Pharmacological differentiation between responses of rat medullary dorsal horn neurons to noxious mechanical and noxious thermal cutaneous stimuli.

Response of lamina V medullary dorsal horn neurons to noxious thermal and noxious mechanical facial stimuli were challenged with iontophoretically applied cis-2,3-piperidine dicarboxylic acid, a broad spectrum excitatory amino acid antagonist. This antagonist reduced neuronal responses to noxious mechanical stimuli but not responses to noxious thermal stimuli. These results suggest that different neural mechanisms underlie the responses of lamina V neurons to different noxious stimuli, and that responses to noxious mechanical stimuli appear to involve excitatory amino acid receptors.