Which neurotransmitter is the primary inhibitory transmitter in the CNS and a major target for anti-anxiety drugs?

• A. Dopamine
• B. GABA
• C. Glutamate
• D. Endorphins

Answer: (B)

GABA is the brain’s main brake on neural activity. It reduces excitability by binding to GABA-A receptors, which opens chloride channels and hyperpolarizes neurons, making them less likely to fire. This widespread inhibition helps calm neural circuits involved in anxiety and arousal. Anti-anxiety drugs, especially benzodiazepines, work by enhancing GABA’s effect at the GABA-A receptor, increasing the likelihood that the chloride channel opens and boosting inhibition in anxiety-related pathways.

Dopamine is more about reward and motivation; glutamate is the primary excitatory transmitter; endorphins are endogenous opioids that modulate pain and mood, not the main inhibitory transmitter.