Steroid regulation of territorial scent marking in the Mongolian gerbil (Meriones unguiculatus)

Mongolian gerbils (Meriones unguiculatus) display a territorial scent marking response associated with a ventral sebaceous gland. In males, both the gland and behavior are androgen dependent and hormone control of marking is delimited to the preoptic area. The present study examines the effects of eleven steroids, injected subcutaneously or implanted into the preoptic area, on territorial marking in adult male castrates. Steroid effects on ventral gland function are also described. The neural target cells that mediate marking respond to a narrower range of steroids than do peripheral target cells in the ventral gland. Testosterone appears to be the only endogenous steroid capable of eliciting marking in males. Other steroids which share molecular commonalities with testosterone (a 17β-hydroxyl group and a double bond involving carbon 4) also induce marking behavior. Central receptors may recognize the relevant endogenous steroid, testosterone, by these features.