Fig. 2.

Androgens change circadian responses to constant dim light. A, Actograms show wheel running activity in constant darkness (DD, left) or dim red light (right) in intact, GDX, and T-replaced animals. Open circle, Time of surgery. B–E, Quantification of surgery and group effects on parameters of wheel running (mean ± SE), including period (B), onset precision (C), amount of activity in counts/min (D), and activity duration, alpha (E). Different letters and * indicate significant between-group differences post-surgery (P < 0.05).