National Certified Addiction Counselor, Level 2 (NCAC II) Practice Exam 2026 – All-in-One Guide to Exam Success!

Gamma-Amino-Butyric Acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. Its main function is to reduce neuronal excitability throughout the nervous system by binding to its receptors, leading to hyperpolarization of neurons, which inhibits their firing. This action is crucial for maintaining the balance between excitatory and inhibitory signals in the brain, thereby regulating various physiological and psychological functions.

Central nervous system stimulants primarily enhance the activity of excitatory neurotransmitters but can also impact GABAergic systems. While stimulants increase levels of neurotransmitters like dopamine and norepinephrine, GABA's inhibitory role can be affected by those same stimulants, leading to altered states of arousal, mood, and overall brain activity. Increased excitatory neurotransmission can sometimes lead to a temporary reduction in GABAergic activity as the brain tries to adjust to the heightened stimulation.

The other neurotransmitters listed have different roles and mechanisms. Serotonin plays a role in mood regulation and has complex effects, often exerting both inhibitory and excitatory actions depending on the receptor it binds to. Dopamine is mainly associated with reward and pleasure pathways, often regarded as an excitatory neurotransmitter. Acetylcholine is involved in both