These images are from a precision imaging study investigating brain morphology changes associated with fluctuating steroid hormones in a human male. Colored areas depict regions that increased (purple) or decreased (orange) in volume as steroid hormones fluctuated daily. Elle Murata and colleagues found that from morning to evening steroid hormone concentrations decreased, and this diurnal rhythm was associated with diminished gray matter volume and increases in cerebrospinal fluid and ventricle size. See the article by Murata et al. for more information on rhythms in brain morphology that keep time with the daily ebb and flow of steroid hormones. Cover image: Elle Murata.