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The NO‐cGMP Pathway in Neonatal Rat Dorsal Horn
Author(s) -
Morris R.,
Southam E.,
Gittins S. R.,
Vente J.,
Garthwaite J.
Publication year - 1994
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.1994.tb00998.x
Subject(s) - nmda receptor , chemistry , ampa receptor , glutamate receptor , cyclic guanosine monophosphate , nitric oxide , nitric oxide synthase , neuropil , medicine , spinal cord , endocrinology , biochemistry , receptor , biology , central nervous system , neuroscience
Incubation of slices of neonatal rat spinal cord with nitric oxide donor compounds produced marked elevations in cyclic guanosine 3′,5’monophosphate (cGMP) levels. The excitatory amino acid receptor agonists N ‐methyl‐ d ‐aspartate (NMDA) and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate (AMPA) produced smaller increases, which were blocked by the nitric oxide synthase (NOS) inhibitor M l ‐ N G ‐nitroarginine (NOArg), indicating that these cGMP responses were mediated by nitric oxide. Immunocytochemistry revealed that, in response to NMDA, cGMP accumulated in a population of small cells and neuropil in laminae II and III of the dorsal horn. This area was also shown, by reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry, to contain NOS. These observations suggest that, in the rat spinal cord, NMDA receptor activation is linked to the formation of NO and, hence, of cGMP. This pathway is located selectively in the superficial dorsal horn, consistent with a role in the processing of nociceptive signals.