Altered expression of neurotensin genes as well as neurotensin receptor genes have been exhibited in postpartum female mice. While neurotensin receptor 1 (Ntsr1) mRNA in the paraventricular nucleus of the hypothalamus (PVN) was lowered, neurotensin, but not neurotensin mRNA, was shown to be higher in the PVN. Neurotensin mRNA as well as the peptide itself were also expressed higher in the medial preoptic area (mPOA). These expression patterns were not shown in the virgin female control group, and align with other research implicating neurotensin gene expression variation in the regulation of maternal behaviors.