Question 1

Which of the following best describes the primary difference between electrical and chemical synapses?

Accepted Answer

Electrical synapses transmit signals via direct ionic current through gap junctions, while chemical synapses rely on neurotransmitter release across a synaptic cleft.

Question 2

During the process of neurotransmitter release at a chemical synapse, which event occurs immediately after voltage-gated Ca$^{2+}$ channels open?

Accepted Answer

Synaptic vesicles undergo exocytosis.

Question 3

A patient is given a drug that inhibits acetylcholinesterase. What is the most likely effect at a cholinergic synapse?

Accepted Answer

Increased duration of acetylcholine action on the postsynaptic cell.

Question 4

Which of the following best explains why NMDA receptors require both glutamate binding and depolarization to open?

Accepted Answer

They are blocked by Mg$^{2+}$ at resting membrane potential, which is relieved only by depolarization.

Question 5

A neuron receives multiple excitatory postsynaptic potentials (EPSPs) from different synapses on its dendrites at the same time. This is an example of:

Accepted Answer

Spatial summation

Question 6

Which of the following is TRUE regarding GABA$_A$ receptors?

Accepted Answer

They mediate inhibitory transmission by allowing Cl$^-$ influx.

Question 7

Which of the following best describes the mechanism of action of SSRIs (Selective Serotonin Reuptake Inhibitors)?

Accepted Answer

They inhibit serotonin reuptake, prolonging serotonin signaling.

Question 8

Which of the following equations best represents the reversal potential ($E_{rev}$) for an ion channel permeable to both Na$^+$ and K$^+$?

Accepted Answer

$E_{rev} = \frac{g_{Na}E_{Na} + g_{K}E_{K}}{g_{Na} + g_{K}}$

Question 9

A synapse is described as having a latency of 1–2 ms between presynaptic action potential and postsynaptic response. Which type of synapse is this most likely to be?

Accepted Answer

Chemical synapse

Question 10

Which of the following is a correct sequence of events in the synaptic vesicle lifecycle at a chemical synapse?

Accepted Answer

Neurotransmitter synthesis → Vesicle loading → Docking/priming → Exocytosis

Question 11

A neuron is exposed to a drug that increases the conductance of Cl$^-$ channels at rest. What is the most likely effect on excitatory postsynaptic potentials (EPSPs)?

Accepted Answer

EPSPs will be reduced due to shunting inhibition.

Question 12

Which of the following neurotransmitters is the major excitatory neurotransmitter in the central nervous system?

Accepted Answer

Glutamate

Question 13

Which of the following best explains why the postsynaptic response at an electrical synapse is almost immediate?

Accepted Answer

Direct ionic current passes through gap junctions, allowing for minimal delay.

Question 14

A researcher blocks all ligand-gated ion channels in a neuron. Which type of neurotransmitter receptor is directly affected?

Accepted Answer

Ionotropic receptors

Question 15

Which of the following is a key feature of metabotropic neurotransmitter receptors?

Accepted Answer

They activate second messengers, leading to amplification and widespread effects.

Question 16

Which of the following best describes the role of neuropeptides in synaptic transmission?

Accepted Answer

They act as neuromodulators with diverse modulatory roles.

Question 17

A neuron receives multiple action potentials at the same synapse in rapid succession, resulting in a larger postsynaptic potential. This phenomenon is known as:

Accepted Answer

Temporal summation

Question 18

Which of the following is required for NMDA receptor activation and subsequent synaptic plasticity?

Accepted Answer

Binding of glutamate and depolarization to relieve Mg$^{2+}$ block

Question 19

Which of the following best describes the effect of cocaine on synaptic transmission?

Accepted Answer

It blocks dopamine reuptake, enhancing dopamine action.

Synaptic Transmission: Types, Mechanisms, and Integration

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