Sexual behavior and scent marking in male gerbils: comparison of changes after castration and testosterone replacement

This study compared changes in sexual behavior of male gerbils with changes in scent-marking frequency following castration and exposure to various doses of testosterone. Castration eliminated sexual activity in male gerbils. Injections of testosterone propionate (75 μg twice weekly) prevented this decrease. Larger (600 μg) injections of testosterone propionate or implantation of Silastic capsules of testosterone reinstated mating behavior. Sexual behavior showed a different pattern of changes than scent marking. Sexual behavior was maintained more effectively than scent marking by hormone injections, but scent marking was reinstated more readily than sexual behavior by the tonic hormone levels produced by Silastic implants.