What does GABA primarily function as in the central nervous system?

GABA, or gamma-aminobutyric acid, is primarily known as an inhibitory neurotransmitter in the central nervous system. Its main function is to reduce neuronal excitability throughout the brain and nervous system. By binding to its receptors, GABA facilitates the opening of ion channels that allow negatively charged ions into the neuron, making it less likely to fire an action potential. This inhibitory action plays a crucial role in regulating various physiological and psychological processes, including muscle tone, anxiety, and sleep.

In contrast, excitatory neurotransmitters promote the generation of electrical signals in neurons, hormones are chemical messengers that coordinate activities in different parts of the body, and vasopressors refer to substances that constrict blood vessels and increase blood pressure. Understanding GABA's role as an inhibitory neurotransmitter is essential for grasping how balance between excitation and inhibition is maintained in the nervous system, crucial for overall brain function and mental health.