Nitric oxide, induced by kainate application, regulates norepinephrine release in the laterodorsal tegmental nucleus of rats

Abstract

Nitric oxide (NO) released from the cholinergic neurons may play important roles in sleep-wake regulation. We reported a possible role of NO, which was mediated through n-methyl-d-aspartic acid (NMDA) receptors in the cholinergic neurons in pons, as a retrograde regulator of norepinephrine (NE) release from the locus coeruleus neurons. In this study, we further investigate the effect of kainate application. There were significant increases in concentration of NO (P < 0.05) for 20 min, in NE (P < 0.05) for 15 min, and in cyclic guanine monophosphate (cGMP; P < 0.05) for 60 min after the initiation of kainate application (5 mmol/L). The difference in the distributions of NMDA and kainate receptors in the dorsolateral pontine tegmental nucleus (LDT) may explain the different firing patterns of LDT neurons.