Fig. 1

Experimental protocols for examining the effects of androgens on CTA memory and extinction memory. a Experimental overview. We implanted gonadectomized mice with a hormone tube (one per individual) containing different doses of testosterone (0–2.0 mg/tube) or 5α-DHT (0–0.1 mg/tube) at 5 weeks old. After acquisition of CTA memory at 7 weeks old, mice underwent an extinction period. At 12 weeks old, they underwent a retrieval test of the extinction memory (EM). b The water-restriction training (Training) period consisted of a 20 h water-deprivation schedule and 4 h of access to distilled water (DW). On conditioning days all mice were offered a conditioned stimulus (CS) for 10 min, and then experienced malaise induced by an unconditioned stimulus (US). In contrast, mice were offered the CS for 10 min without the US during extinction days. On conditioning and extinction days, all mice were placed on a 20 h water-deprivation schedule, and Sac intake was measured for 10 min