National Certified Addiction Counselor, Level I (NCAC I) Practice Exam

Which neurotransmitter activity is increased by barbiturates?

1. Dopamine

2. GABA

3. Serotonin

4. Norepinephrine

The correct answer is: GABA

Barbiturates primarily increase the activity of GABA (gamma-aminobutyric acid), which is an inhibitory neurotransmitter in the central nervous system. When barbiturates bind to the GABA receptors, they enhance the effects of GABA, leading to increased inhibition of neuronal activity. This results in effects such as sedation, anxiolysis, anti-convulsion, and muscle relaxation. The mechanism by which barbiturates potentiate GABA action is critical in understanding their therapeutic use and potential for misuse. Increasing GABA activity helps to explain why barbiturates can be effective for treating anxiety, seizure disorders, and sleep disturbances. Additionally, this increased inhibition is responsible for the depressant effects barbiturates have on the central nervous system. The other neurotransmitters listed have different roles and do not have their activity increased by barbiturates. For example, dopamine is largely associated with the brain's reward and pleasure systems, serotonin is involved in mood regulation, and norepinephrine is related to the fight or flight response. Understanding the specific actions of barbiturates on GABA helps clarify their pharmacological profile and the effects seen in clinical use.