Question 1

An inhibitory postsynaptic potential (IPSP) occurs when

Accepted Answer

A)  the ligand-gated ion channels with a reversal potential that is more negative than membrane potential open in the postsynaptic membrane in response to transmitter binding. 
B)  the ligand-gated ion channels with a reversal potential that is more positive than membrane potential open in the postsynaptic membrane in response to transmitter binding. 
C)  metabotropic receptors are activated by transmitter binding. 
D)  voltage-gated ion channels open during an action potential. 
E)  the ligand-gated ion channels without a reversal potential open in the postsynaptic membrane in response to transmitter binding. 
A)  the ligand-gated ion channels with a reversal potential that is more negative than membrane potential open in the postsynaptic membrane in response to transmitter binding. 
B)  the ligand-gated ion channels with a reversal potential that is more positive than membrane potential open in the postsynaptic membrane in response to transmitter binding. 
C)  metabotropic receptors are activated by transmitter binding. 
D)  voltage-gated ion channels open during an action potential. 
E)  the ligand-gated ion channels without a reversal potential open in the postsynaptic membrane in response to transmitter binding.

Question 2

What determines the coupling ratio between electrically couple neurons?

Accepted Answer

Electrical coupling between neurons depe

Question 3

Which two synaptic specializations are present at neuromuscular synapses, but not at CNS synapses?

Accepted Answer

A)  Postjunctional folds and Schwann cells 
B)  Synaptic vesicles and active zones 
C)  Glial cell wrapping and mitochondria 
D)  Postjunctional folds and mitochondria 
E)  Postjunctional folds and active zones 
A)  Postjunctional folds and Schwann cells 
B)  Synaptic vesicles and active zones 
C)  Glial cell wrapping and mitochondria 
D)  Postjunctional folds and mitochondria 
E)  Postjunctional folds and active zones

Question 4

In embryonic neurons, activation of ionotropic GABA or glycine receptors results in

Accepted Answer

A)  inward movement of chloride, which leads to hyperpolarization. 
B)  outward movement of chloride, which leads to hyperpolarization. 
C)  inward movement of chloride, which leads to depolarization. 
D)  outward movement of chloride, which leads to depolarization. 
E)  no net movement of chloride, which does not change membrane potential. 
A)  inward movement of chloride, which leads to hyperpolarization. 
B)  outward movement of chloride, which leads to hyperpolarization. 
C)  inward movement of chloride, which leads to depolarization. 
D)  outward movement of chloride, which leads to depolarization. 
E)  no net movement of chloride, which does not change membrane potential.

Question 5

How does acetylcholine binding to nicotinic receptors alter the permeability of the muscle membrane?

Accepted Answer

A)  The permeability of the postsynaptic membrane is increased to sodium, potassium, and calcium, but not to chloride. 
B)  The permeability of the postsynaptic membrane is increased to sodium, but not to potassium, calcium, and chloride. 
C)  The permeability of the postsynaptic membrane is increased to sodium, potassium, calcium, and chloride. 
D)  The permeability of the postsynaptic membrane is increased to potassium, but not to sodium, calcium, and chloride. 
E)  The permeability of the postsynaptic membrane is increased to calcium but not to sodium, potassium, and chloride. 
A)  The permeability of the postsynaptic membrane is increased to sodium, potassium, and calcium, but not to chloride. 
B)  The permeability of the postsynaptic membrane is increased to sodium, but not to potassium, calcium, and chloride. 
C)  The permeability of the postsynaptic membrane is increased to sodium, potassium, calcium, and chloride. 
D)  The permeability of the postsynaptic membrane is increased to potassium, but not to sodium, calcium, and chloride. 
E)  The permeability of the postsynaptic membrane is increased to calcium but not to sodium, potassium, and chloride.

Question 6

What is a competitive antagonist?

Accepted Answer

A)  An inhibitor ligand for a receptor that shares its binding site with the natural activating ligand 
B)  An agonist ligand for a receptor that shares its binding site with the natural activating ligand 
C)  An inhibitor ligand for a receptor that does not affect the natural activating ligand's ability to bind the receptor 
D)  An agonist ligand for a receptor that does not affect the natural activating ligand's ability to bind the receptor 
E)  A receptor ligand that binds to a part of a receptor that is not involved in natural ligand binding 
A)  An inhibitor ligand for a receptor that shares its binding site with the natural activating ligand 
B)  An agonist ligand for a receptor that shares its binding site with the natural activating ligand 
C)  An inhibitor ligand for a receptor that does not affect the natural activating ligand's ability to bind the receptor 
D)  An agonist ligand for a receptor that does not affect the natural activating ligand's ability to bind the receptor 
E)  A receptor ligand that binds to a part of a receptor that is not involved in natural ligand binding

Question 7

Why is electrical transmission faster than chemical transmission?

Accepted Answer

The 1 millisecond synaptic delay at a ch

Question 8

What are the three types of ionotropic glutamate receptors?

Accepted Answer

A)  Nicotinic, muscarinic, and kainate 
B)  Kainate, AMPA, and nicotinic 
C)  AMPA, NMDA, and nicotinic 
D)  Kainate, AMPA, and NMDA 
E)  Kainate, NMDA, and nicotinic 
A)  Nicotinic, muscarinic, and kainate 
B)  Kainate, AMPA, and nicotinic 
C)  AMPA, NMDA, and nicotinic 
D)  Kainate, AMPA, and NMDA 
E)  Kainate, NMDA, and nicotinic

Question 9

If one impales a neuron with two different intracellular microelectrodes, one to measure membrane potential and a second to pass brief hyperpolarizing current pulses into the cell, why does the size of the measured changes in membrane potential caused by the current pulses decrease when transmitter binds to an ionotropic receptor?

Accepted Answer

A)  The ionotropic receptor inhibits a voltage-gated sodium channel. 
B)  The ionotropic receptor inhibits a voltage-gated potassium channel. 
C)  The input resistance of the cell does not change when ionotropic receptor channels open. 
D)  The input resistance of the cell decreases when ionotropic receptor channels open. 
E)  The input resistance of the cell increases when ionotropic receptor channels open. 
A)  The ionotropic receptor inhibits a voltage-gated sodium channel. 
B)  The ionotropic receptor inhibits a voltage-gated potassium channel. 
C)  The input resistance of the cell does not change when ionotropic receptor channels open. 
D)  The input resistance of the cell decreases when ionotropic receptor channels open. 
E)  The input resistance of the cell increases when ionotropic receptor channels open.

Question 10

In the late 1800s, explain why the hypothesis that neurons in the brain communicated with one another by chemical transmitter release was not generally accepted.

Accepted Answer

The idea of chemicals being used to comm

Question 11

If two postsynaptic neurons both receive the same synaptic current, but neuron 1 has a much lower resting conductance than neuron 2, which neuron will experience a larger change in membrane potential cause by the synaptic current, and why?

Accepted Answer

Neuron 1 will experience a larger change

Question 12

Why does the plant alkaloid nicotine cause skeletal muscle contraction?

Accepted Answer

A)  Nicotine causes presynaptic action potentials. 
B)  Nicotine blocks postsynaptic nicotinic acetylcholine receptors. 
C)  Nicotine is an agonist at postsynaptic muscarinic acetylcholine receptors. 
D)  Nicotine is an agonist at postsynaptic nicotinic acetylcholine receptors. 
E)  Nicotine increases presynaptic calcium channel function, increasing transmitter release. 
A)  Nicotine causes presynaptic action potentials. 
B)  Nicotine blocks postsynaptic nicotinic acetylcholine receptors. 
C)  Nicotine is an agonist at postsynaptic muscarinic acetylcholine receptors. 
D)  Nicotine is an agonist at postsynaptic nicotinic acetylcholine receptors. 
E)  Nicotine increases presynaptic calcium channel function, increasing transmitter release.

Question 13

NMDA and AMPA subtypes of glutamate receptors are differentially regulated during synaptic plasticity, with AMPA receptors moving into or out of the postsynaptic density to alter the strength of chemical transmission. Explain how these two types of receptors are localized to postsynaptic sites of transmitter release and how these localization mechanisms might explain these differences in receptor movement.

Accepted Answer

NMDA-type glutamate receptors bind to pr

Question 14

What are the advantages of electrical transmission?

Accepted Answer

(1) Electrical synapses are more reliabl

Question 15

What is responsible for the time course of decay of the endplate current recorded at the neuromuscular junction?

Accepted Answer

A)  The time that acetylcholine is bound to the acetylcholine receptor. 
B)  The mean open time of the presynaptic calcium channel that triggers acetylcholine release. 
C)  The time course of synaptic vesicle endocytosis at the presynaptic nerve terminal. 
D)  The mean open time of the acetylcholine receptor channel. 
E)  The mean open time of the postsynaptic voltage-gated sodium channel. 
A)  The time that acetylcholine is bound to the acetylcholine receptor. 
B)  The mean open time of the presynaptic calcium channel that triggers acetylcholine release. 
C)  The time course of synaptic vesicle endocytosis at the presynaptic nerve terminal. 
D)  The mean open time of the acetylcholine receptor channel. 
E)  The mean open time of the postsynaptic voltage-gated sodium channel.

Question 16

Dendritic spines are commonly a site for

Accepted Answer

A)  both excitatory and inhibitory synaptic transmission. 
B)  inhibitory synaptic transmission. 
C)  excitatory synaptic transmission. 
D)  storage of transmitter molecules. 
E)  active zones. 
A)  both excitatory and inhibitory synaptic transmission. 
B)  inhibitory synaptic transmission. 
C)  excitatory synaptic transmission. 
D)  storage of transmitter molecules. 
E)  active zones.

Question 17

When electrical synapses are found in the adult CNS, what have they been shown to useful for?

Accepted Answer

Here are two examples. In cortex, electr

Question 18

How are acetylcholine receptors distributed along the muscle membrane?

Accepted Answer

A)  They are at a uniform density all along the muscle membrane. 
B)  They are distributed in a gradual gradient that increases density gradually with distance away from the NMJ. 
C)  They are distributed in a gradual gradient that decreases density gradually with distance away from the NMJ. 
D)  They are highly concentrated directly under the presynaptic terminal at the NMJ. 
E)  There are no acetylcholine receptors on muscle membrane, only on the nerve terminal at the NMJ. 
A)  They are at a uniform density all along the muscle membrane. 
B)  They are distributed in a gradual gradient that increases density gradually with distance away from the NMJ. 
C)  They are distributed in a gradual gradient that decreases density gradually with distance away from the NMJ. 
D)  They are highly concentrated directly under the presynaptic terminal at the NMJ. 
E)  There are no acetylcholine receptors on muscle membrane, only on the nerve terminal at the NMJ.

Question 19

Explain the voltage-sensitivity of the NMDA type of ionotropic glutamate receptors.

Accepted Answer

At resting membrane potential, the NMDA

Exam 11: Mechanisms of Direct Synaptic Transmission

An inhibitory postsynaptic potential (IPSP) occurs when

What determines the coupling ratio between electrically couple neurons?

Which two synaptic specializations are present at neuromuscular synapses, but not at CNS synapses?

In embryonic neurons, activation of ionotropic GABA or glycine receptors results in

How does acetylcholine binding to nicotinic receptors alter the permeability of the muscle membrane?

What is a competitive antagonist?

Why is electrical transmission faster than chemical transmission?

What are the three types of ionotropic glutamate receptors?

In the late 1800s, explain why the hypothesis that neurons in the brain communicated with one another by chemical transmitter release was not generally accepted.

If two postsynaptic neurons both receive the same synaptic current, but neuron 1 has a much lower resting conductance than neuron 2, which neuron will experience a larger change in membrane potential cause by the synaptic current, and why?

Why does the plant alkaloid nicotine cause skeletal muscle contraction?

What are the advantages of electrical transmission?

What is responsible for the time course of decay of the endplate current recorded at the neuromuscular junction?

Dendritic spines are commonly a site for

When electrical synapses are found in the adult CNS, what have they been shown to useful for?

How are acetylcholine receptors distributed along the muscle membrane?

Explain the voltage-sensitivity of the NMDA type of ionotropic glutamate receptors.

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

Indirect Mechanisms of Synaptic Transmission

Release of Neurotransmitters

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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