Question 1

Why are chromaffin cells of the adrenal medulla a good model for studying vesicle release?

Accepted Answer

A)  Chromaffin cells release the same transmitter as the neuromuscular junction. 
B)  Chromaffin cells contain granules, which are organelles that are analogous to, and the same size as, synaptic vesicles. Therefore, studying granule release is the same as studying synaptic vesicle release. 
C)  Chromaffin cells contain granules, which are organelles that are analogous to, but much smaller, than synaptic vesicles. Exocytosis of these smaller granules is faster and therefore, easier to study. 
D)  Chromaffin cells contain granules, which are organelles that are analogous to, but much larger than, synaptic vesicles. Exocytosis of these larger granules is easier to study. 
E)  Chromaffin cells release transmitter in a nonquantal fashion, without the use of synaptic vesicles. 
A)  Chromaffin cells release the same transmitter as the neuromuscular junction. 
B)  Chromaffin cells contain granules, which are organelles that are analogous to, and the same size as, synaptic vesicles. Therefore, studying granule release is the same as studying synaptic vesicle release. 
C)  Chromaffin cells contain granules, which are organelles that are analogous to, but much smaller, than synaptic vesicles. Exocytosis of these smaller granules is faster and therefore, easier to study. 
D)  Chromaffin cells contain granules, which are organelles that are analogous to, but much larger than, synaptic vesicles. Exocytosis of these larger granules is easier to study. 
E)  Chromaffin cells release transmitter in a nonquantal fashion, without the use of synaptic vesicles.

Question 2

How does the actylcholine receptor antagonist curare affect mEPPs?

Accepted Answer

A)  Curare prolongs the time course of mEPPs. 
B)  Curare increases the amplitude of mEPPs. 
C)  Curare prolongs the time course and increases the amplitude of mEPPs. 
D)  Curare reduces the amplitude or blocks mEPPs. 
E)  Curare has no effect on mEPPs. 
A)  Curare prolongs the time course of mEPPs. 
B)  Curare increases the amplitude of mEPPs. 
C)  Curare prolongs the time course and increases the amplitude of mEPPs. 
D)  Curare reduces the amplitude or blocks mEPPs. 
E)  Curare has no effect on mEPPs.

Question 3

What is the reserve pool of vesicles?

Accepted Answer

A)  Vesicles that are only released during intense prolonged stimulation 
B)  Vesicles that result from recent endocytosis and are re-filled with transmitter 
C)  The first vesicles to be released upon stimulation 
D)  Vesicles that are not depleted rapidly by stimulation 
E)  Vesicles that are never released with action potential stimulation 
A)  Vesicles that are only released during intense prolonged stimulation 
B)  Vesicles that result from recent endocytosis and are re-filled with transmitter 
C)  The first vesicles to be released upon stimulation 
D)  Vesicles that are not depleted rapidly by stimulation 
E)  Vesicles that are never released with action potential stimulation

Question 4

How do calcium ions trigger synaptic vesicle exocytosis?

Accepted Answer

Calcium ions entering the nerve terminal

Question 5

What process at chemical synapses takes the most time and contributes the most to the synaptic delay?

Accepted Answer

A)  Diffusion of transmitter across the synaptic cleft 
B)  The transmitter release process in the nerve terminal 
C)  The binding of transmitter to postsynaptic ionotropic receptors 
D)  The opening of channels in postsynaptic ionotropic receptors 
E)  The opening of presynaptic calcium channels in response to an action potential 
A)  Diffusion of transmitter across the synaptic cleft 
B)  The transmitter release process in the nerve terminal 
C)  The binding of transmitter to postsynaptic ionotropic receptors 
D)  The opening of channels in postsynaptic ionotropic receptors 
E)  The opening of presynaptic calcium channels in response to an action potential

Question 6

What are the different forms of endocytosis?

Accepted Answer

A)  Kiss-and-run, ultra-slow endocytosis, and clathrin-mediated endocytosis 
B)  Kiss-and-run, bulk endocytosis, ultra-fast endocytosis, and clathrin-mediated endocytosis 
C)  Kiss-and-run, bulk endocytosis, ultra-slow endocytosis, and clathrin-mediated endocytosis 
D)  Bulk endocytosis, ultra-fast endocytosis, and clathrin-mediated endocytosis 
E)  Kiss-and-run, bulk endocytosis, ultra-fast endocytosis, ultra-slow endocytosis, and clathrin-mediated endocytosis 
A)  Kiss-and-run, ultra-slow endocytosis, and clathrin-mediated endocytosis 
B)  Kiss-and-run, bulk endocytosis, ultra-fast endocytosis, and clathrin-mediated endocytosis 
C)  Kiss-and-run, bulk endocytosis, ultra-slow endocytosis, and clathrin-mediated endocytosis 
D)  Bulk endocytosis, ultra-fast endocytosis, and clathrin-mediated endocytosis 
E)  Kiss-and-run, bulk endocytosis, ultra-fast endocytosis, ultra-slow endocytosis, and clathrin-mediated endocytosis

Question 7

Which of the following occurs at active zones?

Accepted Answer

A)  Synaptic protein translation 
B)  Mitochondrial generation of ATP 
C)  Neurotransmitter synthesis 
D)  Action potential generation 
E)  Vesicle exocytosis 
A)  Synaptic protein translation 
B)  Mitochondrial generation of ATP 
C)  Neurotransmitter synthesis 
D)  Action potential generation 
E)  Vesicle exocytosis

Question 8

What is the recycling pool of vesicles?

Accepted Answer

A)  Vesicles that are only released during intense prolonged stimulation 
B)  Vesicles that result from recent endocytosis and are re-filled with transmitter 
C)  The first vesicles to be released upon stimulation 
D)  Vesicles that are not depleted rapidly by stimulation 
E)  Vesicles that are never released with action potential stimulation 
A)  Vesicles that are only released during intense prolonged stimulation 
B)  Vesicles that result from recent endocytosis and are re-filled with transmitter 
C)  The first vesicles to be released upon stimulation 
D)  Vesicles that are not depleted rapidly by stimulation 
E)  Vesicles that are never released with action potential stimulation

Question 9

What is a synaptic ribbon?

Accepted Answer

A synaptic ribbon is an intracellular or

Question 10

Why does transmitter release continue to occur after blocking presynaptic sodium channels with the toxin TTX (which blocks the presynaptic action potential) and experimentally depolarizing the nerve terminal?

Accepted Answer

This result indicates that the normal fl

Question 11

Which is both necessary and sufficient to trigger chemical transmitter release from a presynaptic nerve terminal?

Accepted Answer

A)  A presynaptic action potential 
B)  An opening of presynaptic sodium channels 
C)  An opening of presynaptic potassium channels 
D)  An increase in presynaptic calcium concentration 
E)  Proton-dependent transport of transmitter into vesicles 
A)  A presynaptic action potential 
B)  An opening of presynaptic sodium channels 
C)  An opening of presynaptic potassium channels 
D)  An increase in presynaptic calcium concentration 
E)  Proton-dependent transport of transmitter into vesicles

Question 12

If one would like to use the voltage clamp technique to record presynaptic calcium currents from a nerve terminal, why are tetrodotoxin (TTX) and tetraethylammonium (TEA) used?

Accepted Answer

A)  TTX blocks potassium channels and TEA blocks sodium channels. 
B)  TTX blocks sodium channels and TEA blocks potassium channels. 
C)  TTX blocks calcium channels and TEA blocks potassium channels. 
D)  TTX blocks sodium channels and TEA blocks calcium channels. 
E)  TTX blocks sodium channels and TEA blocks chloride channels. 
A)  TTX blocks potassium channels and TEA blocks sodium channels. 
B)  TTX blocks sodium channels and TEA blocks potassium channels. 
C)  TTX blocks calcium channels and TEA blocks potassium channels. 
D)  TTX blocks sodium channels and TEA blocks calcium channels. 
E)  TTX blocks sodium channels and TEA blocks chloride channels.

Question 13

What is the role of Munc-13 in synaptic vesicle exocytosis?

Accepted Answer

The t-SNARE syntaxin is held in a closed

Question 14

When synaptic vesicles collapse into the plasma membrane, and then participate in endocytosis, they

Accepted Answer

A)  pull back into their lumen the soluble contents of the extracellular saline. 
B)  pull back selectively transmitter from the synaptic cleft. 
C)  do not pull anything back into the vesicle; they are empty. 
D)  pull back selectively the breakdown products of transmitter. 
E)  pull back acetylcholinesterase from the synaptic cleft. 
A)  pull back into their lumen the soluble contents of the extracellular saline. 
B)  pull back selectively transmitter from the synaptic cleft. 
C)  do not pull anything back into the vesicle; they are empty. 
D)  pull back selectively the breakdown products of transmitter. 
E)  pull back acetylcholinesterase from the synaptic cleft.

Question 15

What is the synaptic delay at a synapse that uses chemical transmitters at room temperature?

Accepted Answer

A)  100 milliseconds 
B)  10 milliseconds 
C)  0.5 milliseconds 
D)  10 microseconds 
E)  0.5 microseconds 
A)  100 milliseconds 
B)  10 milliseconds 
C)  0.5 milliseconds 
D)  10 microseconds 
E)  0.5 microseconds

Question 16

What is thought to significantly restrict the spread of calcium ions after they enter the nerve terminal through presynaptic calcium channels?

Accepted Answer

A)  The presynaptic calcium channel 
B)  Calcium buffers and binding proteins (chelators) 
C)  The activity of potassium channels 
D)  Calcium binding to synaptotagmin 
E)  The calcium concentration gradient across the nerve terminal membrane 
A)  The presynaptic calcium channel 
B)  Calcium buffers and binding proteins (chelators) 
C)  The activity of potassium channels 
D)  Calcium binding to synaptotagmin 
E)  The calcium concentration gradient across the nerve terminal membrane

Question 17

What explains why there is a threshold depolarization of about 45 mV above resting membrane potential before any transmitter release occurs?

Accepted Answer

A)  This is the magnitude of depolarization required to activate presynaptic voltage gated sodium channels. 
B)  This is the magnitude of depolarization required to activate presynaptic voltage gated potassium channels. 
C)  This is the magnitude of depolarization required to activate a presynaptic action potential. 
D)  This is the magnitude of depolarization required to activate presynaptic voltage-gated calcium channels. 
E)  This is the magnitude of depolarization required to activate a postsynaptic action potential. 
A)  This is the magnitude of depolarization required to activate presynaptic voltage gated sodium channels. 
B)  This is the magnitude of depolarization required to activate presynaptic voltage gated potassium channels. 
C)  This is the magnitude of depolarization required to activate a presynaptic action potential. 
D)  This is the magnitude of depolarization required to activate presynaptic voltage-gated calcium channels. 
E)  This is the magnitude of depolarization required to activate a postsynaptic action potential.

Question 18

When applying statistical methods to analyze transmitter release, what does the term "p" represent in the binomial theory?

Accepted Answer

A)  The probability of transmitter release from the whole nerve terminal 
B)  The probability of receptors binding transmitter 
C)  The probability of transmitter release from each release site in one nerve terminal 
D)  The probability of calcium channel opening during an action potential 
E)  The probability of action potential generation 
A)  The probability of transmitter release from the whole nerve terminal 
B)  The probability of receptors binding transmitter 
C)  The probability of transmitter release from each release site in one nerve terminal 
D)  The probability of calcium channel opening during an action potential 
E)  The probability of action potential generation

Question 19

If an experimenter used the voltage clamp technique to change the presynaptic voltage from -70 mV to +60 mV, what would happen to voltage-gated calcium channels?

Accepted Answer

A)  Voltage-gated calcium channels would open and pass a large amount of inward current. 
B)  Voltage-gated calcium channels would open and pass a large amount of outward current. 
C)  Voltage-gated calcium channels would open but no current would pass through the open channel. 
D)  Voltage-gated calcium channels would not open and therefore, not pass any current. 
E)  Voltage-gated calcium channels would not open but a large amount of inward current would pass across the membrane. 
A)  Voltage-gated calcium channels would open and pass a large amount of inward current. 
B)  Voltage-gated calcium channels would open and pass a large amount of outward current. 
C)  Voltage-gated calcium channels would open but no current would pass through the open channel. 
D)  Voltage-gated calcium channels would not open and therefore, not pass any current. 
E)  Voltage-gated calcium channels would not open but a large amount of inward current would pass across the membrane.

Question 20

What are the three distinct synaptic vesicle pools in the nerve terminal?

Accepted Answer

A)  Docked pool, primed pool, and reserve pool 
B)  Readily releasable pool, docked pool, and reserve pool 
C)  Extra pool, recycling pool, and reserve pool 
D)  Extra pool, readily releasable pool, and reserve pool 
E)  Readily releasable pool, recycling pool, and reserve pool 
A)  Docked pool, primed pool, and reserve pool 
B)  Readily releasable pool, docked pool, and reserve pool 
C)  Extra pool, recycling pool, and reserve pool 
D)  Extra pool, readily releasable pool, and reserve pool 
E)  Readily releasable pool, recycling pool, and reserve pool

Exam 13: Release of Neurotransmitters

Why are chromaffin cells of the adrenal medulla a good model for studying vesicle release?

How does the actylcholine receptor antagonist curare affect mEPPs?

What is the reserve pool of vesicles?

How do calcium ions trigger synaptic vesicle exocytosis?

What process at chemical synapses takes the most time and contributes the most to the synaptic delay?

What are the different forms of endocytosis?

Which of the following occurs at active zones?

What is the recycling pool of vesicles?

What is a synaptic ribbon?

Why does transmitter release continue to occur after blocking presynaptic sodium channels with the toxin TTX (which blocks the presynaptic action potential) and experimentally depolarizing the nerve terminal?

Which is both necessary and sufficient to trigger chemical transmitter release from a presynaptic nerve terminal?

If one would like to use the voltage clamp technique to record presynaptic calcium currents from a nerve terminal, why are tetrodotoxin (TTX) and tetraethylammonium (TEA) used?

What is the role of Munc-13 in synaptic vesicle exocytosis?

When synaptic vesicles collapse into the plasma membrane, and then participate in endocytosis, they

What is the synaptic delay at a synapse that uses chemical transmitters at room temperature?

What is thought to significantly restrict the spread of calcium ions after they enter the nerve terminal through presynaptic calcium channels?

What explains why there is a threshold depolarization of about 45 mV above resting membrane potential before any transmitter release occurs?

When applying statistical methods to analyze transmitter release, what does the term "p" represent in the binomial theory?

If an experimenter used the voltage clamp technique to change the presynaptic voltage from -70 mV to +60 mV, what would happen to voltage-gated calcium channels?

What are the three distinct synaptic vesicle pools in the nerve terminal?

Principles of Signaling and Organization

Signaling in the Visual System

Functional Architecture of the Visual Cortex

Ion Channels and Signaling

Structure of Ion Channels

Ionic Basis of the Resting Potential

Ionic Basis of the Action Potential

Electrical Signaling in Neurons

Ion Transport Across Cell Membranes

Properties and Functions of Neuroglial Cells

Mechanisms of Direct Synaptic Transmission

Indirect Mechanisms of Synaptic Transmission

Neurotransmitters in the Central Nervous System

Transmitter Synthesis, Storage, Transport, and Inactivation

Synaptic Plasticity

The Molecular and Cellular Biology of Synaptic Plasticity

Mechanisms of Extrasynaptic Communication

Autonomic Nervous System

Walking, Flying, and Swimming: Cellular Mechanisms of Sensorimotor Behavior in Invertebrates

Sensory Transduction

Transduction and Transmission in the Retina

Touch, Pain, and Texture Sensation

Auditory and Vestibular Sensation

Constructing Perception

Initiation and Control of Coordinated Muscular Movements

Development of the Nervous System

Critical Periods in Sensory Systems

Regeneration and Repair of Synaptic Connections After Injury

Appendix

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