Quiz
BioPsych Final
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Perguntas do quiz (160)
1Which of the following statements about neural and glial cells is false?
- AMitochondria are concentrated at presynaptic terminals.
- BThe endoplasmic reticulum is concentrated in axons.
- CExocytosis and endocytosis are important for synaptic communication.
- DGlial cells rapidly transmit long-range electrical signals.
- EBoth b and d
2Which technique first produced unequivocal support for the neuron doctrine of the nervous system (as opposed to the reticular theory)?
- AGolgi stain (light microscopy)
- BExtracellular electrical recordings
- CEEG (electroencephalogram)
- D
Acetylcholinesterase staining - E Electron microscopy of nervous tissue
3Which of the following is an advantage that intracellular recordings have over extracellular recordings?
- AThey are technically easier to obtain.
- BThey can be used in many more parts of the nervous system.
- CThey can record synaptic and receptor potentials.
- DThey can record from many neurons at once.
- EAll of the Above
- AThey are technically easier to obtain.
4Which of the following is not part of the brain?
- ADiencephalon
- BCerebellum
- CCerebral Hemispheres
- DSpinal Cord
- EBrainstem
5Antibody staining is used to
- Aidentify neurons expressing specific genes.
- Bvisualize the distribution of specific proteins in the nervous system.
- Ctrace anterograde pathways.
- Dtrace retrograde pathways
- Ereveal structural changes associated with experimental lesions
- Aidentify neurons expressing specific genes.
6Which of the following is not an established role for glial cells?
- A Integrating information to assist neural computation
- BMaintaining the ionic milieu surrounding nerve cells
- CHastening the propagation of neural impulses
- DAssisting synaptic transmission via neurotransmitter uptake
- EProviding scaffolds that assist neural development
7Which of the following is a feature that distinguishes the four model organisms from other animals that have been intensively studied by neuroscientists?
- AEase of genetic analysis and manipulation
- BNervous systems of substantial complexity
- CAn extensive and interesting behavioral repertoire
- DSpecific neural structures or behaviors of interest
- EAll of the above
8Which of the following type of glial cell myelinates peripheral axons?
- ASchwann Cells
- BOligodendrocytes
- CAstrocytes
- DMicroglia
- EAll of the above
9Representation of which of the following is best accomplished using a topographic map?
- AThe visual world
- BObjects
- COdors
- DEpisodic Memory
- EVerbs and Nouns
10Which of the following is not a true statement about a center-surround receptive field?
- AIt can be mapped by electrophysiological recording techniques.
- BIt is characterized by a circular center and a donut-shaped surround.
- CIt can involve an excitatory response (e.g., to touch).
- DIt can involve an inhibitory response (e.g., to touch).
- EIt is found only in primary sensory cortex.
- AIt can be mapped by electrophysiological recording techniques.
11The type of nerve cell that synapses upon muscles is called a(n)
- Adorsal root neuron
- Bcranial neuron
- Cafferent neuron
- Dmotor neuron (or motorneuron)
- Espinal interneuron
12Which of the following is not considered to be a “model” organism?
- AZebrafish
- BFruit fly
- CThe nematode C. elegans
- DMouse
- EThe marine snail Aplysia
13The set of neurons and small ganglia associated with the digestive tract is called the _______ nervous system.
- APeripheral
- Bautonomic
- Centeric
- Dsympathetic
- Eparasympathetic
14The structural brain imaging technique that relies on atoms behaving as small magnets is called
- AMRI
- BfMRI
- CPET
- DSPECT
- ECT
15Which of the following statements about the expression of genes in the nervous system is true?
- AEvery gene in the human genome is expressed in the CNS.
- BThere are tens of thousands of neuron-specific genes (i.e., genes that are not expressed outside the CNS).
- CMost of the genes in the human genome are expressed in the CNS.
- DHumans have 100 times more genes than invertebrate animals such as Drosophila.
- EHumans have three to four times more genes than mice have.
- AEvery gene in the human genome is expressed in the CNS.
16The scientist who shared the Nobel Prize with Camillo Golgi for his anatomical studies of the CNS was
- AAllesandro Volta
- BLuigi Galavani
- CSantiago Ramon y Cajal
- DLouis Pasteur
- EThomas Hodgkin
17Cognitive neuroscience is concerned with
- Amathematical ability
- Bemotions
- Clanguage
- Dabstract thought
- Eall of the above
18The brain imaging technique that makes use of a narrow X-ray beam is called
- AMRI
- BfMRI
- CPET
- DSPECT
- ECT
19A neuron that innervates (i.e., makes synaptic contact with) a large number of other neurons
- Arepresents convergent neural signaling.
- B represents divergent neural signaling.
- Crepresents massive neural integration.
- Dmust fire at very high frequencies to be useful.
- Ecan fire only at very low frequencies.
- Arepresents convergent neural signaling.
20The technique that first revealed the tremendous diversity of neuronal cell types (numbering in the hundreds or thousands in vertebrate animals) is called
- Athe Nissl stain
- Bthe Golgi stain
- Ccresyl violet staining
- Dfluorescence staining
- Eelectron microscopy
21Which of the following best describes nerve cells?
- ANerve cells are exceptionally good conductors of electricity (much better than copper wires).
- BNerve cells are similar in their electrical conduction properties to copper wires.
- CIn comparison to copper wires, nerve cells are relatively poor conductors of electricity.
- DNerve cells are unable to conduct electricity under any circumstances.
- ENerve cells are electron sinks: they absorb many electrons, but no electricity comes out of them.
22The resting membrane potential is not exactly equal to the Nernst potential for potassium because
- Athe Nernst equation is not able to predict potentials that precisely.
- Brapid fluctuations in membrane potential prevent accurate measurements.
- Cthe membrane has some resting permeability to species other than potassium.
- Dpotassium does not contribute to the resting membrane potential.
- EAll of the above
- Athe Nernst equation is not able to predict potentials that precisely.
23Which of the following is not a cause of sensory receptor potentials?
- AHeat
- BPressure
- CSounds
- DChemicals
- EBrain Waves
24he equation used to calculate membrane potential when there are multiple permeant ions is called the _______ equation.
- ANerst
- Bionic imbalance
- CGoldman
- DFinch and Augustine
- Eatomic permeability
25Which of the following statements about ionic distributions in nerve cells is false?
- APotassium is higher inside cells than outside cells.
- BSodium is higher outside cells than inside cells.
- CChloride is higher outside cells than inside cells.
- DCalcium is higher outside cells than inside cells.
- EThe total concentration of all ionic species is approximately the same for all nerve cells in all animals.
- APotassium is higher inside cells than outside cells.
26Which of the following statements about action potentials is false?
- AThey can transmit signals over long distances.
- BThey boost the spatial spread of electrical signals.
- CThey are elicited by hyperpolarization.
- DThey occur at threshold.
- EThey are all-or-none.
- AThey can transmit signals over long distances.
27A measured membrane potential of +58 mV would be consistent with _______ inside the cell and _______ outside the cell.
- A100 mM K+, 10 mM K+
- B 10 mM Na+, 100 mM Na+
- C10 mM Cl-, 100 mM Cl-
- D100 mM K+, 100 mM Na+
- EAll of the above
- A100 mM K+, 10 mM K+
28The different electrical signals occurring in nerve cells are caused by _______ the cell membrane.
- Apositive charges bound to the inner and outer faces of
- Bnegative charges bound to the inner and outer faces of
- Cmovements of charged proteins within the plane of
- Dfluxes of ions across
- Epatterns of electrical eddy currents inside
- Apositive charges bound to the inner and outer faces of
29Which of the following is not necessary for neurons to communicate electrically?
- AConsumption of metabolic energy
- BUse of active transporters to create ionic gradients
- CSeparation of large amounts of electrical charge, with excess positive charges stored inside the cell
- DSelective permeability of the cell membrane via different kinds of ion channels
- EChanges in membrane potential caused by the movement of ions across the cell membrane
- AConsumption of metabolic energy
30Hodgkin and Katz proposed that sodium was the predominant ion associated with the firing of an action potential because
- A the membrane potential approaches the Na+ Nernst potential during the rising phase.
- Bthe membrane potential approaches the Na+ Nernst potential during the falling phase.
- Csodium ions can move more quickly than other ionic species.
- Dsodium ions are the only ions that can flow into the nerve cell body.
- Ethe sodium gradient explains the rising phase, falling phase, and overshoot of the action potential.
31Which of the following is not a reason for the usefulness of the squid giant axon in neuronal studies?
- AThe large size of the axon makes it easy to penetrate with recording electrodes.
- BThe axoplasm can be extruded, thus allowing studies of its composition.
- CLarge synapses between giant nerve cells make them easy to study.
- DCorrect Giant ion channels allow for the insertion of recording electrodes into the channels.
- EProperties of the squid’s axons and synapses can be related to its behavior
- AThe large size of the axon makes it easy to penetrate with recording electrodes.
32Studies of the ionic basis of the action potential in squid giant axon found that
- Adecreasing sodium outside the cell decreases the size of the action potential.
- Bdecreasing sodium outside the cell increases the size of the action potential.
- Cdecreasing potassium outside the cell decreases the size of the action potential.
- Ddecreasing potassium outside the cell increases the size of the action potential.
- Emanipulating sodium has large effects on both the size of the action potential and the resting membrane potential.
- Adecreasing sodium outside the cell decreases the size of the action potential.
33The transmembrane potential is generated by
- Arepulsion of positive and negative charges.
- Bdiffusion of ions down a concentration gradient.
- Cthe greater mobility of small ions.
- Dthe selectivity of the membrane to pass positive charges only.
- EAll of the above
- Arepulsion of positive and negative charges.
34Which of the following statements about the ionic permeability of cell membranes is false?
- AThe permeability of some ions can be very low.
- BThe permeability of some ions can change over time.
- CIn resting nerve cells, the membrane is quite permeable to potassium.
- DIn resting nerve cells, the membrane is quite permeable to sodium.
- EAll of the above statements are true.
- AThe permeability of some ions can be very low.
35Which of the following factors is important in determining the membrane potential when there are multiple permeant ions?
- AThe concentration gradient of the individual ionic species
- BThe permeability of the membrane to the individual ionic species
- CThe sum total of all of the ions on both sides of the membrane
- DBoth a and b
- EAll of the above
- AThe concentration gradient of the individual ionic species
36The synaptic potential
- Amakes communication between nerve cells possible.
- Boccurs only in response to external stimuli.
- Cpropagates along axons.
- Ddetermines the cell’s resting potential.
- EAll of the above
- Amakes communication between nerve cells possible.
37Which of the following is not a usual kind of potential exhibited by nerve cells?
- AResting membrane
- BAction
- CReaction
- DReceptor
- ESynaptic
- AResting membrane
38Which of the following statements about electrochemical equilibrium is false?
- AElectrochemical equilibrium involves the movement of a relatively small number of ions.
- BIonic gradients are necessary for the generation of the membrane potential.
- CThe size of the potential is proportional to the size of the ion gradient.
- DThe direction of the ion gradient determines the polarity of the membrane potential.
- EFor a given ion concentration gradient, the resulting potential is independent of the number of charges on the ion.
- AElectrochemical equilibrium involves the movement of a relatively small number of ions.
39Typically, neurons firing action potentials encode a signal’s intensity by
- Achanging the size of their action potentials.
- BCorrect changing the frequency of their action potentials.
- Cfiring at precise moments so as to signal different sized signals.
- Dsending signals of different sizes down different axonal branches.
- EAll of the above
- Achanging the size of their action potentials.
40In their studies of the resting membrane potential of the squid giant axon, Hodgkin and Katz found that
- Aincreasing potassium outside the axon depolarized the axon’s potential.
- Bincreasing potassium outside the axon hyperpolarized the axon’s potential.
- Cincreasing sodium outside the axon depolarized the axon’s potential.
- Dincreasing sodium outside the axon hyperpolarized the axon’s potential.
- Echanging external sodium and potassium had identical effects on the resting axon potential.
- Aincreasing potassium outside the axon depolarized the axon’s potential.
41Which of the following is not an observation that helped to identify sodium as the early current of the action potential?
- AThe current declined when there was decreased driving force on sodium fluxes.
- BThe current disappeared near the Nernst potential for sodium.
- CThe early current was blocked by tetrodotoxin.
- DThe early current was unaffected by tetraethylammonium.
- EWhen the late current was blocked, the reversal potential of the inward current shifted to a negative membrane potential.
- AThe current declined when there was decreased driving force on sodium fluxes.
42In an experiment using a series of voltage steps to study the two different ionic currents associated with the action potential (as shown in Figure 3.2), it was found that
- Aboth currents had the exact same voltage dependence.
- Bboth currents increased monotonically with increasingly large voltage steps.
- Cboth currents decreased with increasingly large voltage steps.
- Dthe early current increased initially, but then it decreased in size as the voltage step was increased.
- Ethe late current increased initially, but then it decreased in size as the voltage step was increased.
- Aboth currents had the exact same voltage dependence.
43Which of the following statements about myelination is false?
- AMyelin sheaths are created by glial cells.
- BMyelin serves to sharply increase the time constant of the axon.
- CMultiple layers of closely opposed glial membranes wrap the axon and serve as an electrical insulator.
- DMyelin is absent at the nodes of Ranvier.
- ESodium and potassium channels are clustered at the nodes of Ranvier.
- AMyelin sheaths are created by glial cells.
44The mode of action potential propagation along myelinated axons is called
- Asalutatory
- Bscleorid
- Coligodendroid
- Dranvierian.
- Ehyperian
45Which of the following was not seen in the voltage-clamp study of squid action potentials?
- ACapacitive currents in response to hyperpolarizing voltage steps
- BCapacitive currents in response to depolarizing voltage steps
- CA transient inward current as a result of depolarization
- D A sustained outward current as a result of hyperpolarization
- EAll of the above were seen in squid giant axons.
- ACapacitive currents in response to hyperpolarizing voltage steps
46Voltage clamp data, in which investigators analyzed membrane conductances during action potentials, showed all of the following except
- Athe sodium current was rapidly activated by depolarization.
- Bthe potassium current activates on a comparatively slow time scale of a few ms.
- Cat certain potentials, there can be zero current even with a large conductance.
- Ddepolarization leads to a time-dependent inactivation of the sodium current.
- Edepolarization leads to a time-dependent inactivation of the potassium current.
- Athe sodium current was rapidly activated by depolarization.
47For which of the following reasons was the development of the voltage clamp critical to investigations of the ionic basis of the action potential?
- AVoltage changes in the cell cannot be seen without voltage clamp.
- BIonic conductances can be activated only in cells that have been voltage clamped.
- CVoltage clamping allows simultaneous control of membrane potential and measurement of permeability changes.
- DSodium and potassium currents are activated in non-overlapping voltage regimes.
- EAll of the above
- AVoltage changes in the cell cannot be seen without voltage clamp.
48The inventor of voltage clamp was
- AKenneth Cole.
- BAlan Hodgkin.
- CAndrew Huxley.
- DBernard Katz.
- EAlessandro Volta.
- AKenneth Cole.
49Which of the following statements on either the rising or overshoot phase of the action potential is false?
- AThe time from threshold to maximum depolarization is essentially instantaneous (i.e., too fast to be measured accurately with current electronics).
- BA positive feedback loop leads to a regenerative depolarization that would increase continuously if unchecked.
- CThe degree of depolarization is limited in part by the declining driving force on sodium entry.
- DThe degree of depolarization is limited in part by the inactivation time course for the sodium current.
- EThe degree of depolarization is limited in part by the activation time course of the potassium current.
- AThe time from threshold to maximum depolarization is essentially instantaneous (i.e., too fast to be measured accurately with current electronics).
50Neurons exhibit a threshold above which an action potential is triggered because of
- Aa positive feedback loop between sodium current activation and potassium inactivation.
- Ba positive feedback loop between depolarization and sodium current activation.
- Ca negative feedback loop between sodium current activation and inactivation.
- Dthe precise time constant of sodium channel activation (i.e., a threshold would not be observed if this were measurably changed).
- Epacemaker-like activity that is present in all nerve cells.
- Aa positive feedback loop between sodium current activation and potassium inactivation.
51Which of the following is not integral to the action potential waveform?
- AA change in permeability of the membrane to sodium
- BA change in permeability of the membrane to potassium
- CA transient increase in the sodium current
- D An initial decrease in the potassium current
- EA “self-activating” aspect to the rise in the sodium current
- AA change in permeability of the membrane to sodium
52Which of the following statements about multiple sclerosis (MS) is false?
- AMS is characterized by demyelination of axons along with some axon loss.
- BIt was recently proven that all cases of MS are due to persistent infection by a tropical parasite.
- CCases of MS vary considerably in terms of severity and progression of the illness.
- DSymptoms of MS may include weakness, paralysis, double vision, monocular blindness, and abnormal somatic sensations.
- EMagnetic resonance imaging can help diagnose some cases of MS.
- AMS is characterized by demyelination of axons along with some axon loss.
53Which of the following was shown to eliminate the early inward current in squid giant axons?
- ARemoval of external sodium
- BDoubling of external sodium
- CRemoval of external potassium
- DDoubling of external potassium
- ERemoval of all external cations
- ARemoval of external sodium
54Action potentials are generated
- Aat most subthreshold voltages.
- Bonly when the cell reaches threshold.
- Conly when the membrane potential exceeds threshold by 5 to 10 millivolts.
- Dintermittently, but usually when the membrane potential exceeds threshold.
- Eonly after all of the sodium channels are open.
- Aat most subthreshold voltages.
55The _______ most directly affects the rate of information processing within the central nervous system.
- Anumber of sodium channels along an axon
- Bnumber of potassium channels along an axon
- Cpropagation speed of action potentials
- Dthreshold voltage of neurons
- Eratio of sodium to potassium channels
- Anumber of sodium channels along an axon
56Which of the following statements about the spread of electrical signals/currents along an axon is false?
- AThe spread of a passive signal is limited by the leakage of current out of the axon.
- BThe time course of passive signal spread slows with increasing leakiness of the axon.
- CThe membrane length constant describes how far an action potential can propagate along an axon.
- DAction potentials can propagate for long distances without decrement.
- EAction potential propagation requires both current flow along the axon and ion fluxes across the axon membrane.
- AThe spread of a passive signal is limited by the leakage of current out of the axon.
57Which of the following explains the unidirectional propagation of action potentials?
- AThe voltage dependence of the sodium channels
- BThe voltage dependence of the potassium channels
- CThe presence of a refractory period at a location where an action potential has just passed
- DSufficient “leakiness” of the axons, such that backward propagation of action potentials is prevented
- EThe polarized orientation of microtubules within the axon
- AThe voltage dependence of the sodium channels
58When current is injected into an axon,
- Aan action potential is evoked before the current has spread any distance from the point of injection.
- Bthe current will spread only in one direction.
- Cthe current will spread passively only if it is a depolarizing current.
- Dthe current will decay exponentially with increasing distance from the injection site (if no action potential is present).
- Ethe current will propagate as an oscillating wave independently of its polarity.
- Aan action potential is evoked before the current has spread any distance from the point of injection.
59Which of the following does not stem from the application of Ohm’s law to ionic conductances?
- AThe driving force on the ionic current is the difference between the membrane potential and the ion’s Nernst potential.
- BThe conductance for an ion is inversely proportional to the resistance of the membrane to the passage of that ion.
- CAll permeant ions experience an identical driving force at each time point during the course of an action potential.
- DThe conductance for each ion can be calculated based on the measured ionic currents and the calculated driving force.
- EThe calculations stemming from Ohm’s law can be used to derive a mathematical description of the action potential.
- AThe driving force on the ionic current is the difference between the membrane potential and the ion’s Nernst potential.
60Which of the following was not one of the features of Hodgkin and Huxley’s mathematical model?
- AThe action potential can be reconstructed based entirely upon the time course and amplitudes of the ionic conductances.
- BThe fast-rising phase can be accounted for by selective sodium entry.
- CThe model mimics the experimentally measured refractory period.
- DThe falling phase can be at least partially accounted for by the activation time course of the potassium current.
- EThe undershoot can be accounted for by the time course of sodium current reactivation.
- AThe action potential can be reconstructed based entirely upon the time course and amplitudes of the ionic conductances.
61Which of the following is the main reason that the opening of sodium channels causes a very rapid depolarization of most neurons?
- AThe movement of a sodium ion produces a larger voltage change than the movement of other ions.
- BSodium ion diffusion proceeds so quickly that whenever sodium channels are open, there is a rapid directional flux across the membrane.
- CThe conjunction of the sodium gradient and the negative membrane potential produces a very large driving force on sodium ions.
- DAll of the above
- ENone of the above
- AThe movement of a sodium ion produces a larger voltage change than the movement of other ions.
62In familial hemiplegic migraine, the underlying mutation in a calcium channel causes
- Aabnormally functioning pain receptors in the peripheral nervous system.
- Benhanced synaptic excitation of second-order pain-sensitive neurons.
- Cabnormal activation of thalamic pain centers.
- Dabnormal activation of neocortical pain centers.
- Ethe syndrome by some unknown mechanism
- Aabnormally functioning pain receptors in the peripheral nervous system.
63In which of the following ways do potassium channels in the squid giant axon differ from sodium channels?
- AThe potassium channels pass only a few ions per second.
- BThe potassium channels show little voltage dependence.
- CThe summing of the individual potassium channels does not reconstruct the macroscopic current.
- DOnce the potassium channels open in response to a voltage step command, they tend to remain open.
- EAll of the above
- AThe potassium channels pass only a few ions per second.
64Which of the following ligand-gated ion channels is (are) not regulated primarily by an intracellular signal?
- AThe IP3 receptor located on the endoplasmic reticulum
- BThe potassium-activated calcium channel
- CThe glutamate receptor
- DThe cAMP- and cGMP-gated ion channels
- EThe acid-sensing ion channels
- AThe IP3 receptor located on the endoplasmic reticulum
65Paddle-like, charged transmembrane domains of potassium channels may
- Aserve as a plug or inactivation gate.
- Bbe the primary voltage sensors
- Cconfer ion selectivity to the channel.
- Denable the aggregation of channel subunits into functional channels.
- EAll of the above
- Aserve as a plug or inactivation gate.
66The proteins that establish ionic gradients are called
- Apassive transporters.
- Bactive transporters.
- Cvoltage-gated ion channels.
- Dligand-gated ion channels.
- Epermeability transition pores.
- Apassive transporters.
67The calcium ATPase
- Ais much simpler than the sodium–potassium pump because it has only three transmembrane regions.
- Bpumps 15 calcium ions for each molecule of ATP consumed.
- Cuses the same intracellular domain for both nucleotide binding and ion translocation.
- Dpumps calcium in a cyclical process that utilizes energy from ATP.
- Eis unique among transporters in that its pumping action involves no conformational changes.
- Ais much simpler than the sodium–potassium pump because it has only three transmembrane regions.
68Which of the following is a common, defining feature of membrane-bound active ion transporters?
- AAll transporters are electrogenic.
- BAll transporters transport two or more different ions.
- CAll catalyze the conversion of ATP to ADP.
- DAll are able to move at least one ion against its concentration gradient.
- EAll of the above
- AAll transporters are electrogenic.
69In the operation of sodium–potassium ATPase,
- Athere is an obligatory coupling of sodium efflux and potassium influx.
- Bthis transporter (or “pump”) is electrogenic.
- Cphosphorylation and dephosphorylation are respectively associated with the sodium and potassium transport steps.
- Dthe pump transports two potassium ions for every three sodium ions.
- EAll of the above
- Athere is an obligatory coupling of sodium efflux and potassium influx.
70Individual ion channels
- Awere visualized with the advent of the voltage clamp in 1956.
- Bshow the same time course as macroscopic ionic currents.
- Cmay pass thousands of ions per millisecond.
- Dhave a different voltage dependence than the macroscopic ionic current has.
- Ehave a different reversal potential than the macroscopic ionic current has.
- Awere visualized with the advent of the voltage clamp in 1956.
71Which of the following was not observed in studies measuring the efflux of radioactive sodium from the squid giant axon?
- ADramatic increase of efflux during a brief train of action potentials
- BSharp drop in efflux when extracellular potassium was removed
- CDependence of efflux upon the presence of ATP
- DDecrease of efflux when mitochondrial ATP synthesis was inhibited
- EAll of the above were observed.
72A surprising result that emerged from the molecular analysis of ion channels was the
- Asize of the individual ion channels.
- Bvoltage-dependence of the ion channels.
- Ctime-dependence of the ion channels.
- Ddiscovery of differences in ionic selectivity.
- Esheer number of different ion channels.
- Asize of the individual ion channels.
73Which of the following appears to contribute to the selectivity filter of the potassium channel?
- AThe channel pore narrows to fit the size of a non-hydrated potassium ion.
- BCations such as cesium are too large to pass through the pore.
- CCations such as sodium are too small to be dehydrated at the pore filter.
- DAll of the above
- ENone of the above
- AThe channel pore narrows to fit the size of a non-hydrated potassium ion.
74Which of the following statements regarding the diversity of ion channels is false?
- AWith only six different types, potassium channels are the least diverse channel type.
- BThere are at least 10 different sodium channels in humans.
- CSodium channels that do not inactivate have been found.
- DThere are least 10 different types of calcium channels.
- ECalcium channels serve diverse functions such as influencing action potential shape and mediating the release of neurotransmitters.
75Which of the following is not a variant of the patch clamp technique?
- ACell attached
- B Intracellular
- CWhole cell
- DInside–out patch
- EOutside–out patch
- ACell attached
76The TRP ion channel family includes channels responsive to
- Acomplex sequences of voltage commands.
- Bheat and cold.
- Cintracellular cyclic nucleotides.
- Dhyperpolarization.
- Eultraviolet light.
- Acomplex sequences of voltage commands.
77The technique that provides the most direct information about the physical, three-dimensional structure of ion channels is
- Athe sequencing of the channel’s amino acids.
- Bphysiological measurements of ion selectivity.
- CX -ray crystallography
- Dfluorescence imaging of channel subunit dynamics.
- EAll of the above provide similar information on the channel’s three-dimensional structure.
- Athe sequencing of the channel’s amino acids.
78Which of the following is not a type of ion transporter that has been observed?
- AThe sodium/calcium exchanger
- BThe sodium/potassium/chloride co-transporter
- CThe sodium/neurotransmitter co-transporter
- DThe sodium/proton exchanger
- EAll of the above transporters have been observed.
- AThe sodium/calcium exchanger
79Which of the following is a major advantage to researchers of the Xenopus oocyte expression system?
- AXenopus is the only lower vertebrate whose genome has been sequenced.
- BThe unusually small size of the eggs makes patch-clamping relatively easy.
- CThe oocytes have many endogenous ion channels to which exogenous channels can be compared.
- DThe oocytes have quite thin membranes, which amplifies the ionic currents.
- E It facilitates physiological characterization of modified ion channel genes.
- AXenopus is the only lower vertebrate whose genome has been sequenced.
80Animal toxins have been discovered that
- Ablock sodium channels.
- Bprolong the open state of sodium channels.
- Calter the voltage-dependence of sodium channels.
- Dblock potassium channels.
- E All of the above
- Ablock sodium channels.
81The two main families of neurotransmitter receptors are _______ and _______.
- Aligand-gated; ion-gated
- B ionotropic; metabotropic
- Cvoltage-gated; voltage-modulated
- Dcationic; anionic
- Eexcitatory; inhibitory
- Aligand-gated; ion-gated
82Gap junctions (electrical synapses)
- Aare found only in a few species of animals.
- Bare far more numerous than chemical synapses.
- Chave larger pores than voltage-gated ion channels.
- Dare found only where there are large gaps between nerve cells.
- Eare used to pass chemical neurotransmitters.
- Aare found only in a few species of animals.
83Listed below are the individual events that make up chemical synaptic transmission:
Diffusion of transmitter across the synaptic cleft
Depolarization of the presynaptic terminal
Vesicle fusion with plasma membrane
Opening of voltage-gated ion channels
Activation of presynaptic, calcium-sensitive proteins- Aa; b; c; d; e
- B
b; d; e; c; a - Cb; e; d; c; a
- De; d; b; c; a
- Ea; b; d; e; c
- Aa; b; c; d; e
84Black widow spider venom is thought to disrupt the functioning of nerve terminals by
- Aproteolytic cleavage of SNARE proteins.
- Bcircumventing the calcium-regulatory step of exocytosis to promote massive exocytosis.
- Cbinding to all molecules of synapsin, synaptotagmin, and synaptophysin and thereby preventing their normal functioning.
- Dpunching holes in vesicles and thereby causing release of their contents into the cytosol.
- Eblocking calcium channels.
- Aproteolytic cleavage of SNARE proteins.
85Compared with normals, the decrease in quantal size observed in familial infantile myasthenia would be most consistent with
- Afewer calcium channels in the presynaptic terminals.
- Ba greater rate of spontaneous exocytosis depleting the size of the vesicle pool.
- Csmaller synaptic vesicles.
- Da change in the sensitivity of the calcium release mechanism.
- Ea loss of all ACh receptors at the neuromuscular junction.
- Afewer calcium channels in the presynaptic terminals.
86In tracking recycling of synaptic vesicles, using HRP as a vesicle marker, the observed sequence of movements of HRP was
- AEndosome, coated vesicle, vesicle reserve pool
- BVesicle reserve pool, coated vesicle, endosome
- CEndosome, vesicle reserve pool, coated vesicle
- DCoated vesicle, vesicle reserve pool, endosome
- ECoated vesicle, endosome, vesicle reserve pool
- AEndosome, coated vesicle, vesicle reserve pool
87Which of the following statements about postsynaptic currents at the neuromuscular end plate is false?
- ADepolarizing currents can be recorded from outside–out patches of postsynaptic membrane.
- BIndividual channels tend to stay open for no more than a few msec.
- CAcetylcholine can induce openings of ligand-gated ion channels.
- DThe end plate potential is due to the opening of thousands or millions of channels.
- E The end plate channels show a regenerative opening pattern that propagates an action potential along the length of the muscle fiber.
- ADepolarizing currents can be recorded from outside–out patches of postsynaptic membrane.
88Miniature end-plate potentials, or MEPPs, are produced
- Aat miniature end-plates.
- Bby the smallest axons.
- Cin response to weak stimuli.
- Dby the smallest neurotransmitters.
- E by spontaneous release of neurotransmitter.
- Aat miniature end-plates.
89To date, which of the following is not part of the experimental evidence favoring the vesicular release hypothesis of neurotransmission?
- AFixed size of MEPPs
- BQuantized distribution of events occurring at the neuromuscular junction
- CVisualization of synaptic vesicles using electron microscopy
- DCorrespondence between a vesicle’s acetylcholine content and MEPP size
- EVisualization of acetylcholine molecules diffusing out of the neck of the membrane-fused vesicle
- AFixed size of MEPPs
90The most important factor determining whether a receptor-operated ion channel is inhibitory or excitatory is
- Athe ligand-binding properties of the receptor.
- Bwhether the permeant ion is positively or negatively charged.
- Cwhether the permeant ion’s reversal potential is positive or negative.
- Dwhether the permeant ion’s reversal potential is positive or negative to threshold
- ENone of the above
- Athe ligand-binding properties of the receptor.
91Which of the following statements about EPSPs in the central nervous system is false?
- AThey are much larger than end plate potentials.
- BEPSPs occurring close together in time can summate and help bring a neuron to threshold.
- CMultiple EPSPs arriving together at different locations on the dendritic tree can summate and help bring a neuron to threshold.
- DTheir effect in the central nervous system can be nullified by IPSPs.
- EAll of the above are false; none is true.
- AThey are much larger than end plate potentials.
92Activating end plate acetylcholine receptor channels produces 0 current at 0 mV, but is still able to elicit action potentials in muscle fibers because
- Athe depolarization occurs so quickly that the membrane potential goes far positive to 0 mV and produces an overshooting action potential.
- Bthere are enough acetylcholine receptors to propagate the action potential along the length of the muscle fiber.
- Cthe receptor is also permeable to calcium, which binds to other channels to elicit action potentials.
- Ddepolarization of the membrane to 0 mV is sufficient to bring nearby membrane regions, which contain voltage-gated sodium channels, to threshold.
- ENone of the above; acetylcholine does not elicit muscle action potentials
- Athe depolarization occurs so quickly that the membrane potential goes far positive to 0 mV and produces an overshooting action potential.
93Gap junctions may exhibit all of the following features except for the ability to
- Apass small metabolites, including some second messengers.
- Bpass electrical current bidirectionally.
- Cpass electrical current unidirectionally.
- D amplify small incoming electrical signals into large regenerative potentials.
- Esynchronize the activity of populations of nerve cells.
- Apass small metabolites, including some second messengers.
94When a muscle fiber is held at a voltage of 0 mV at the neuromuscular end plate, acetylcholine no longer produces a current because
- Athe acetylcholine receptor channels all close instantly at 0 mV.
- Ban influx of sodium is balanced by an equal efflux of potassium.
- Cthe membrane conductance for each permeant ion is 0 at 0 mV.
- Dat 0 mV, the potassium ions lodge in the receptor channel and block the influx of sodium.
- Ethe Nernst potentials for both sodium and potassium are 0 mV in muscle fibers.
- Athe acetylcholine receptor channels all close instantly at 0 mV.
95The differential release of small, clear vesicles, versus large, dense-core vesicles, is best explained by
- Abiophysical differences in the vesicles’ lipids that allow for easier fusion of small vesicles.
- Ba more sensitive calcium-release mechanism on the dense-core vesicles.
- Ca more delocalized calcium signal generated by intense neural stimulation.
- Dthe presence of novel fusion proteins on the dense core vesicles that bind neuropeptides.
- EAll of the above
- Abiophysical differences in the vesicles’ lipids that allow for easier fusion of small vesicles.
96SNARE proteins participate in vesicle exocytosis by
- Aforming a protein coat that maintains the vesicle’s integrity.
- Bbinding calcium and then forming a pore into the vesicle.
- Cforming a protein complex that pulls the vesicle membrane against the plasma membrane.
- Dlinking calcium channels to exocytotic fusion sites.
- Epushing vesicles from the reserve pool into the docked pool.
- Aforming a protein coat that maintains the vesicle’s integrity.
97The protein that is thought to cross-link vesicles to actin to form a reserve vesicle pool is called
- Asynapsin.
- Bsynaptotagmin.
- Csynaptobrevin.
- Dsynaptophysin.
- Esnap 25.
98Which of the following is an accepted criterion for defining a molecule to be a neurotransmitter?
- AIt must be present in the presynaptic terminal.
- BIt must be released in response to presynaptic electrical activity.
- CIt must exert an effect on the postsynaptic cell.
- DAll of the above
- ENone of the above
- AIt must be present in the presynaptic terminal.
99The capability of a nerve terminal to rapidly and dramatically produce very large changes in calcium levels is most dependent on the
- Apresence of calcium-selective ion channels.
- B enormous gradient of calcium across the membrane
- Cfact that calcium is a positively charged ion.
- Dfact that calcium is a divalent cation.
- EAll of the above are essential for producing large, rapid concentration changes.
- Apresence of calcium-selective ion channels.
100Which of the following experiments would indicate a role for calcium in transmitter secretion?
- AObservation of presynaptic depolarizing currents after blockade of sodium channels
- BVoltage clamp experiments showing voltage-gated calcium channels in the presynaptic terminal
- CInduction of transmitter release by injection of calcium into the presynaptic terminal
- DBlockade of transmitter release by injection of calcium buffer into the presynaptic terminal
- E All of the above
- AObservation of presynaptic depolarizing currents after blockade of sodium channels
101Acetylcholine is used as a neurotransmitter at
- Athe neuromuscular junction.
- Bpreganglionic synapses of the autonomic (visceral motor) nervous system.
- Cpostganglionic synapses of the parasympathetic nervous system.
- Dwidely distributed synapses in the central nervous system.
- EAll of the above
- Athe neuromuscular junction.
102Excitotoxicity
- Acan result from very brief (sub-millisecond) increases in glutamate levels.
- Bcan be prevented by administration of glutamate receptor antagonists after a stroke has been diagnosed.
- Chas not been correlated with the potency of compounds at glutamatergic receptors.
- D can occur in some forms of epilepsy and head trauma.
- Ehas been linked to a specific intracellular signaling pathway that activates a family of excitotoxicity genes.
- Acan result from very brief (sub-millisecond) increases in glutamate levels.
103Glutamate is
- Athe most commonly used neurotransmitter in the brain.
- Bneurotoxic at high concentrations.
- Ca nonessential amino acid.
- Doften synthesized from glial-synthesized glutamine.
- Eall of the above
- Athe most commonly used neurotransmitter in the brain.
104Serotonin reuptake blockers such as fluoxetine (Prozac) are used clinically
- Ato treat hypertension.
- Bto treat panic disorders.
- Cas antidepressants.
- Das antipsychotics.
- Eto treat generalized anxiety.
- Ato treat hypertension.
105Peptide neurotransmitters are often released
- Ashortly after their synthesis in presynaptic terminals.
- Bas pre-propeptides.
- Cas propeptides.
- Dmore readily and quickly than nonpeptide transmitters.
- Etogether with nonpeptide transmitters.
- Ashortly after their synthesis in presynaptic terminals.
106The presence of which of the following compounds or proteins in a cell makes it quite likely that the cell is a GABAergic neuron?
- APyridoxal phosphate
- BGlutamic acid decarboxylase
- CGABA transaminase
- Dγ-hydroxybutyrate
- EGlutamine
- APyridoxal phosphate
107One typically finds _______ subunits in the nicotinic acetylcholine receptors.
- Atwo
- Bthree
- Cfive
- Dseven
- Enine
- Atwo
108Listed below are the five steps in a nitric oxide (NO)-mediated signaling event.
1. Calcium binds to calmodulin
2. Activation of nitric oxide synthase
3. NO diffusion for tens of micrometers
4. Activation of guanylyl cyclase
5. Inactivation by reaction with oxygen- A1; 2; 3; 4; 5
- B5; 4; 3; 2; 1
- C4; 2; 3; 1; 5
- D2; 3; 4; 1; 5
- E1; 5; 2; 3; 4
- A1; 2; 3; 4; 5
109In terms of size, which of the following are the largest neurotransmitters?
- ABiogenic amines
- BAmino acid transmitters
- CNeuropeptide transmitters
- DPurinergic transmitters
- EGaseous transmitters
- ABiogenic amines
110Based upon the distribution of endocannabinoid receptors in the brain, it can be surmised that these compounds have a likely influence on
- Aneocortex.
- Bthe hippocampus.
- Cbasal ganglia.
- Dthe hypothalamus.
- EAll of the above
- Aneocortex.
111Which of the following is not a catecholamine?
- ADopamine
- BHistamine
- CNorepinephrine
- DEpinephrine
- EAll of the above are catecholamines.
112Which of the following is not a class of opioid peptides?
- ADynorphins
- BEndorphins
- CEnkephalins
- DEndocannabinoids
- EAll of the above are opioid peptides.
113Which of the following receptor types can be modulated by both barbiturates and benzodiazepines?
- AGABAA
- BGABAB
- CGABAC
- DGlycine
- EMuscarinc ACh receptor
114The banded krait uses the neurotoxin _______ to paralyze its prey.
- Anicotine
- Bmuscarine
- Cconotoxin
- Dα-bungarotoxin
- Eδ-tubocurarine
115Cocaine acts
- Aon GABAA receptors.
- Bas an MAO inhibitor.
- Cby blocking serotonin reuptake.
- Dby blocking dopamine reuptake.
- Eby blocking biogenic amine vesicular transporters.
- Aon GABAA receptors.
116Which of the following is not a feature of glutamate signaling systems?
- AThe presence of multiple glutamate receptor families with different ionic selectivities
- BVoltage-dependent gating of certain types of glutamate receptor
- Cthe passage of large amounts of magnesium and calcium by NMDA receptors
- DThe use of specialized proteins for loading glutamate into vesicles
- EThe use of specialized proteins for removing glutamate from the synaptic cleft
- AThe presence of multiple glutamate receptor families with different ionic selectivities
117Myasthenia gravis is characterized by
- Adegeneration of lower motoneurons.
- Bdegeneration of upper motoneurons.
- Cmutations affecting the synthesis of acetylcholine.
- Dmutations affecting acetylcholine receptors.
- Ean autoimmune attack on acetylcholine receptors.
- Adegeneration of lower motoneurons.
118The transmitter GABA excites immature cortical neurons because
- Aimmature GABA receptors pass more sodium than chloride.
- Bimmature GABA-receptive neurons have a more negative firing threshold than mature neurons.
- Cimmature GABA-receptive neurons express many Na+/K+/Cl– co-transporters.
- Dimmature GABA-receptive neurons express many K+/Cl– co-transporters.
- Ethe opening of GABA receptor channels tends to excite immature cortical networks because of the networks’ wiring.
- Aimmature GABA receptors pass more sodium than chloride.
119While 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?
- AIts presence in many inhibitory neurons
- BIts ability to block the reuptake of inhibitory transmitters
- CIts actions as a cofactor at glycine receptors
- DThe consequences of xanthine (e.g., caffeine) blockade of adenosine receptors
- EThe co-localization of adenosine with GABA in GABAergic synaptic vesicles
- AIts presence in many inhibitory neurons
120Listed below are the enzymes needed to synthesize epinephrine (adrenaline):
1. Dopamine beta-hydroxylase
2. Tyrosine hydroxylase
3. Phenylethanolamine-N-methyl transferase
4. DOPA decarboxylase- A2; 4; 1; 3
- B3; 1; 4; 2
- C2; 1; 3; 4
- D1; 2; 4; 3
- E2; 4; 3; 1
- A2; 4; 1; 3
121Which of the following is an “effector” of G-protein-initiated signaling mechanisms?
- AAdenylyl cyclase
- BGuanylyl cyclase
- CPhospholipase C
- D All of the above
- ENone of the above
- AAdenylyl cyclase
122Which of the following is not involved in the activation of CREB?
- APKA
- BCaM kinase II
- CMAP kinase
- Dras
- E All of the above contribute to CREB activation
123Which of the following is the slowest chemical signaling process?
- AIon channel-mediated depolarization
- BG-protein-mediated modulation of ion channels
- CPhosphorylation of effector molecules by protein kinases
- DSynthesis of proteins after CREB activation
- ENone of the above; all have similar time courses
- AIon channel-mediated depolarization
124Dendritic spines
- Awere discovered with the invention of electron microscopy in the 1950s.
- Bserve as “electrical compartments” to ensure localized depolarization.
- C serve as “chemical compartments” to concentrate biochemical mechanisms.
- Dcollectively form a set of hard-wired permanent neural connections.
- Eare the sites of all excitatory and inhibitory synaptic transmission in the mammalian CNS.
- Awere discovered with the invention of electron microscopy in the 1950s.
125Which of the following does not contribute to maintaining low levels of calcium in resting nerve cells?
- A Voltage-gated calcium channels
- BThe plasma membrane calcium ATPase
- CThe smooth endoplasmic reticulum calcium ATPase
- DThe sodium–calcium exchanger
- EMitochondria
- A Voltage-gated calcium channels
126Which of the following statements about dendritic spines is false?
- AThey enable localized, transient increases in calcium.
- BThey slow the diffusion of IP3, but do not prevent it from leaving the spine.
- CThey are the sites of excitatory synapses in various parts of the CNS.
- DThey have a bulbous head connected to a dendritic shaft by a narrow neck.
- EThey usually contain just three proteins: NMDA receptors, mGluR receptors, and CaM kinase II.
- AThey enable localized, transient increases in calcium.
127Which of the following kinases is activated (in part) by a lipid?
- AProtein kinase A
- BProtein kinase C
- CProtein kinase G
- DCaM kinase II
- ECaM kinase IV
- AProtein kinase A
128Which of the following statements about cell signaling pathways is true?
- ACellular responses are always short-lived.
- BCellular responses are always long-lived.
- CSignaling is always initiated by membrane-bound receptors.
- DSignaling is always initiated by intracellular receptors.
- ENone of the above is true; all are false.
- ACellular responses are always short-lived.
129Which of the following is not integral to the functioning of protein kinases?
- A Hydrolysis of GTP prior to association of the regulatory and catalytic domains
- BReliance on functionally distinct roles of the different domains
- CBinding of one or more messengers to a regulatory domain
- DInhibition of a catalytic domain by a regulatory domain
- EActivation of a catalytic domain via a protein conformational change
130Listed below are the events that make up NGF-mediated growth of sensory neurons:
1. TrkA receptor self-phosphorylation
2. Translocation of activated kinases to the nucleus
3. NGF-induced dimerization of membrane receptors
4. TrkA induction of the ras signaling pathway- A1; 4; 3; 2
- B4; 1; 3; 2
- C3; 4; 1; 2
- D3; 1; 4; 2
- E1; 3; 4; 2
- A1; 4; 3; 2
131Which of the following is a second messenger whose activity is terminated by a phosphatase?
- ACalcium
- BCAMP
- CcGMP
- DInositol trisphosphate
- EDiacylglycerol
- ACalcium
132The acetylcholine receptor at the neuromuscular junction would best be described as a(n)
- Achannel-linked receptor.
- Benzyme-linked receptor.
- CG-protein-coupled receptor.
- Dnuclear receptor.
- Egap junction.
133Which of the following statements about protein kinase-based signaling is false?
- ASerine and threonine kinases are typically activated by second messengers.
- BTyrosine kinases are typically activated by extracellular signals.
- CEach protein kinase has just one specific target protein that it phosphorylates.
- DThe effects of protein kinases can be balanced by protein phosphatases.
- EThousands of protein kinases are expressed in the brain.
- ASerine and threonine kinases are typically activated by second messengers.
134Which of the following signaling pathways does not directly involve calcium?
- ARyanodine receptor
- BIP3 receptor
- CcGMP
- DPhospholipase C
- ECalmodulin
- ARyanodine receptor
135Which of the following types of chemical signaling acts over a small neural region encompassing a cluster of nerve cells?
- AEndocrine
- BExocrine
- CParacrine
- DSynaptic
- EEphaptic
136Which of the following was an invention (by Roger Tsien) that enabled the first precise spatial and temporal measurements of intracellular calcium dynamics?
- AVoltage clamp
- BFura-2
- CCalcium green
- DGFP
- EChannel rhodopsin
- AVoltage clamp
137Tyrosine hydroxylase is a substrate for which of the following protein kinases?
- APKA
- BPKC
- CCaM kinase II
- DMAP kinase
- E All of the above
138Which of the following statements about the LTD mechanism in cerebellar Purkinje cells is false?
- AAlternating activation of climbing fibers and parallel fibers is required to induce LTD.
- BThe firing of parallel fibers activates mGluR receptors and generates IP3.
- CClimbing fibers generate a large calcium signal in Purkinje cell dendrites.
- DBoth IP3 and calcium are required to activate the IP3 receptors and depress AMPA receptor activity.
- EThe strength of the parallel fiber synapses can be depressed for a long period of time.
139The protein ras
- Aregulates cell differentiation.
- Bis a monomeric, or small, G-protein.
- Cis named after the rat sarcoma tumor virus.
- DAll of the above
- ENone of the above
- Aregulates cell differentiation.
140In a signal transduction cascade using G-proteins and cAMP, which of the following is not a signal amplification step?
- AActivation of G-proteins by an activated receptor
- B Activation of adenylyl cyclase molecules by G-proteins
- CCreation of cAMP molecules by adenylyl cyclase
- DPhosphorylation of target proteins by protein kinase A
- EAll of the above are steps in which amplification occurs.
- AActivation of G-proteins by an activated receptor
141In the context of neuropathological activity, the phenomenon of kindling refers to
- Asmall burns made in cortex by an electrical stimulating electrode.
- Bthe ability to induce LTP in the amygdala and other brain regions in live animals.
- Cthe ability of daily administration of a weak, low-amplitude train of electrical pulses to gradually evoke larger and larger behavioral responses.
- Dthe phenomenon whereby a single, strong electrical pulse can evoke a full-blown seizure.
- Echaotic patterns of neural activity resembling the flame of a candle.
- Asmall burns made in cortex by an electrical stimulating electrode.
142Which of the following was not an important factor in the discoveries made from the genetic analysis of learning and memory in fruit flies?
- AThe ability to behaviorally assay large numbers of animals
- BDevelopment of an assay that was sensitive to learning and memory deficits
- CThe ability to discriminate learning deficits from sensory and motor deficits
- DDevelopment of novel apparatus to perform the behavioral assays
- E All of the above were important.
- AThe ability to behaviorally assay large numbers of animals
143Which of the following mechanisms 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?
- AActivation of G-protein-coupled receptors by serotonin
- B Phosphorylation of CREB
- CActivation of adenylyl cyclase
- DActivation of protein kinase A
- EDecreased opening of potassium channels during presynaptic action potentials
- AActivation of G-protein-coupled receptors by serotonin
144Cerebellar LTD depends upon
- Asynergistic actions of calcium and IP3 on internal calcium release channels.
- Bsynergistic actions of sodium and IP3 on internal calcium release channels.
- Cactivation of AMPA receptors by voltage-gated ion channels.
- Dbinding of IP3 to clathrin to activate endocytosis.
- Ecalcium-dependent insertion of GABA receptors into the postsynaptic membrane.
145Which of the following statements about the plasticity of synapses in the mammalian CNS is false?
- AThe hallmark of both short-term and long-term synaptic plasticity is that they always increase the strength of synaptic connections.
- BThe efficacy of synapses can be adjusted by modulating the amount of neurotransmitter that is released.
- CCalcium ions play a central role in at least some forms of synaptic plasticity.
- DChanges in synaptic efficacy can occur over time scales ranging from milliseconds to years.
- EA variety of molecular mechanisms are involved in the different forms of synaptic plasticity.
146Learning and memory processes in the fruit fly Drosophila show striking molecular overlap with analogous processes in Aplysia, in terms of their using all of the following except
- Aphosphodiesterase.
- Badenylyl cyclase.
- Cadenylyl cyclase activating pathways.
- D allosteric modulation of GABA receptors.
- ECREB gene regulation.
- Aphosphodiesterase.
147Which of the following mechanisms used in hippocampal LTD is not part of the hippocampal LTP mechanism?
- AHistory-dependent modification of synaptic efficacy
- BNMDA receptor activation
- CCalcium influx
- D Calcium-dependent activation of protein phosphatases
- EAll of the above are used in both LTD and LTP.
- AHistory-dependent modification of synaptic efficacy
148Which of the following observations would demonstrate the spike timing-dependent plasticity of synapses?
- AWhether or not LTP occurs depends on the specific temporal pattern of action potentials.
- BLTP occurs whenever an action potential precedes an EPSP.
- CLTD occurs whenever an action potential follows an EPSP.
- DSwitching 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.
- EA rhythmic pattern of spike–EPSP–spike–EPSP, at 40 ms intervals, produces maximal LTP.
- AWhether or not LTP occurs depends on the specific temporal pattern of action potentials.
149Which of the following is not part of the hippocampus?
- AArea CA1
- BArea CA3
- CArea MT
- DDentate gyrus
- ENone of the above; all are part of the hippocampus
- AArea CA1
150After firing a short burst of action potentials in an axon, researchers observe a larger EPSP in the postsynaptic cell, and this effect seems to last a few tens of milliseconds. This is most likely due to the presynaptic terminal having
- A extra calcium.
- Blowered calcium.
- Cextra sodium.
- Dreduced sodium.
- Eextra magnesium.
151Which of the following statements about LTP is false?
- ALTP involves an enhancement in synaptic efficacy that can last for hours, days, weeks or even longer.
- BIf one synapse (A) is very strongly stimulated (sufficient to cause LTP), and another nearby synapse (B) on the same dendrite is weakly stimulated at the same time, then the second synapse (B) will also show LTP.
- CIf 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.
- DThe requirement for coincident pre- and post-synaptic activity was predicted by Donald Hebb in 1949.
- EHippocampal LTP was first reported by Bliss and Lomo about 1970.
- ALTP involves an enhancement in synaptic efficacy that can last for hours, days, weeks or even longer.
152Which statement about the mechanisms underlying hippocampal LTP induction is false?
- AAn influx of calcium triggers two or more intracellular processes in the postsynaptic dendritic spine.
- BCalcium may trigger the release of a retrograde messenger that enhances transmitter release from the presynaptic terminal.
- CCalcium may activate CaM kinase II in such a way that it switches to a long-term “on” state.
- DCalcium may activate a signaling cascade that causes the insertion of glutamate receptors into the postsynaptic membrane.
- ECalcium decreases a resting leak current of sodium so that the postsynaptic cell is closer to threshold and therefore fires more easily.
- AAn influx of calcium triggers two or more intracellular processes in the postsynaptic dendritic spine.
153Which of the following would not be a plausible mechanism explaining synaptic depression?
- AInhibition of presynaptic calcium channels
- BActivation of presynaptic potassium channels
- CDepletion of docked synaptic vesicles in the presynaptic terminal
- DDelayed replenishment of vesicles to the reserve pool
- E Enhancement of presynaptic sodium currents
- AInhibition of presynaptic calcium channels
154The key aspect of receptor gating in the associative induction of hippocampal LTP is that
- Aall glutamate receptors open automatically whenever glutamate is in the synaptic cleft.
- Bthe NMDA receptor acts as a molecular coincidence detector
- Cthe AMPA receptor allows calcium into the cell only after the NMDA receptor is activated.
- Dboth the NMDA and AMPA channels must be open in order for the cell to depolarize.
- EAll of the above are key aspects of LTP induction.
- Aall glutamate receptors open automatically whenever glutamate is in the synaptic cleft.
155Firing an action potential in an axon initially causes a 10 mV depolarization (EPSP) in a postsynaptic neuron, but after giving a certain stimulus to the axon, firing it causes an 8 mV depolarization, after each action potential. This phenomenon is called
- Aenhancement.
- Bdepression
- Cfacilitation.
- Daugmentation
- Epotentiation.
- Aenhancement.
156The targets of the phosphatases activated during hippocampal LTD are
- Avoltage-gated ion channels.
- Bligand-gated ion channels.
- Csynaptic vesicle regulatory proteins.
- Dpostsynaptic signaling pathways.
- Eunknown
- Avoltage-gated ion channels.
157Which of the following is the band of hippocampal dendrites that receives inputs from the Schaeffer collaterals?
- AMossy fibers
- BPerforant path
- C Stratum radiatum
- DCA1 region
- ECA3 region
- AMossy fibers
158Which of the following statements about long-term synaptic plasticity in Aplysia is false?
- AThe efficacy of transmission at many synapses depends upon their history of synaptic activity.
- BThe tracking of long-term changes in synaptic efficacy is difficult in mammalian systems because of the complexity of mammalian brains.
- CThe gill withdrawal reflex in Aplysia can be enhanced by pairing a noxious stimulus with a mild touch.
- DAssociative learning in the Aplysia gill withdrawal reflex is relatively independent of the timing or the order in which different stimuli are applied.
- EGill withdrawal behavior in Aplysia can be altered for days or weeks by means of repeated pairings of shocks and touches.
- AThe efficacy of transmission at many synapses depends upon their history of synaptic activity.
159The type of receptor that is critical for the induction of hippocampal LTP, by virtue of its admitting calcium into a dendritic spine, is called a(n)
- AAMPA receptor.
- BNMDA receptor
- Cglycine receptor.
- Dcholinergic GPCR.
- Enoradrenergic GPCR.
- AAMPA receptor.
160Silent synapses are “silent” because they
- Ahave no presynaptic terminal.
- Bhave AMPA receptors but no NMDA receptors.
- Chave NMDA receptors but no AMPA receptors.
- Dlack voltage-gated sodium channels.
- Eare continuously inhibited and so cannot be activated.
- Ahave no presynaptic terminal.
Informações
- Descrição
- BioPsych Final
- Autor
- sukialmeida
- Idioma
- English
- Visualizações
- 194
- Histórico
- Criado em 26 abr 2015 · atualizado em 6 abr 2018
- Etiquetas
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