INTRODUCTION TO THE ROLE OF EXCITATORY AMINO-ACIDS IN THE ACTIONS OF ABUSED DRUGS - A SYMPOSIUM PRESENTED AT THE 1993 ANNUAL-MEETING OF THECOLLEGE-ON-PROBLEMS-OF-DRUG-DEPENDENCE

Recent evidence has demonstrated that N-methyl-D-aspartic acid (NMDA) and non-NMDA, excitatory amino acid (EAA) receptor antagonists block t he motor stimulating, neurotoxic, and rewarding actions of cocaine and the amphetamines. The participants in this symposium discussed eviden ce that (i) the initiation of stimulant-induced behavioral sensitizati on involves NMDA receptor stimulation in the ventral tegmental area (V TA), (ii) competitive and non-competitive NMDA antagonists block the d opaminergic neurotoxic actions of methamphetamine, and (iii) NMDA rece ptor antagonists block cocaine and methamphetamine-induced increases i n striatal neurotensin and dynorphin expression. Furthermore, a theore tical framework was proposed in which to interpret dopamine-glutamate interactions based on tonic and phasic dopamine release in the striatu m under acute, chronic and withdrawal states of stimulant exposure.