Intact-skull cranial windows for widefield optical imaging in juvenile mice: complications and consequences

Functional neuroimaging with widefield optical imaging (WOI) is potentially useful for studying developmental disorders in juvenile mice. However, WOI requires an intact-skull cranial window, and the effects of such windows on young mice are unknown. We performed intact-skull cranial window placement on mice as young as P7 to study the effects of chronic placement. Cranial windows placed at young ages (P7 and P10) were not longitudinally stable, resulting in significant attrition. Windows placed at ages P14 or less resulted in significant impairment to skull growth, which in turn caused artifacts in resting-state functional connectivity analysis. Longitudinal cranial windows should likely be avoided under P30.