gamma-Aminobutyric acid system in cardiovascular and cerebrovascular function.

gamma-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the vertebrate CNS. Recent experiments have begun to delineate the roles of GABA neurons in control of both central sympathetic and parasympathetic outflows to the heart and vasculature. It is suggested that incoordination in these regions resulting from inadequate function of GABA neurons could lead to cardiac arrhythmias and large fluctuations in blood pressure that would predispose to cardiac and vascular damage. A role for GABA in cerebrovascular function is supported by the observation that specific GABA receptors and GABA-related enzymes are associated with cerebral blood vessels. It is suggested that a non-neural, indigenous GABA system in cerebral blood vessels is involved in the control of cerebrovascular tone. GABA probably plays an important role in the complex processes involved in normal regulation of cerebral circulation and its dysfunction.