model?
The action potential can be reconstructed based entirely on the time course and amplitudes of the ionic conductances
Refer to the figure. Which of the following is the key event at a membrane potential of -26 mV?
The late outward current increases in magnitude
Which statement about sexual dimorphism of the spinal nucleus of the bulbocavernosus (SNB) in rats is false?
The male perineal muscles have androgen receptors, but the female muscles do not.
Which current corresponds to a flow of Na+ in response to a depolarizing stimulus in a giant axon of a squid?
Transient inward current
Which gene regulation strategy underlies the action of glucocorticoid hormones?
Translocation of the receptor into the nucleus to bind to DNA
Which function is a characteristic primarily of neurons only, and not glia?
Transmits action potentials
What effect would testosterone treatment during development have on the size of the adult AVPV?
Treated females would have decreased cell numbers compared to control females due to an increase in apoptosis
What effect would testosterone treatment during development have on the size of the adult SDN-POA?
Treated females would have increased cell numbers compared to control females due to inhibition of apoptosis
Why is the white matter lighter than the gray matter?
White matter is richer in myelin, which reflects more light than gray matter
Under which circumstances is the Goldman equation equivalent to the Nernst equation?
When a membrane is permeable to only one ion
Which signaling pathway does not directly involve calcium?
cGMP
The axons transmitting cortical signals to the basal ganglia
carry information whose nature is poorly understood
Increased activity from the _______ to the subthalamic nucleus increases the _______ input to the VA/VL complex of the thalamus.
cerebral cortex; inhibitory
The acetylcholine receptor at the neuromuscular junction would best be described as a(n)
channel-linked receptor
The primary motor cortex processes information for muscles on the _______ side of the body; the cerebellum processes information for muscles on _______ side(s) of the body.
contralateral; the ipsilateral
One of the outputs of the basal ganglia, the substantia nigra pars reticulata, is most similar in its function to the
globus pallidus
There is a high degree of convergence from the medium spiny neurons to the neurons of the _______ and _______.
globus pallidus; substantia nigra pars reticulata
The TRP ion channel family includes channels responsive to
heat and cold
Injury to the fornix would prevent neural communication from the _______ to the _______.
hippocampus; hypothalamus
Neuroethology is the field devoted to studying complex behavior
in the native environment
Functional neuroimaging studies (Drevets and Raichle) of subjects with unipolar depression have shown
increased blood flow in the amygdala and specific areas in the prefrontal cortex
In deep brain stimulation for the treatment of Parkinson's disease,
stimulation parameters such as pulse width, current amplitudes, and pattern are determined by trial and error
In Parkinson's disease, dopaminergic input from the _______ decreases.
substantia nigra pars compacta
The external segment of the globus pallidus projects to the internal segment and the _______ in the _______ pathway.
subthalamic nucleus; indirect
Substania nigra pars reticulata axons project to _______; the globus pallidus axons do not project to this region.
superior colliculus
The substantia nigra pars reticulata projects to the
superior colliculus
What is the functional result of long-term depression in the cerebellum?
A stronger neuronal response of the deep excitatory loop
How many connexin subunits form one complete synaptic channel?
12
Listed below are the enzymes needed to synthesize epinephrine (adrenaline).1. Dopamine-β hydroxylase2. Tyrosine hydroxylase3. Phenylethanolamine-N-methyl transferase4. DOPA decarboxylaseWhich of the following is the correct sequence of enzyme actions in the synthesis of epinephrine?
2; 4; 1; 3
Listed below are the individual events that make up chemical synaptic transmission.1. Diffusion of transmitter across the synaptic cleft2. Depolarization of the presynaptic terminal3. Vesicle fusion with plasma membrane4. Opening of voltage-gated ion channels5. Activation of presynaptic, calcium-sensitive proteinsWhich sequence represents the correct ordering of these events?
2; 4; 5; 3; 1
Listed below are the events that make up NGF-mediated growth of sensory neurons.1. TrkA receptor self-phosphorylation2. Translocation of activated kinases to the nucleus3. NGF-induced dimerization of membrane receptors4. TrkA induction of the ras signaling pathwayWhich is the correct sequence of these events?
3; 1; 4; 2
Listed below are the events that occur during basal ganglia functioning.1. Disinhibition of ventral anterior and ventral lateral thalamic nuclei2. Inhibition of globus pallidus3. Excitation of caudate and putamenWhich of the following is the correct sequence of these events?
3; 2; 1
At which time interval between pre- and postsynaptic activity would STDP occur?
40 ms, regardless of whether pre- or postsynaptic activity occurs first
Refer to the figure. A researcher conducts a voltage clamp experiment on a giant squid axon. She clamps a typical neuron at 0mV. Which graph represents the current changes she will observe.
A
You are examining long-term potentiation in two groups of hippocampal neurons: control and treated. You induce lasting LTP in the control cells after repetitive high-frequency stimulation. In the treated cell, however, the potentiation begins to decrease after 2 hours. What treatment was given?
A drug that inhibits protein synthesis
Which statement describes a possible outcome for a neurotransmitter after release into the synaptic cleft?
Activation of G-protein-coupled receptor on postsynaptic cell
In a signal transduction cascade using G-proteins and cAMP, which is not a signal amplification step?
Activation of adenylyl cyclase molecules by G-proteins
Work done by _______ elucidated changes in membrane permeability that underlie an action potential.
Alan Hodgkin and Andrew Huxley
Which property of LTP underlies Pavlovian conditioning?
Associativity
Refer to the figure. Which region is responsible for communication between the hippocampus and the hypothalamus?
B
Which structure does not provide input to the amygdala?
Basal ganglia
Which feature of an electrical synapse allows synchronizing the electrical activity of multiple neurons?
Bidirectional transmission of electrical signals
The basal ganglia's ability to evoke one specific movement pattern out of an almost endless variety of possible movement patterns is best ascribed to which neural coding strategy?
Center-surround style decision making
What causes synaptic facilitation?
Buildup of Ca2+ in the presynaptic terminal
By which proposed molecular mechanism does Ca2+ promote fusion of synaptic vesicles?
By binding to and inducing changes in synaptotagmin that cause the plasma membrane to curve, facilitating fusion
Which protein facilitates the late phase of LTP?
CREB
Which statement about the mechanisms underlying hippocampal LTP induction is false?
Calcium decreases a resting leak current of sodium so that the postsynaptic cell is closer to threshold and therefore fires more easily
Refer to the figure. Which technique is illustrated in the figure, and what can it be used to measure?
Cell-attached patch clamp; measures the current that flows through a single ion channel
From which part of the nervous system do cells that innervate neuromuscular junctions originate?
Central nervous system (CNS)
A researcher injects a GABA antagonist into the globus pallidus and then stimulates the striatum. What are the expected changes in the downstream response?
Decreased activation of the globus pallidus and decreased excitation of the motor cortex
Which symptoms, together, indicate clinical depression?
Deep sadness, disordered sleep and eating, and poor concentration
Which of the following was observed in studies measuring the efflux of radioactive sodium from the squid giant axon?
Dependence of efflux upon the presence of ATP
A patient can smile when asked to by her doctor, but when she is told a funny joke, she is unable to smile. Where does the patient most likely have damage?
Descending projections from the hypothalamus
Which of Camillo Golgi's contributions enabled Santiago Ramón y Cajal to make observations that suggested that nerve cells are discrete entities?
Development of a staining method based on impregnation with silver salts
What is the direct role of the SRY gene?
Development of the testes
A scientist wishes to develop a new drug that prevents synaptic communication via neuropeptides but not small molecule neurotransmitters. Which mechanism would be a good target for his drug?
Disruption of axonal transport
Which neurotransmitter has been identified as seminally involved in an organism's reward system and is often altered by drugs of abuse?
Dopamine
Which would be the most likely consequence of a mutation that renders DOPA decarboxylase inactive?
Dopamine would not be produced
Which Drosophila melanogaster genotype is associated with the worst performance in an olfactory learning task?
Dunce, rutabaga double mutant
Damage to the midline of the cerebellar cortex would lead to dysfunction in what type of motor output?
Eye movement
What is the source of the quanta that make up the EPP?
Fusion of individual synaptic vesicles with the plasma membrane
The transmitter for the medium spiny neurons of the striatum is
GABA
Which receptor type can be modulated by both barbiturates and benzodiazepines?
GABAA
Refer to the figure. Which region of the basal ganglia is indicated by the asterisk?
Globus pallidus
Output from the basal ganglia projects from which structures?
Globus pallidus and substantia nigra pars reticulata
Subthalamic nucleus neurons that project to the internal segment of the globus pallidus release which transmitter?
Glutamate
What is the main excitatory neurotransmitter in the adult brain?
Glutamate
The presence of which compound or protein in a cell makes it quite likely that the cell is a GABAergic neuron?
Glutamic acid decarboxylase
Damage to the subthalamic nucleus results in which condition?
Hemiballismus
A female rodent is treated with dihydrotestosterone (DHT) during development. DHT acts on androgen receptors and is not converted to estradiol. Which outcome would you expect to see?
Her SDN-POA would be the same size as control females
A male student participated in a genetic testing experiment at his university. He discovered that he is genetically XX. How could this be?
His second X chromosome was completely inactivated, leading to the default male phenotype.
Which of the following is not a catecholamine?
Histamine
Which symptom is not characteristic of PTSD?
Hyperactivity
In the rat, estrogen receptors are densely distributed in which brain region?
Hypothalamus
Which of the following provides an example of a second messenger producing another second messenger?
IP3 binds to its receptor, enabling the release of Ca2+ from the cytosol
Which statement about LTP is false?
If one synapse (A) is very strongly stimulated (sufficient to cause LTP), and a nearby synapse (B) on the same cell is weakly stimulated a few seconds later, then the second synapse (B) will also show LTP
Which statement best describes the electrical properties of nerve cells?
In comparison to copper wires, they are relatively poor conductors of electricity
Which evidence suggests that dopaminergic input to the striatum may contribute to reward-related modulation of behavior?
In monkeys, latencies of saccades toward a target are shorter when associated with a larger reward
Which statement about the ionic permeability of cell membranes is true?
In resting nerve cells, the membrane is quite permeable to potassium.
What is the mechanism of LTP expression?
Increase in the number of postsynaptic AMPA receptors
Cholera toxin locks the Gs subunit into an active state, in that GTP is bound and cannot be hydrolyzed back to GDP to turn off the subunit. What effect will cholera toxin have in the cell?
Increased cyclic AMP levels will lead to increased protein kinase A activation
Damage to which structure would lead to dysfunction in cerebellar learning and memory functions?
Inferior olive
Selectively inhibiting gap junction channels would directly alter the activity in which region?
Inferior olive
Which experimental manipulation would prevent the formation of a partner preference in a female vole?
Injection of a D2 receptor antagonist in the nucleus accumbens
Which of the following is not an established role for glial cells?
Integrating information to assist neural computation
Damage to which pathway would affect voluntary movement of the limbs?
Interposed nuclei output to the thalamus via the superior cerebellar peduncle
Which statement regarding metabotropic and ionotropic receptors is true?
Ionotropic receptors have immediate effects; metabotropic receptors produce long-term effectsWhich statement about EPSPs in the central nervous system is true?
Which ion is transported down its concentration gradient by transporters?
Na+
Which role does calmodulin play in the intracellular cascade triggered by Ca2+?
It binds to its downstream targets when activated by Ca2+
Which statement about a nicotinic acetylcholine receptor at the neuromuscular junction is accurate?
It has two binding sites, and binding of two molecules of acetylcholine, one to each site, is required to activate the receptor
What role does Bax play in the cell during development?
It increases apoptosis
Which statement about a center-surround receptive field is false?
It is found only in primary sensory cortex
What is the role of the red nucleus?
It provides cerebellar output feedback to the inferior olive
Which statement about multiple sclerosis (MS) is false?
It was recently proven that all cases of MS are due to persistent infection by a tropical parasite
In a two-compartment model of a cell with a K+- and Ca2+-permeable membrane and a 10-fold excess of K+ in the inside compartment, how would the membrane potential change if all K+ ions were replaced by Ca2+ ions?
It would be reduced by half
How would application of an intracellular Ca2+ chelator affect the function of a synapse?
It would eliminate the postsynaptic potential and Ca2+-dependent vesicle fusion
If an aromatase inhibitor was given during perinatal development, what effect would that have on the animal?
It would prevent the masculinization by estrogen (mediated via estrogen receptors)
Which statement about kindling is true?
Its effect is long-lasting
Refer to the figure. Glutamate sensitivity (the amplitude of response to the application of glutamate) is color coded. The micrograph on the right was taken 120 minutes after the micrograph on the left. Which form of plasticity is shown in the figure?
LTP
Which stimulus is most likely to evoke an action potential?
Large depolarizing current pulse
When the right cerebellum is damaged, which cortical region loses input (either directly or indirectly)?
Left motor cortex
Which kinase is activated by the phosphorylation of its activation loop?
MAPK
Damage to which structure would prevent communication from the cingulate cortex to the anterior nucleus of the thalamus?
Mammillary body
Which structure is responsible for input only to the cerebellum?
Middle cerebellar peduncle
In what way does the function of monomeric G-proteins differ from that of heterotrimeric G-proteins?
Monomeric G-protein activation is controlled by guanine nucleotide exchange factors, heterotrimeric G-protein activation is not
What cell type does not have direct contact with Purkinje cells?
Mossy fibers
Which statement accurately describes the expression of genes in the nervous system?
Most of the genes in the human genome are expressed in the CNS
Why does the function of GABAA receptors vary among neuronal types?
Multiple types of GABAA receptor subunits exist
Which statement about myelination is false?
Myelin serves to sharply increase the time constant of the axon
Refer to the figure. What does the figure depict?
Na+/K+/Cl- co-transporter
Which regions of the cerebral cortex project directly to the striatum?
Nearly all regions of the cerebral cortex
What evidence suggests that medium spiny neurons are associated with a decision to move?
Neurons in the putamen and caudate discharge seconds before the initiation of movement
Refer to the figure. Which cell type forms the structure labeled C?
Oligodendrocytes in the central nervous system
In which way do potassium channels in the squid giant axon differ from sodium channels?
Once the potassium channels open in response to a voltage step command, they tend to remain open
Which neurotransmitters play an important role in the feeling of being in love?
Oxytocin and vasopressin
How does membrane permeability to K+ (PK) and Na+ (PNa) change during an action potential?
PK exceeds PNa at rest; PNa temporarily increases during the action potential
A hallmark of Alzheimer's disease is excessive phosphorylation of tau protein, which is thought to be due to defects in
PP2A
Which molecule is an effector directly downstream of an activated G-protein?
Phospholipase C
Which mechanism contributes to the long-term enhancement of the gill withdrawal reflex in Aplysia but is not involved in the short-term enhancement of the reflex?
Phosphorylation of CREB
Fibers from which structure(s) cross the midline prior to synapsing in the cerebellum?
Pontine nuclei
Which type of short-term synaptic plasticity lasts the longest?
Post-tetanic potentiation
Which synaptic connection would be most affected by the presence of a GABA antagonist in the cerebellum?
Purkinje cell input onto deep cerebellar nuclear cells
Which type of cell provides the only output from the cerebellar cortex?
Purkinje cells
Which nuclei comprise the striatum?
Putamen and caudate
Refer to the figure. A cat undergoes surgery to remove the brain region shown in blue in the figure. What type of behavior would you expect to see after the cat awakes from anesthesia?
Rageful
Which statement regarding Huntington's disease is false?
Recent genetic findings have led to successful gene therapy treatment and a cure
Which type(s) of electrical signals occur(s) within the neural circuit for a spinal reflex?
Receptor potential, synaptic potential, and action potential
Which treatment was shown to eliminate the early inward current in squid giant axons?
Removal of external sodium
Neurons in the CNS that release epinephrine regulate which function?
Respiration
Which state of the plasma membrane does not occur during an action potential?
Resting phase
A doctor taps the right knee in an individual who was in a car accident and has sustained damage to the right dorsal root of the lower spinal cord. Which motor response would you expect?
Right leg remains motionless
During which phase of an action potential does membrane permeability to Na+exceed membrane permeability to K+?
Rising and overshoot phases
Which cell produces myelin in the nerves of the peripheral nervous system?
Schwann cell
Refer to the figure. The figure depicts a normal action potential (left) and an action potential altered by application of a toxin (right).What are the source and mechanism of action of the toxin used?
Scorpion; slows the inactivation of Na+ channels
Which substance is a neurotransmitter that stimulates metabotropic 5-HT receptors, which have been implicated in circadian rhythm, satiety, motor behavior, and emotional state regulation?
Serotonin
A researcher is trying to study synaptic transmission in a glutamatergic hippocampal neuron. She is tasked with measuring calcium flow in the postsynaptic hippocampal neuron after either low or high intensity stimulation to the presynaptic neuron. During the experiment, she measures calcium influx after both low and high stimulation. Which statement best describes the error she made?
She forgot to add magnesium to the extracellular solution
Which statement about ionic distributions in nerve cells is true?
Sodium is higher outside cells than inside cells
Which cerebellar output is correctly paired with its function?
Spinocerebellum—motor execution
Schizophrenia and _______ are associated with mutations in MAOA and COMT genes
bipolar disorder
Excitation of the motor cortex is associated with excitation in which other brain region?
Striatum
Where are medium spiny neurons located?
Striatum
Dopaminergic neurons that synapse on medium spiny neurons originate from which brain region?
Substantia nigra pars compacta
Which region is one of the most common targets for deep brain stimulation?
Subthalamic nucleus
Which observation would demonstrate the spike timing-dependent plasticity of synapses?
Switching the relative timing of action potential and EPSP by as little as 20 ms can switch the response from LTD to LTP, or vice-versa
Which chemical signaling process is the slowest?
Synthesis of proteins after CREB activation
Which structure relays input between the cortex and the cerebellum?
Thalamus
What effect would a mutation in the estrogen receptor gene have on the development of the AVPV?
The AVPV in knockout males would be larger than control males
A rodent animal model has a mutation in the androgen receptor (AR), making it dysfunctional. If you looked at the SND-POA of adults of this mutant AR animal model, what would you expect to see?
The SDN-POA would be the same size in mutant males as in control males
Refer to the figure. What would happen if the membrane became permeable to the Y+ ions?
The Y+ ions would move into the top chamber, down their concentration gradient
Which statement correctly differentiates between the passive and active current in a myelinated axon?
The active current flows only in the nodes of Ranvier, unlike the passive current
Janet is examining slides containing male vole brain slices. She determines the vole she is looking at lived a monogamous, pair-bonded lifestyle. What did she see on the slides that led her to that conclusion?
The animal had a high density of vasopressin receptors in the ventral pallidum
Which evidence supports the assertion that the macroscopic Na+ current is the sum of many microscopic Na+ currents?
The averaged collective response of single channels resembles the time course of the macroscopic current
A female mouse is treated during development with testosterone. What effect would this have on the development of the spinal nucleus of the bulbocavernosus (SNB) system?
The bulbocavernosus muscle would be present, and the number of motor neurons present would be more than controls
A neuron has received enough stimulation to fire an action potential; it also has been treated with TEA, a K+ channel blocker. Which outcome is possible?
The cell will initially depolarize, but repolarization will take much longer because it relies only on ion pumps
Which statement on the rising or overshoot phase of the action potential is true?
The degree of depolarization is limited in part by the inactivation time course for the sodium current
Refer to the figure. Which of the following is the key event at the membrane potential of 65 mV?
The early and late currents flow outward
A dull probe stimulates a Pacinian corpuscle. An electrode is placed midway down the axon, and action potentials are recorded. After one second, the probe is pushed with greater force. What change will occur in the recording?
The frequency of action potentials will increase
A transgenic mouse animal model is created that expresses both the Cre recombinase gene, under control of a promoter for a gene expressed only in muscle fibers, and an androgen receptor with loxP sites around exon 2. How will expression of the androgen receptor protein be altered in the transgenic mouse?
The mouse will not express androgen receptor in muscle fibers
Which is not a feature of glutamate signaling systems?
The passage of large amounts of magnesium and calcium by NMDA receptors
A lab rat undergoes fear conditioning training in which a soft tone is paired with an electric shock. However, after repeated tests, the rat does not show freezing behavior in response to the tone alone. What could explain this result?
The rat had received an injection of an NMDA receptor antagonist in its amygdala
Which statement regarding refractory periods is true?
The refractory period ends when the sodium channels are no longer inactivated
Which statement about lateralization of emotional processing is true?
The right hemisphere is involved in the perception and expression of emotion
Which process(es) underlie(s) the refractory period?
The slow time course of turning off K+ conductance activation and the persistence of Na+ conductance inactivation
Refer to the figure. The function of which synapse is altered during sensitization?
The synapse between the sensory neuron of the siphon and the motor neuron
Which statement does not describe one of the findings of Bard and Hess's studies of emotion?
The visceral and somatic motor aspects of emotion are mediated by a common brain circuit
Which statement about EPSPs in the central nervous system is true?
Their effect in the central nervous system can be nullified by IPSPs
A researcher studying synaptic transmission in a glutamatergic hippocampal neuron attempts to measure calcium flow in the postsynaptic hippocampal neuron after either low or high intensity stimulation to the presynaptic neuron. Predict the results of the different stimulations.
There will be an influx calcium after high intensity stimulation
In an experiment on an animal model in which the synapsin gene is knocked out, you measure the density of synaptic vesicles in the presynaptic terminal within the active zone and outside the active zone in both knockout and control animals. Given what you know about the function of synapsin, what would you expect to find?
There will be fewer vesicles in the reserve pool in knockout animals than in controls
Which statement best describes most neurons?
They are polarized
What role do climbing fibers play in the cerebellum?
They lead to long-term potentiation, which increases the strength of parallel fiber synapses
Which statement about active ion transporters is true?
They move certain ions against the concentration gradient
Which statement about astrocytes is true?
They play a role in the formation of the blood-brain barrier
What do microscopic and macroscopic Na+ currents have in common?
They represent a flow of many ions
Which statement about silent synapses is true?
They transmit information at a resting membrane potential
Which statement about dendritic spines is false?
They usually contain just three proteins: NMDA receptors, mGluR receptors, and CaM kinase II
In a two-compartment model of a cell with a K+-permeable membrane and a 10-fold excess K+ in the inside compartment, the membrane potential is experimentally made more negative than the K+ equilibrium potential. How would K+ ions flow across the membrane?
They would flow from the outside compartment to the inside compartment
Which region sends dopaminergic inputs to the nucleus accumbens?
Ventral tegmental area
Which cerebellar structure is correctly paired with its function?
Vestibulocerebellum—posture
To date, which observation is not part of the experimental evidence favoring the vesicular release hypothesis of neurotransmission?
Visualization of acetylcholine molecules diffusing out of the neck of the membrane-fused vesicle
Which of the following does not contribute to maintaining low levels of calcium in resting nerve cells?
Voltage-gated calcium channels
The proteins that establish ionic gradients are called
active transporters
The amplitude of the action potential of a given neuron is
always the same
Ventral divisions of the basal ganglia receive excitatory inputs from the
anterior cingulate
An inability to express emotion through modulation of speech is called
aprosodia
Structures that form the voltage sensors of K+ channels
are embedded in the cell membrane
In the mature central nervous system, glial stem cells with the properties of astrocytes can give rise to
astrocytes, oligodendrocytes, and neurons
In associative learning studies in monkeys, subjects that had been successfully conditioned to a stimulus showed _______ dopaminergic neural activity in the ventral tegmental area _______.
decreased; when the predicted reward was withheld
An action potential occurs if current injected into a neuron _______ the neuron to reach _______ potential.
depolarizes; threshold
Firing an action potential in an axon initially causes a 10-mV depolarization (EPSP) in a postsynaptic neuron, but after applying a certain stimulus to the axon, firing it causes an 8-mV depolarization after each action potential. This phenomenon is called synaptic
depression
The basal ganglia are thought to elicit movement via
disinhibition of thalamic neurons (VA/VL)
Presynaptic and postsynaptic neurons that form _______ synapses are connected via _______.
electrical; gap junctions
The capability of a nerve terminal to rapidly and dramatically produce very large changes in calcium levels is most dependent on the
enormous gradient of calcium across the membrane
LTP represents a lasting increase in the size of EPSP
following a high-frequency train of stimuli
SNARE proteins participate in vesicle exocytosis by
forming a protein complex that pulls the vesicle membrane against the plasma membrane
Nodes of Ranvier represent
gaps in myelin wrapping
Efferent neurons from the globus pallidus that influence the activity of the motor areas of the cortex arise from the _______ segment and relay in the _______ before reaching the cortex.
internal; VA/VL thalamic nuclei
The effector molecule at the synapse of an intercellular signal transduction process is a(n)
ion channel
Postsynaptic currents produced by AMPA glutamate receptors are _______ than those produced by other ionotropic glutamate receptors.
larger
The voltage clamp method controls the _______ at any desired level.
membrane potential
D1 and D2 receptors are _______, with D1 receptors _______ cAMP and D2 receptors _______ cAMP.
metabotropic; increasing; decreasing
In a two-compartment model of a cell with a K+-permeable membrane, at K+ equilibrium potential, there is _______ flux of K+ ions.
no net
Refer to the figure. In the phase labeled B, the voltage-gated sodium channels are ________ and the voltage-gated potassium channels are ________.
open; closed
The _______ most directly affects the rate of information processing within the central nervous system.
propagation speed of action potentials
The part of a synapse to which the contents of synaptic vesicles bind is called the
receptor
The current flowing through individual ion channels
reflects the passage of thousands of ions per millisecond
Sexually dimorphic somatic structures and neural brain circuits are most prominently involved in
reproductive and parenting behaviors
Focal application of a GABA receptor agonist within the substantia nigra pars reticulata would most likely
result in involuntary saccadic eye movements
A surprising result that emerged from the molecular and genetic analysis of ion channels was the
sheer number of different ion channels
At -10 mV, end plate current is _______ in amplitude and directed _______.
small; inward
The technique that first revealed the tremendous diversity of neuronal cell types, by revealing different cell bodies along with their processes, is
the Golgi technique (stain)
The key aspect of receptor-gating in the associative induction of hippocampal LTP is that
the NMDA receptor acts as a molecular coincidence detector
When current is injected into an axon,
the current will decay exponentially with increasing distance from the injection site (if no action potential is present)
The squid giant axon is useful in neuronal studies because
the cytoplasm in the axon can be extruded, thus allowing studies of its composition
The most mysterious aspect of emotional experience is
the highly subjective "feelings" that attend many emotional states
Unconventional neurotransmitters
transmit signals between neurons
A K+ inward rectifier channel has
two transmembrane domains and a pore loop, but no voltage sensor
The in situ hybridization method is based on
using nucleic acid probes to detect mRNAs that encode specific genes
The most important factor determining whether a receptor-operated ion channel is inhibitory or excitatory is
whether the permeant ion's reversal potential is positive or negative to threshold
Which neurons do not directly synapse on the striatum?
α motor neurons
