NO is a retrograde neurotransmitter that plays a role in the regulation of cerebral blood flow and has important roles in intracellular signaling in neurons from the regulation of the neuronal metabolic status to the dendritic spine growth [4]. NO is synthesized by three isoforms of NO synthase (NOS): neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). nNOS and eNOS are constitutively expressed in the brain and regulate basal NO levels, while iNOS is induced in response to pathological and physiological events [3].
Neuroprotection and Aging
NO also plays a role in neuroprotection and aging. NO has been shown to have both neuroprotective and neurotoxic effects, depending on the concentration and duration of exposure [2]. NO has been implicated in the pathogenesis of several neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease [3]. In addition, NO has been shown to play a role in the aging process, as NO levels decrease with age [1].
In summary, NO plays a crucial role in cognitive functions such as memory and learning, neurotransmission and signaling, and neuroprotection and aging. NO is a versatile molecule that regulates many physiological processes in the brain, and its dysregulation has been implicated in several neurological disorders.
