The capillary Kir channel as sensor and amplifier of neuronal signals: Modeling insights on K ⁺ -mediated neurovascular communication

Significance Local brain activity is rapidly accompanied by a vascular response to increase blood perfusion. How neuronal activity is sensed by the vasculature is not fully understood. This process, known as neurovascular coupling, constitutes the physiological basis of functional neuroimaging scans and its disruption is associated with cognitive disorders and stroke. We have recently demonstrated the active involvement of capillary endothelial cells in neurovascular communication through the activity of Kir channels. Here, using a computational modeling approach, we investigate the biophysical determinants of capillary-mediated neurovascular coupling. Simulations show how capillary Kir channels sense neuronal activity and initiate and amplify electrical signals—through a process that resembles electrical activity in excitable cells—to produce a robust vasodilatory response.