The ability of oxytocin to induce short latency maternal behavior is dependent on peripheral anosmia.
Nulliparous female Sprague-Dawley rats, cannulated in the left lateral ventricle, were ovariectomized and estrogen primed, then either rendered anosmic via intranasal irrigation with zinc sulfate or left with intact olfaction. Forty-eight hr later, after a 2-hr habituation to the test cage, these animals were injected with either intracerebroventricular oxytocin (400 ng in 2 microliter saline) or saline (2 microliter). Only the group receiving both zinc sulfate and oxytocin became maternal. Additionally, approximately one third of the olfaction-intact rats and none of the anosmic rats cannibalized the rat pups. These results are discussed in regard to discrepancies in the literature regarding oxytocin's role in inducing maternal behavior, as well as the functional connection of the olfactory and oxytocin systems.