Pharmacology III – CNS Module Practice Exam

Benzodiazepines primarily function through the enhancement of GABA (gamma-aminobutyric acid) activity in the central nervous system. GABA is the main inhibitory neurotransmitter in the brain, and its action helps to decrease neuronal excitability.

Benzodiazepines bind to specific sites on the GABA-A receptor, which is a type of ionotropic receptor. This binding increases the frequency of chloride ion channel opening, leading to an influx of chloride ions into the neuron. The increase in chloride conductance results in hyperpolarization of the neuron, making it less likely to fire and thus contributing to the anxiolytic, hypnotic, muscle relaxant, and anticonvulsant effects characteristic of benzodiazepines.

This mechanism is distinct from other processes in the CNS. For instance, inhibiting serotonin reuptake is related to the action of selective serotonin reuptake inhibitors (SSRIs) and does not pertain to benzodiazepines. Similarly, the blockade of dopamine receptors is typical of antipsychotic medications, which work to mitigate symptoms of psychosis rather than enhance inhibitory signaling. Lastly, stimulation of adrenergic receptors is associated with increase in alertness or arousal, which is contrary to the