Final answer:
GABA functions as the main inhibitory neurotransmitter in the brain, regulating neuronal activity. Glycine acts as an inhibitory neurotransmitter in the spinal cord, involved in pain perception and muscle regulation.
Step-by-step explanation:
GABA, which stands for gamma-aminobutyric acid, functions as the main inhibitory neurotransmitter in the brain. It helps regulate the overall activity of neuronal networks by inhibiting excessive excitatory activity. GABA exerts its effects through three types of receptors: GABAA, GABAB, and GABAC receptors.
Glycine, on the other hand, functions as an inhibitory neurotransmitter in the spinal cord and brainstem. It is involved in pain perception and modulation, as well as in the regulation of muscle tone and movement. Glycine is primarily released from neurons by exocytosis and acts on glycine receptors to cause hyperpolarization of the postsynaptic cell.