Simultaneous mesoscopic imaging of neural activity and hemodynamics reveals anesthetic modulation of neurovascular responses.

Anesthesia substantially alters neural activity and vascular tone, yet its state-dependent modulation of cortical neurovascular coupling (NVC) remains incompletely characterized. Here, using an established multimodal optical imaging platform that synchronizes wide-field fluorescence microscopy, photoacoustic microscopy, and laser speckle contrast imaging, we investigated anesthesia-dependent modulation of cortical neurovascular dynamics in mice. We characterized neurovascular responses under isoflurane (ISO), dexmedetomidine (Dex), and low-dose ISO-Dex, and used focal 4-aminopyridine (4-AP) injections to examine seizure-associated responses across awake, ISO, and ISO-Dex conditions. Isoflurane suppressed neural activity, elevated vascular baselines, and induced a neurovascular washout that markedly attenuated seizure-related hemodynamic responses. Dexmedetomidine was associated with relatively preserved neural activity but induced vasoconstriction. In contrast, ISO-Dex reduced ISO-associated vasodilation and retained measurable seizure-associated neurovascular dynamics within this 4-AP seizure paradigm. These results demonstrate that anesthetic state is an active determinant of neurovascular signal fidelity and should be carefully considered when interpreting functional neurovascular imaging data.