Control of neurovascular coupling by ATP-sensitive potassium channels.

Abstract

Regional blood flow within the brain is tightly coupled to regional neuronal activity, a process known as neurovascular coupling (NVC). In this study, we demonstrate the striking role of SUR2- and Kir6.1-dependent ATP-sensitive potassium (K_ATP) channels in control of NVC in the sensory cortex of conscious mice, in response to mechanical stimuli. We demonstrate that either globally increased (pinacidil-activated) or decreased (glibenclamide-inhibited) K_ATP activity markedly disrupts NVC; pinacidil-activation is capable of completely abolishing stimulus-evoked cortical hemodynamic responses, while glibenclamide slows and reduces the response. The response is similarly slowed and reduced in SUR2 KO animals, while animals expressing gain-of-function (GOF) mutations in Kir6.1, which underlie Cantú syndrome, exhibit baseline reduction of NVC as well as increased sensitivity to pinacidil. In revealing the dramatic effects of either increasing or decreasing SUR2/Kir6.1-dependent K_ATP activity on NVC, whether pharmacologically or genetically induced, the study has important implications both for monogenic K_ATP channel diseases and for more common brain pathologies.