Two-Photon Microscopy to Measure Blood Flow and Concurrent Brain Cell Activity

The cerebral vascular system services the constant demand for energy during neuronal activity in the brain. Attempts to delineate the logic of neurovascular coupling have been greatly aided by the advent of two-photon laser scanning microscopy to concurrently image blood flow and the activity of individual neurons and astrocytes involved in the control of the flow. Here we review the procedures to generate optical access to the cortex for both rats and mice, determine the receptive fields of the exposed cortical areas, and use two-photon microscopy to accurately measure blood flow in individual cortical vessels concurrent with local cellular activity. We illustrate the techniques with acute recordings from rats and chronic recordings from mice.