Differentiation of excitatory amino acid receptors in the rat caudal trigeminal nucleus: a microiontophoretic study.
The excitatory amino acid antagonist, D-alpha-aminoadipate, was found to be a potent antagonist of responses to N-methyl-D-aspartate and L-aspartate, but less potent against L-glutamate responses of neurones in the rat caudal trigeminal nucleus. The responses to quisqualate and kainate were relatively unaffected by D-alpha-aminoadipate, but were antagonized by the two antagonists cis-2,3-piperidine dicarboxylate and gamma-D-glutamylglycine. These two antagonists had effectively similar spectra of activity. It is concluded that there is a distinct N-methyl-D-aspartate receptor in the trigeminal nucleus caudalis, and that kainate and quisqualate may act on a different, but common, receptor. Exogenously applied L-glutamate appears to act at both of these receptors, but exogenously applied L-aspartate appears to act almost exclusively on a D-alpha-aminoadipate sensitive site that may be the N-methyl-D-aspartate receptor. The kainate/quisqualate receptor is thought to be involved in the synaptic excitation of neurones in the caudal trigeminal nucleus by non-noxious mechanical stimuli.
D015074:2-Aminoadipic Acid / Q000378:metabolism*; D000600:Amino Acids, Dicarboxylic / Q000378:metabolism*; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D007608:Kainic Acid / Q000378:metabolism; D008297:Male; D010069:Oxadiazoles / Q000378:metabolism; D010880:Piperidines / Q000378:metabolism; D016318:Quisqualic Acid; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate; D009435:Synaptic Transmission; D014278:Trigeminal Nuclei / Q000378:metabolism* / Q000502:physiology
D000600:Amino Acids, Dicarboxylic; D005971:Glutamates; D010069:Oxadiazoles; D010880:Piperidines; D011956:Receptors, Cell Surface; D016194:Receptors, N-Methyl-D-Aspartate; D015074:2-Aminoadipic Acid; D001224:Aspartic Acid; D016318:Quisqualic Acid; D007608:Kainic Acid