Quiz lecture 2

Question 1

Match the ion channel action with its resulting change in membrane potential:

a. entry of a negative ion; hyperpolarization
b. entry of a positive ion; hyperpolarization
c. exit of a positive ion; depolarization
d. exit of a negative ion; hyperpolarization
e. inactivation of sodium-potassium transporters; depolarization

Answer 1

a. entry of a negative ion; hyperpolarization

Question 2

An EPSP will be produced when a ligand

a. opens a sodium channel.
b. closes a sodium channel.
c. opens a potassium channel.
d. closes a calcium channel.
e. closes a chloride channel.

Answer 2

a. opens a sodium channel.

Question 3

Inactivation of the sodium channels by a drug such as TTX would be expected to

a. prevent further action potentials in that neuron membrane.
b. shorten the neuron refractory period.
c. increase the amplitude of the action potential.
d. increase the frequency of nerve cell firing.
e. B and D are correct.

Answer 3

a. prevent further action potentials in that neuron membrane.

Question 4

Ligands are chemicals that

a. detect the presence of neurotransmitters in the synaptic cleft.
b. surround synaptic vesicles and prevent the premature release of the neurotransmitter.
c. are found only at axodendritic synapses.
d. attach to binding sites.

Answer 4

d. attach to binding sites.

Question 5

All of the following statements about acetylcholine are true except

a. it was the first neurotransmitter to be discovered.
b. it is deactivated by choline acetyltransferase (ChAT) into its components, acetate and choline.
c. muscle movement is stimulated by its release.
d. once it is deactivated, choline is returned to the terminal buttons and recycled.

Answer 5

b. it is deactivated by choline acetyltransferase (ChAT) into its components, acetate and choline.

Question 6

A drug that mimics the effects of a neurotransmitter acts as a(n)

a. direct antagonist.
b. receptor blocker.
c. indirect ligand.
d. direct agonist.

Answer 6

d. direct agonist.

Question 7

Drugs that block or inhibit postsynaptic receptor effects are termed

a. Ligands.
b. exogenous.
c. antagonists.
d. indirect agonists.

Answer 7

c. antagonists.

Question 8

A placebo effect

a. varies with the strength of the drug.
b. has no role in neuroscience research.
c. can have physiological causes.
d. is always pleasurable.

Answer 8

c. can have physiological causes.

Question 9

Administering a molecule that is a precursor for the synthesis of a synaptic neurotransmitter would be expected to

a. reduce the availability of that neurotransmitter.
b. increase the rate of synthesis and release of that neurotransmitter.
c. alter the number of postsynaptic receptors.
d. act as an antagonist at autoreceptors.
e. dampen the activity of the synapse.

Answer 9

b. increase the rate of synthesis and release of that neurotransmitter.

Question 10

A drug that binds at a postsynaptic site different from that of the neurotransmitter and facilitates the opening of ion channels would be termed a(n)

a. indirect antagonist.
b. ligand.
c. direct synergist.
d. indirect agonist.
e. inducer.

Answer 10

d. indirect agonist.

Question 11

11. Infusion of low doses of ________will excite neurons
    a. GABA
    b. glycine
    c. lidocaine
    d. glutamate
    e. 6-hydroxydopamine

Answer 11

d. glutamate