Benzodiazepines exert their anxiolytic effect by enhancing GABA-A receptor function through which mechanism?
- A Increasing the duration of chloride channel opening
- B Increasing the frequency of chloride channel opening ✓
- C Directly opening the chloride channel independent of GABA
- D Blocking GABA reuptake into presynaptic terminals
Correct answer: B. Increasing the frequency of chloride channel opening
Explanation
Benzodiazepines increase the frequency of chloride channel opening when GABA binds to GABA-A receptors, producing anxiolysis and sedation. Barbiturates, by contrast, increase the duration of channel opening. This distinction explains the wider safety margin of benzodiazepines compared to barbiturates.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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