Fig. 1.

Schematic showing the experimental schedule. Light-dark (LD) cycle is represented by alternating light and dark bars. Animals received daily injections of oil followed by estradiol benzoate (EB) (black arrows) or oil only (gray arrows) before baseline and sleep deprivation (SD). In the first experiment, SD began at lights on (A), whereas in the second experiment SD began in the midlight phase (B). Recovery thus consisted of 6 h of light followed by 12 h of darkness (Recovery-Light; A) or vice versa (Recovery-Dark; B).