Univ. of Illinois, Urbana-Champaign
Bio/Neuro 303
Chapter 7 - Study Questions
209. At chemical synapses, the ion thought to be necessary inside the
presynaptic cell to facilitate the release of transmitter is
a. Na+.
b. Ca2+.
c. K+.
d. Cl-.
210. One important role of calcium ions at a chemical synapse is to
a. act as a transmitter substance.
b. facilitate the binding of the transmitter substance with receptor
molecules in the post-synaptic membrane.
c. aid in the inactivation of the transmitter.
d. facilitate the release of transmitter from the pre-synaptic terminal.
211. In chemical synaptic transmission, the Ca2+ that is necessary for release
of the transmitter substance
a. is already present in the presynaptic cell as free Ca2+.
b. is released by the AP from internal stores of bound Ca2+.
c. enters the presynaptic cell from the extracellular fluid.
d. comes from the synaptic vesicles themselves.
212. The protein that has been shown to form a cage-like barrier around clear
synaptic vesicles is known as
a. synapsin I.
b. kinesin.
c. tubulin.
d. kinysin I.
213. Synapsin I is the protein that
a. forms microtubules in neurons.
b. forms a barrier around synaptic vesicles.
c. acts to move particles in the anterograde direction along the length of
an axon during axoplasmic transport.
d. is part of the presynaptic membrane responsible for releasing
transmitter substance.
214. Synapsin-I is a protein that
a. is involved in anterograde axoplasmic transport of synaptic vesicles.
b. is involved in retrograde axoplasmic transport of synaptic vesicles.
c. is involved in binding synaptic vesicles to the presynaptic
cytoskeleton.
d. is part of the postsynaptic membrane responsible for stabilizing the
synapse.
215. The individuals largely responsible for demonstrating that transmitter
release could be quantal were
a. Hodgkin and Huxley.
b. Hodgkin and Katz.
c. Katz and Miledi.
d. Eccles and Miledi.
216. The person(s) largely responsible for describing the quantal nature of
neuromuscular transmission was (were)
a. Ochs.
b. Golgi.
c. Katz & Miledi.
d. Eccles.
217. The vesicular hypothesis of synaptic transmission states that
a. the presence of vesicles in an electron micrograph of nerve cells
defines the presence of a synapse.
b. vesicles are manufactured in the soma and transported to synapses by
axoplasmic transport.
c. vesicles are the site of synthesis of transmitter substance.
d. transmitter is packaged in the vesicles and released quantally from
them into the synaptic cleft.
218. In the vesicular hypothesis of synaptic transmission, the ______ in discrete
particles called vesicles.
a. electrical charges associated with the action potential are thought to
be packaged
b. electrical charges associated with the post-synaptic potential are
thought to be packaged
c. transmitter substance is thought to be packaged
d. calcium ions are thought to enter the pre-synaptic cell
219. Miniature end plate potentials (mepps) are
a. the small changes in the presynaptic membrane potential generated each
time a Ca2+ ion enters the cell.
b. the random opening of ion channels in the postsynaptic muscle cell
membrane in the absence of any electrical or chemical stimulus.
c. small depolarizations of muscle cell membrane due to the random release
of packets of transmitter substance, in the absence of any stimulation.
d. the small "reference" spike in the end plate that occurs before
facilitation takes place.
220. Quantal release of neurotransmitter refers to the fact that
a. Only one molecule is released at a time.
b. Transmitter is released in packets (units).
c. Only one axon releases transmitter at a given instant.
d. Only one packet of transmitter is released at a time.
221. Miniature end plate potentials are thought to represent
a. leakage of molecular transmitter.
b. the effect of calcium leakage into the presynaptic neuron.
c. leakage of quantal packets of transmitter substance.
d. the prelude to an action potential.
222. Quantal transmission refers to
a. the release of transmitter in discrete packets.
b. transmission from non-spiking neurons only.
c. incremental effect of pre-synaptic inhibition.
d. transmission at a neuromuscular junction only.
223. Miniature end plate potentials (mepps) are
a. the small changes in the presynaptic membrane potential each time a
Ca2+ ion enters the cell.
b. the random opening of ion channels in the postsynaptic muscle cell
membrane in the absence of any electrical or chemical stimulus.
c. small depolarizations of muscle cell membrane due to the random release
of packets of transmitter substance, in the absence of any stimulation.
d. the small "reference" spike in the end plate that occurs before
facilitation takes place.
224. The phrase "quantal transmission" refers to
a. the all or none characteristic of an action potential.
b. the transmission of discrete packets of transmitter (quanta) along
axons by axoplasmic transport.
c. the release of transmitter substance in discrete packets (quanta) at a
synapse.
d. the communication of one spiking neuron with another in units (quanta)
represented by action potentials.
225. During chemical synaptic transmission, which of the following sequences of
events occurs in a presynaptic neuron?
a. Depolarization of the terminal --> Ca2+ entry --> AP in axon -->
vesicle fusion --> transmitter release.
b. AP in axon --> depolarization of the terminal --> Ca2+ entry -->
vesicle fusion --> transmitter release.
c. Ca2+ entry --> AP in axon --> depolarization of the terminal -->
vesicle fusion --> transmitter release.
d. AP in axon --> Ca2+ entry --> depolarization of the terminal -->
vesicle fusion --> transmitter release.
226. Synaptic transmission from nonspiking neurons is referred to as graded
because
a. the amount of transmitter released is proportional to the membrane
potential.
b. transmitter is not released in discrete packets.
c. the amount of transmitter released depends on the graded size of the EPSP.
d. larger neurons release more transmitter substance than do smaller ones.
227. A nonspiking neuron
a. continually releases transmitter substance in a graded fashion.
b. does not generate action potentials because it uses only electrical
synaptic transmission.
c. is an inhibitory type of neuron that reacts by hyperpolarizing when it
is stimulated.
d. does not generate action potentials because it totally lacks Na+
channels.
228. Re-uptake is the process of entry of transmitter
a. precursor molecules into a neuron after synaptic transmission.
b. molecules into a neuron after synaptic transmission.
c. molecules through post-synaptic binding sites.
d. precursor molecules into a neuron before synaptic transmission.
229. Nearly all amino acid and amine transmitter substances appear to be
inactivated mainly by the process of
a. enzymatic breakdown.
b. chemical sequestration.
c. diffusion.
d. re-uptake.
230. Re-uptake is
a. the pumping of K+ into the cell after the passage of an AP.
b. retrograde transport that prevents too much pressure in the axonal
ending.
c. the normalization of the levels of endorphin after a patient is cured
of morphine addiction.
d. absorption of transmitter into a neuron.
231. Acetylcholine seems unusual among non-peptide transmitter substances in
that it
a. can cause an action potential directly in the synaptic membrane.
b. is inactivated entirely by extracellular enzymatic breakdown.
c. is usually found together with a neuromodulatory co-transmitter.
d. can act directly on axonal membrane to cause the opening of
voltage-sensitive sodium channels.
232. One neurotransmitter substance that is inactivated entirely by enzymatic
breakdown is
a. acetylcholine.
b. serotonin.
c. norepinephrine.
d. GABA.
233. A method for locating some specific transmitter pathways in the brain is
a. the Golgi silver stain.
b. iontophoresis.
c. intracellular staining.
d. the histofluorescence method.
234. The synthetic pathway for norepinephrine is
a. tyrosine --> DA --> DOPA --> NE.
b. tyrosine --> DOPA --> DA --> adrenaline --> NE.
c. tyrosine --> DOPA --> DA --> NE.
d. tyrosine --> adrenaline --> DA --> DOPA --> NE.
235. Part of the synthetic pathway for catecholamines in the nervous system is
a. tyrosine --> DOPA --> DA --> NE.
b. tyrosine --> DA --> DOPA --> NE.
c. tryptophan --> DOPA --> NE --> serotonin.
d. tryptophan --> DOPA --> DA --> NE.
236. Tryptophan is a precursor of
a. MAO.
b. serotonin.
c. norepinephrin.
d. COMT.
237. Tyrosine is a precursor of
a. MAO.
b. serotonin.
c. norepinephrine.
d. COMT.
238. The enzyme MAO acts in the
a. degradation of serotonin.
b. degradation of acetylcholine.
c. synthesis of dopamine.
d. synthesis of acetylcholine.
239. Octopamine is a(n)
a. amino acid.
b. catecholamine.
c. monoamine, but not a catecholamine.
d. peptide.
240. Serotonin is a(n)
a. amino acid.
b. catecholamine.
c. monoamine, but not a catecholamine.
d. peptide.
241. Proctolin is a(n)
a. amino acid.
b. catecholamine.
c. monoamine, but not a catecholamine.
d. peptide.
242. Glutamate is a(n)
a. amino acid.
b. catecholamine.
c. monoamine, but not a catecholamine.
d. peptide.
243. Dopamine is a(n)
a. amino acid.
b. catecholamine.
c. monoamine, but not a catecholamine.
d. peptide.
244. Acetylcholine is known to be a transmitter substance at
a. the vertebrate neuromuscular junction.
b. the arthropod neuromuscular junction.
c. synapses in the substantia nigra.
d. synapses involved in transmission of pain.
245. Acetylcholine is the transmitter substance at
a. the insect neuromuscular junction.
b. the vertebrate neuromuscular junction.
c. presynaptic facilitating neurons in Aplysia.
d. none of the above.
246. Which of the following substances is NOT considered a realistic candidate
for a transmitter substance?
a. Vitamin C.
b. Glycine.
c. Acetylcholine.
d. Serotonin.
247. Compared to other regions of the vertebrate brain, brainstem nuclei seem
especially rich in
a. acetylcholine.
b. substance P.
c. 5-hydroxytryptamine.
d. octopamine.
248. Most of the neurons whose cell bodies are in the Substantia nigra use
______ as a transmitter substance.
a. dopamine
b. serotonin
c. norepinephrine
d. Substance P
249. The histofluorescence technique involves the
a. production of fluorescent histones in the tissue to be studied.
b. interaction of chemicals in the tissue under study with formaldehyde to
form a fluorescent material.
c. histological study of the distribution of naturally occurring
fluorescent materials.
d. measurement of the amount of fluorescent antibodies in tissue after
appropriate chemical treatment.
250. _____ is found in high concentration in the dorsal root ganglia and the
spinal cord of vertebrates.
a. Acetylcholine
b. Serotonin
c. Endorphins
d. Substance P
251. Destruction of the Raphe nuclei or injection of certain drugs in cats
causes insomnia. Injection of 5-HTP relieves this insomnia, suggesting
that
a. 5-HTP can be used to induce sleep.
b. serotonin may be the transmitter in brain pathways that control sleep.
c. cats have neuron centers for both sleeping and wakefulness.
d. dopamine may be the transmitter in brain pathways that control sleep.
252. Neurons in the Raphe nuclei seem to use which transmitter substance?
a. Serotonin.
b. Dopamine.
c. Octopamine.
d. Epinephrine.
253. As you read this question, you find yourself getting more and more sleepy.
It is likely that certain parts of your nervous system are experiencing a
high level of
a. Acetylcholine.
b. serotonin.
c. dopamine.
d. norepinephrine.
254. The medical importance of knowing the synthetic pathway for a specific
transmitter in humans is demonstrated by the present treatment for
a. schizophrenia.
b. alcoholism.
c. Parkinson's disease.
d. extreme pain in terminally ill individuals.
255. In the treatment of Parkinson's disease, L-DOPA is used as medication
because
a. it is necessary to avoid bringing on the symptoms of schizophrenia.
b. dopamine is present in neurons of the Raphe nuclei that seem to cause
the disease.
c. the neural deficit seems to be in neurons that use DA as a transmitter.
d. L-DOPA can readily be converted to 5-HT, the substance that actually
has the therapeutic effect.
256. Dopamine is not effective as a treatment for Parkinson's disease because
a. the deficit causing the disease is a deficiency of serotonin, not
dopamine.
b. injections of dopamine cause an immunological reaction that render it
ineffective.
c. the deficit causing the disease is a deficiency of norepinephrine, not
dopamine.
d. dopamine cannot cross the blood-brain barrier.
257. Some of the peptide neurotransmitter substances seem to be especially
involved in
a. hunger.
b. pain.
c. thirst.
d. neuromuscular control.
258. A placebo may act to reduce pain by inducing the brain to
a. increase endorphin levels.
b. increase substance P levels.
c. selectively block some neuromuscular transmission.
d. increase blood glucose levels.
259. Endogenous (internal) levels of endorphin in humans are LOWERED by
a. giving birth.
b. taking a placebo against pain.
c. acupuncture.
d. addiction to opium.