Inhibitory neuromodulation of release of amino acid neurotransmitters.

Many drugs of abuse (opiates, cocaine, amphetamine, caffeine) modulate or interact with neurotransmitter systems in the brain (e.g., opiate, dopaminergic, adrenergic, purinergic), generally in an inhibitory fashion. However the cellular mechanisms underlying these interactions are varied and often not well-characterized. A summary of the literature on the neuromodulation of two amino acid neurotransmitters (gamma-aminobutyric acid, glutamate) by these drugs and their analogs may contribute to the understanding of the mechanisms underlying inhibitory neuromodulation. In addition, the types of experiments needed to alleviate some of the problems in this area are outlined.