Antagonism of excitatory amino acid-induced and synaptic excitation of spinal neurones by cis-2,3-piperidine dicarboxylate.

In tests on neurones in the cat spinal cord in vivo, and frog and immature rat spinal cord in vitro, cis-2,3-piperidine dicarboxylate (cis-2,3-PDA) produced the following effects: (1) selective antagonism of amino acid-induced responses, compared with responses to other putative transmitters; (2) effective antagonism of kainate and quisqualate-induced responses in addition to responses induced by N-methyl-D-aspartate (NMDA) and other excitatory amino acids; (3) partial NMDA-like agonist action; (4) antagonism of dorsal root-evoked excitation of Renshaw cells; (5) potentiation of acetylcholine- and ventral root-evoked excitation of Renshaw cells. This unique spectrum of action may be useful for transmitter receptor characterization in the vertebrate central nervous system.