Question 1

Which of the following best describes the process by which neurotransmitters are released from the presynaptic terminal?

Accepted Answer

Neurotransmitters are released via Ca$$^{2+}-$$mediated exocytosis, which involves the influx of Ca$$^{2+}$$ through voltage-gated channels triggering vesicle fusion with the membrane.

Question 2

A patient is given a drug that inhibits acetylcholinesterase (AChE). What is the most likely effect on synaptic transmission at cholinergic synapses?

Accepted Answer

The duration of acetylcholine signaling in the synaptic cleft will increase, leading to prolonged postsynaptic activation.

Question 3

Which of the following scenarios best illustrates spatial summation in a postsynaptic neuron?

Accepted Answer

Multiple presynaptic neurons fire simultaneously, and their combined excitatory postsynaptic potentials (EPSPs) depolarize the postsynaptic neuron to threshold.

Question 4

Which of the following is a direct result of increased frequency of action potentials arriving at the presynaptic terminal?

Accepted Answer

Greater influx of Ca$$^{2+}$$ and increased neurotransmitter release.

Question 5

Which neurotransmitter is synthesized and packaged at the presynaptic terminal, rather than the soma?

Accepted Answer

Acetylcholine

Question 6

A neuron receives both excitatory and inhibitory inputs at the same time. What determines whether the neuron will fire an action potential?

Accepted Answer

The net summation of all EPSPs and IPSPs at the axon hillock must reach threshold ($$V_{m} \geq V_{threshold}) $$for an action potential to occur.

Question 7

Which of the following best describes the role of SNARE proteins in neurotransmitter release?

Accepted Answer

SNARE proteins mediate vesicle fusion with the presynaptic membrane, allowing neurotransmitter exocytosis.

Question 8

Which of the following is an example of postsynaptic modulation?

Accepted Answer

Changing the number or affinity of neurotransmitter receptors on the postsynaptic cell.

Question 9

Which of the following neurotransmitters acts primarily through ionotropic glutamate receptors (such as AMPA and NMDA)?

Accepted Answer

Glutamate

Question 10

A neuron receives input from several presynaptic neurons at different locations, but none of the individual EPSPs reach threshold. What mechanism allows the postsynaptic neuron to fire?

Accepted Answer

Spatial summation, where multiple simultaneous EPSPs combine to reach threshold.

Question 11

Which of the following is true regarding the termination of neurotransmitter activity in the synaptic cleft?

Accepted Answer

Termination occurs by breakdown, reuptake, or diffusion of the neurotransmitter away from the synapse.

Question 12

Which of the following best describes the concept of convergence in neural circuits?

Accepted Answer

Multiple presynaptic neurons synapse onto a single postsynaptic neuron.

Question 13

Which of the following would most likely result from axo-axonic synaptic inhibition?

Accepted Answer

Decreased neurotransmitter release from the presynaptic neuron.

Question 14

Which neurotransmitter is associated with both ionotropic and metabotropic receptors in the CNS, and is the primary inhibitory neurotransmitter?

Accepted Answer

GABA ($$\gamma-$$aminobutyric acid)

Question 15

A postsynaptic neuron is exposed to a neurocrine that acts as a neuromodulator. Which of the following is most likely to occur?

Accepted Answer

The neurocrine will activate G protein-coupled receptors, leading to longer-lasting effects on the postsynaptic cell.

Question 16

Which of the following is a key difference between peptide neurotransmitters and small-molecule neurotransmitters like acetylcholine?

Accepted Answer

Peptide neurotransmitters are synthesized and packaged in the soma, then transported to the terminal, while small-molecule neurotransmitters are synthesized and packaged at the terminal.

Question 17

Which of the following would most likely increase the postsynaptic cell's responsiveness to a neurotransmitter?

Accepted Answer

Upregulation of receptor number or affinity on the postsynaptic membrane.

Question 18

Which of the following best describes temporal summation?

Accepted Answer

Multiple graded potentials from the same presynaptic neuron arrive at the postsynaptic cell in rapid succession and are summed.

Question 19

Which of the following is true regarding the effect of an inhibitory postsynaptic potential (IPSP) on a neuron?

Accepted Answer

An IPSP typically results from the influx of Cl$$^{-} or $$efflux of K$$^{+}$$, causing hyperpolarization and making it less likely for the neuron to reach threshold.

PreM #6 Neural Communication and Synaptic Transmission: Study Notes for Anatomy & Physiology

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드