Ovariectomized Rat Sexual Receptivity Study

Wistar female rats without sexual experience were used for this study. They were bilaterally ovariectomized (OVX) under anesthesia with a mixture of ketamine (95 mg/kg) and xylazine (12 mg/kg). Two weeks later and to induce sexual receptivity, OVX females received a subcutaneous (sc) injection of E2 benzoate (25 μg/rat; Sigma St. Louis, Missouri, USA) and progesterone (1 mg/rat; Sigma), 48 and 4 hours respectively, before the behavioral test. These doses were used to induced high levels of sexual receptivity and we have used them repeatedly before [33 (link), 34 ]. For Sexual behavior tests, sexually experienced males were used as stimulus. Experiments were approved by the Instituto de Neurobiología Animal Care Committee which follows NIH guidelines for the use and care of animals.