Influence of nitric oxide on the activity of cuneate neurons in the rat.
Some neurons of main and external cuneate nuclei are immunoreactive for nitric oxide (NO) synthase, suggesting a role for endogenous NO in the early stages of somatosensory processing. We tested this hypothesis by investigating the possibility that NO modulates cuneate discharge. We observed that both spontaneous and N-methyl-D-aspartate-evoked activities of cuneate neurons were decreased by NO precursor L-arginine. The inhibition of NO synthase, by application of N-nitro-L-arginine methyl ester, instead, abolished the depressant effect induced by L-arginine. Our data suggest a NO modulation of cuneate neurons and provide support for a physiologic role not only in increasing the signal-to-noise ratio in the excited cells but also in a form of surround inhibition.
Garifoli
Angelo
A
Department of Physiological Sciences, University of Catania, Catania, Italy.
Maci
Tiziana
T
Perciavalle
Valentina
V
Perciavalle
Vincenzo
V
D000818:Animals; D001120:Arginine / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D008526:Medulla Oblongata / Q000378:metabolism*; D008839:Microelectrodes; D008845:Microinjections; D016202:N-Methylaspartate / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D016202:N-Methylaspartate; D001120:Arginine; D019001:Nitric Oxide Synthase