EVALUATION OF D-ALPHA-AMINOADIPATE AND D-(AND DL-)ALPHA-AMINOSUBERATE AS SELECTIVE ANTAGONISTS OF EXCITATORY AMINO-ACIDS IN THE SUBSTANTIA NIGRA AND MESENCEPHALIC RETICULAR-FORMATION OF THE RAT

The effects of microelectrophoretically applied d-α-aminoadipate and a higher homologue d-(and dl)α-aminosuberate were investigated on responses to excitatory amino acids and acetylcholine on single cells located in the substantia nigra and overlying mesencephalic reticular formation in the rat. Both compounds reversibly reduced or abolished responses to the amino acids but were without effect on acetylcholine. Responses to N-methyl-d-aspartate (NMDA) were always reduced to a greater extent than were responses to kainate while responses to l-aspartate were usually reduced more rapidly than responses to l-glutamate. In addition, d-α-aminoadipate had no effect on responses to microelectrophoretically applied substance P and neither antagonist reduced the short latency excitation of nigral cells evoked by electrical stimulation of the ipsilateral striatum. © 1979.