Representative anatomic and actigraphic data. Immunohistochemical staining of human suprachiasmatic nucleus for vasoactive intestinal peptide (VIP) (A, C) and arginine vasopressin (AVP) (B, D). Low power (a, b, scale bar = 1 mm) and high power views (c, d, scale bar = 100 μm) from a single subject in consecutive sections. (E) Visualization of actigraphy data from an illustrative participant. (Inset: detail view of 48 hours of this recording). OC = Optic Chiasm; PVN = Paraventricular Nucleus; SCN = Suprachiasmatic Nucleus; SON = Supraoptic Nucleus; 3V = 3rd ventricle.