Paradoxical effect of the volatile anesthetic isoflurane on calcium activity of cortical vascular endothelial cells in vivo

SignificanceTranscranial optical imaging in vivo enables monitoring of the effects of volatile anesthetics on the calcium activity of specific cell types in the cerebral cortex of awake mice.AimWe aim to determine the effects of isoflurane anesthesia on the calcium activity of cortical vascular endothelial cells in vivo.ApproachTranscranial two-photon microscopy was used to measure the effects of isoflurane anesthesia on the calcium activity of vascular endothelial cells in vessel segments of different diameters and locations in the upper layers of the somatosensory cortex of Cdh5BAC-GCaMP mice.ResultsIsoflurane anesthesia induced persistent dilation and constriction effects on most vessel segments examined. Functionally, isoflurane reduced the number of calcium events, suppressed mean fluorescence levels, and increased the variability of activity during the different steps of the anesthesia protocol. Paradoxically, isoflurane induced an increase in calcium events from endothelial cells prior to a decrease in activity.ConclusionsWe demonstrate that isoflurane anesthesia has persistent effects on vessel diameter and functional effects that consist of both increases and reductions of calcium activity in endothelial cells from a wide range of vessel segments in the superficial layers of the mouse somatosensory cortex.