The nitric oxide pathway: potential implications for treatment of neuropsychiatric disorders.

The freely diffusible gaseous compound nitric oxide (NO) has recently been discovered to be an important cellular messenger in many organ systems throughout the body. The importance of NO as an intermediary in cell communication in the brain is highlighted by the fact that the excitatory amino acid glutamate, the most abundant central neurotransmitter, is an initiator of the reaction that forms NO. In this article, background information about the discovery of NO, its biochemistry, and a brief summary of some of its peripheral and central actions are given to provide a complete picture of this remarkable novel second messenger. We also discuss how an improved understanding of NO pathway may lead to the identification of novel medications for the treatment of a number of neuropsychiatric conditions, including memory deficits, pain, drug addiction, seizures, bipolar disorder, psychosis, eating disorders, and the treatment of the sequelae of various brain injuries.