Nitric oxide signaling in the brain: translation of dynamics into respiration control and neurovascular coupling

The understanding of the unorthodox actions of neuronal-derived nitric oxide ((NO)-N-center dot) in the brain has been constrained by uncertainties regarding its quantitative profile of change in time and space. As a diffusible intercellular messenger, conveying information associatedwith its concentration dynamics, both the synthesis via glutamate stimulus and inactivation pathways determine the profile of (NO)-N-center dot concentration change. In vivo studies, encompassing the real-time measurement of (NO)-N-center dot concentration dynamics have allowed us to gain quantitative insights into the mechanisms inherent to (NO)-N-center dot-mediated signaling pathways. It has been of particular interest to study the diffusion properties and half-life, the interplay between (NO)-N-center dot and O-2 and the ensuing functional consequences for regulation of O-2 consumption, the role of vasculature in shaping (NO)-N-center dot signals in vivo, and the mechanisms that are responsible for (NO)-N-center dot to achieve the coupling between glutamatergic neuronal activation and local microcirculation.