Genes linked to mental health disorders are altered in the highly social maternal female mouse

Changes in circulating hormones and neural signaling systems contribute to the development of maternal behaviors during the transition from a virgin to postpartum state. Several genes linked to mental health disorders with social deficits are modulated during the postpartum period, and these genes may promote the increased affiliative behaviors found in maternal females. However, there are likely many unidentified genes that are also altered and contributing to maternal behaviors in the postpartum female, including genes linked to neuropsychiatric disorders. This dissertation explores gene expression alterations for candidate genes that are linked to neuropsychiatric disorders and may contribute to the enhanced sociability of the maternal female. The first study examined neurotensin (NT) and NT receptors, which are linked to maternal defense and schizophrenia, across the virgin and postpartum brain. Following the discovery of extensive alterations in NT and NT receptor expression in the medial preoptic area (MPOA), a microarray was conducted in the MPOA to further explore gene expression changes in this critically important region. Enrichment for genes linked to mental health disorders was found in the significant microarray findings. Given the role of the MPOA in social behaviors, these mental health disorder related genes may be linked to the altered social profile of the maternal female. Finally, following the examination of a collection of microarray results, fatty acid binding protein 7 (Fabp7), which is linked to schizophrenia, the presence of offspring, and neural differentiation, was analyzed across the postpartum brain. Expression was significantly down-regulated in the postpartum female compared to virgins in nearly every brain region tested, indicating that it may contribute to the construction of the highly social maternal brain. This dissertation suggests that several genes linked to mental health disorders with social deficits are altered during the transition into motherhood, with specific genes showing altered expression in several brain regions linked to maternal care. My findings contribute to a growing body of evidence suggesting that the altered sociability of the maternal female may involve changes in genes linked to mental health disorders, and thus could provide insights into neuropsychiatric disorders where there are deficits in sociability.