Question 1

While characterizing the activities of several neurons,you find a neuron with the following properties: (1)When stimulated,the neuron fails to release neurotransmitters into the synaptic cleft.
(2)Microinjection of calcium ions calcium ions has no effect on the neuron.(In other neurons such microinjection stimulates the t-SNARE and v-SNARE complex interaction that promotes neurotransmitter secretion.)
The abnormality in this neuron is most likely associated with the function of

Accepted Answer

A) the vesicle membranes. 
B) acetylcholinesterase. 
C) synaptotagmin. 
D) GABA receptors. 
E) gap junctions.

Question 2

Although they are smaller than K+,Na+ ions fail to pass through K+ channels because Na+

Accepted Answer

A) is repulsed by positively charged amino acids at the mouth of the channel. 
B) is too small to interact with oxygen atoms in amino acids on all sides of the channel and therefore does not completely lose its waters of hydration. 
C) is always transported complexes to Cl−. 
D) is always transported in a complex with two other Na+ ions. 
E) is attracted by other Na+ ions,which are at higher concentration outside than inside the cell.

Question 3

The intracellular stimulus for secretion of neurotransmitters into the synaptic cleft is an increase in

Accepted Answer

A) potassium ion levels. 
B) chloride ion levels. 
C) sodium ion levels. 
D) calcium ion levels. 
E) acetylcholine levels.

Question 4

What happens to neurons in the approach known as optogenetics?

Accepted Answer

A) Mutations to ion channel proteins are corrected. 
B) The neurons are made to express light-sensitive ion channels. 
C) Neurotransmitter stores are depleted. 
D) Fusion of neurotransmitter vesicles to the presynaptic membrane is blocked. 
E) Leakage of cytoplasmic polyanions is blocked.

Question 5

Tricyclic antidepressants,such as imipramine hydrochloride,have been prescribed for treatment of ADHD (attention deficit hyperactivity disorder)to enhance neural circuit activity because they affect the reuptake of excitatory neurotransmitters.Predict the effect of such drugs on the postsynaptic neuron and explain your rationale.

Accepted Answer

The answer of Tricyclic antidepressants,such as imipramine hydrochloride,have been prescribed...

Question 6

A nerve cell ________ involves a temporary depolarization and repolarization of the cell membrane.

Accepted Answer

The answer of A nerve cell ________ involves a temporary...

Question 7

________ is an autoimmune disease characterized by the presence of antibodies that bind to and block acetylcholine receptors.

Accepted Answer

The answer of ________ is an autoimmune disease characterized by...

Question 8

Each of the following is a voltage-gated Na+ channel property except

Accepted Answer

A) opens rapidly when stimulated. 
B) closes rapidly in absence of stimulus. 
C) opens to a variable extent depending on how much the stimulus voltage exceeds the threshold voltage. 
D) has a voltage sensor helix that controls channel gating. 
E) can be inactivated by the inactivating particle part of the channel protein.

Question 9

-The parts of the graph indicated between points C and E represent

Accepted Answer

A) depolarization. 
B) hyperpolarization. 
C) the absolute refractory period. 
D) repolarization. 
E) sodium channel activity.

Question 10

________ carry a signal across the synapse between two adjacent nerve cells.

Accepted Answer

The answer of ________ carry a signal across the synapse...

Question 11

The resting potential of a particular nerve cell is −66 mV.Depolarization of the neuron membrane will shift the membrane potential to

Accepted Answer

A) −90 mV. 
B) −75 mV. 
C) 0 mV. 
D) +45 mV. 
E) +66 mV.

Question 12

How many neuronal connections are there in the human brain?

Accepted Answer

A) millions 
B) 1 billion 
C) 10 billion 
D) 100 billion 
E) trillions

Question 13

Which of the following interferes with the reuptake of neurotransmitters?

Accepted Answer

A) Valium 
B) Librium 
C) Botox 
D) Prozac 
E) curare

Question 14

Which neurotransmitter is not an amino acid derivative?

Accepted Answer

A) GABA 
B) serotonin 
C) histamine 
D) dopamine 
E) glutamate

Question 15

Which of the following is a disease specifically caused by an autoimmune response against acetylcholine receptors?

Accepted Answer

A) ataxia 
B) myasthenia gravis 
C) multiple sclerosis 
D) tetanus 
E) botulism

Question 16

You have added a specific amount of excitatory neurotransmitter mixed with a 6× higher concentration of an inhibitory neurotransmitter to a synaptic cleft.You expect that the postsynaptic neuron will

Accepted Answer

A) produce 6× its normal number of action potentials. 
B) produce 6× its normal number of negative action potentials. 
C) show a net hyperpolarization as a result of neuronal integration. 
D) show a net depolarization as a result of neuronal integration. 
E) not respond to either signal.

Question 17

A drug that specifically inhibits voltage-gated calcium channels would most directly inhibit

Accepted Answer

A) depolarization of nerve cell membranes. 
B) repolarization after depolarization of nerve cell membranes. 
C) hyperpolarization of nerve cell membranes. 
D) presynaptic neurotransmitter release. 
E) postsynaptic receptor signal response.

Question 18

Synaptic vesicles are synthesized in the nerve ________.

Accepted Answer

The answer of Synaptic vesicles are synthesized in the nerve...

Question 19

Each of the following contributes to the unidirectional propagation of nerve signals except

Accepted Answer

A) dendrites only receive signals. 
B) presynaptic neurotransmitter secretion is separated from postsynaptic receptors. 
C) neuron membranes have a refractory period following generation of an action potential. 
D) ion channels are oriented to transport ions only into the neuron. 
E) action potentials initiate the hillock and propagate only down the axon.

Question 20

An example of a generally inhibitory neurotransmitter is

Accepted Answer

A) acetylcholine. 
B) glutamate. 
C) dopamine. 
D) GABA. 
E) serotonin.

Exam 22: Signal Transduction Mechanisms: Ielectrical and Synaptic Signaling in Neurons

Although they are smaller than K⁺,Na⁺ ions fail to pass through K⁺channels because Na⁺