What is the primary mechanism of action of benzodiazepines?

Benzodiazepines primarily act by binding to the gamma subunit of the GABA(A) receptor complex. This binding enhances the effect of GABA, the principal inhibitory neurotransmitter in the brain. When benzodiazepines attach to the gamma subunit, they facilitate the opening of the associated chloride channels more frequently upon GABA binding. This leads to an increased influx of chloride ions into the neuron, resulting in hyperpolarization and decreased neuronal excitability.

This mechanism is central to the anxiolytic, sedative, muscle relaxant, anticonvulsant, and amnesic effects of benzodiazepines, making them effective in treating various conditions such as anxiety disorders, insomnia, and seizure disorders.