In Vivo: Gepirone (0-3 mg/kg for intraperitoneal injection) interacts with progesterone at 5-HT1A receptors to reduce lordosis behavior in female rats treated with estradiol benzoate and progesterone. Gepirone (10, 15 mg/kg for subcutaneous injection, 2, 7, or 14 days) activates the normosensitive postsynaptic 5-HT1A receptor in Male Sprague-Dawley rats.