Social and Behavioral Sciences Commons^™

The Hormones Of Pregnancy Alter Somal Size In The Medial Preoptic Area Of The Rat Brain, Lori A. Keyser

Master's Theses

Formerly non-responsive females will display maternal behavior (MB) following pregnancy and parturition. The behavioral alterations are believed to occur in response to hormonal changes that accompany pregnancy. The medical pre optic area (MPOA) regulates hormone-induced MB. The current study examined neuronal changes which might account for the modified behavior. Twenty adult female Sprague-Dawley rats were assigned a hormone condition: ovariectomized (OVX), ovariectomized/hormone-treated (P+E₂), intact diestrus (DI), or pregnant (PREG). Animals were killed, and their brains fixed in Golgi-Cox solution. Somata of the MPOA and related cortex were measured in each group using a Bioquant imaging system. Pregnant females …