the GABA increase takes place and (2) the area of the brain that may mediate the anticonvulsant Investigation of the physiology, biochemistry, activity. Three compounds that increase brain pharmacology and anatomy of GAB A and GABA­ GABA by distinct mechanisms were used in these containing neural systems, continues to reveal the studies: di-n-propylacetate (DPA, sodium val­ rich complexities associated with this neuroactive proate, Depakene(R)), amino-oxyacetic acid amino acid (see recent symposia 1,2,3). Advances (AOAA) and y-vinyl GABA (GVG). in the pharmacology of GABA-mimetic agents In the next sections, the metabolism of GABA have resulted in the development of compounds and a brief historical account of the relationship that can selectively activate GABA receptors (4,5, between GABA and anticonvulsant activity are 6, 7), inhibit the synthetic and degradative enzymes outlined followed by a discussion ofthe biochemical for GABA (8, 9) or affect the neuronal and glial and pharmacological effects of the three drugs. In uptake processes for GABA (10, 11). This has particular, the literature pertaining to the suppres­ already had a significant impact on our under­ sion of seizures and the correlation between anti­ standing of the role of GABA in convulsions and a convulsant action and increases in brain G ABA will range of other CNS functions including feeding be examined. (12), cardiovascular control (13), motor activity (14) and release of pituitary hormones (15). Before 1.