Nitric oxide modulates spontaneous cord dorsum potentials in the cat spinal cord

A previous study has shown that lumbar spontaneous cord dorsum potentials ( CDPs) are produced by background activity of a neuronal ensemble located in the dorsal horn. Here, the effects produced by intravenous application of the nitric oxide synthase inhibitor L-N-G-nitro arginine (L-NOARG, 100 mug/ kg) and of the nitric oxide donor 3-morpholino-sydnonimine hydrochloride (S IN-1, 500 mug/kg) on spontaneous CDPs were examined. Experiments were perfo rmed on pentobarbitally anesthetized, paralyzed and spinalized cats. The am plitude of spontaneous CDPs increased after L-NOARG, however, decreased aft er SIN-1. These observations suggest that electrical activity of dorsal hor n neurones generating spontaneous CDPs is dependent on nitric oxide product ion. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.