Two important neurotransmitters involved in the regulation of brain neuronal activity are γ-aminobutyric acid (GABA), one of the most widely distributed inhibitory neurotransmitters, and L-glutamic acid, an excitatory neurotransmitter. The concentration of GABA is regulated by two pyridoxal 5'-phosphate dependent enzymes: L-glutamic acid decarboxylase (GAD; EC 4.1.1.15), which catalyzes the conversion of L-glutamate to GABA, and GABA aminotransferase, which degrades GABA to succinic semialdehyde. When the concentration of GABA diminishes below a threshold level in the brain, convulsions result; raising the brain GABA levels appears to terminate the seizure. A reduction in the concentrations of GABA and of GAD has been implicated in the symptoms associated with epilepsy as well as several other neurological diseases such as Huntington's chorea, Parkinson's disease, Alzheimer's disease, and tardive dyskinesia. Administration of GABA peripherally is not effective because GABA cannot cross the blood-brain barrier (presumably due to its lipophobicity). Several approaches have been taken to increase the brain concentrations of GABA, including making prodrugs of GABA and inactivating GABA aminotransferase. Another untapped approach is to design activators of GAD. Two anticonvulsant agents, milacemide and sodium valproate, have been reported to activate GAD to a small extent in vivo, but these compounds were not investigated in vitro with purified GAD to determine their direct effect on the enzyme. During investigations of the effects of 3-alkyl GABA analogues as alternative substrates for GABA aminotransferase, the authors tested these compounds with GAD and found that they caused activation. Here they communicate their initial studies with these analogues, which constitute the first class of activators of GAD in vitro, and show that they also have anticonvulsant activity.