Nitric oxide actions in neurochemistry.

The discovery of the role of nitric oxide (NO) as a messenger molecule in the central nervous system has radically altered our conception of neuronal communication. Information has been generated at a rapid pace in the last few years regarding the biochemistry, enzymatic activity and molecular characteristics of NO synthase (NOS) and NO synthesis, and the biological consequences of NO production. The full scope of the biological consequences of NO production is unknown but putative cellular targets of NO are rapidly being discovered as well as potential physiological and pathophysiological roles in the nervous system. Roles for NO have been identified in neurotransmitter release, morphogenesis, synaptic plasticity, regulation of gene expression, as well as mediation of inhibitory processes associated with sexual and aggressive behaviour. Inappropriate formation of NO is emerging as an important factor in the neurotoxicity associated with a variety of central nervous system disorders. The current information on the various roles of NO as a neuronal messenger molecule as well as a neurotoxin are reviewed in this article.