What is the inhibitory neurotransmitter that is widely distributed in the brain?

GABA, or gamma-aminobutyric acid, is recognized as the primary inhibitory neurotransmitter in the brain. It functions by binding to its receptors and increasing chloride ion permeability in neuronal membranes, which leads to hyperpolarization of the neurons. This hyperpolarization decreases the likelihood of action potentials, effectively inhibiting neuronal activity. GABA's wide distribution throughout the brain plays a crucial role in regulating excitability, maintaining the balance between excitation and inhibition, and modulating various physiological processes, including muscle tone, anxiety, and the sleep-wake cycle. Understanding the role of GABA is foundational in veterinary pharmacology, as many drugs target GABAergic systems to manage conditions such as seizures and anxiety disorders in animals.