Question

Which is/are the most common inhibitory neurotransmitter(s) of the CNS?

A) GABA
B) glycine
C) glutamate
D) A and B
E) all of the above

Answer 1

The most common inhibitory neurotransmitters of the CNS are GABA and glycine; glutamate is an excitatory neurotransmitter. Hence, the correct answer is D) A and B.

Step-by-step explanation:

The most common inhibitory neurotransmitters of the central nervous system (CNS) are gamma-aminobutyric acid (GABA) and glycine. GABA is synthesized from glutamate and is prevalent throughout the brain, where it serves to reduce neuronal excitability by causing hyperpolarization of the postsynaptic cell.

Glycine acts similarly but is primarily found in the spinal cord and brainstem. Glutamate, by contrast, is the main excitatory neurotransmitter in the CNS. Thus, the correct answer to the question is D) A and B, meaning GABA and glycine are the most common inhibitory neurotransmitters.