The Deletion of GPR40/FFAR1 Signaling Damages Maternal Care and Emotional Function in Female Mice.

ABSTRACT

The free fatty acid receptor 1 (GPR40/FFAR1) is activated by polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acids (DHA). This receptor has been the focus of many studies regarding physiological functions of the central nervous system. PUFAs are essential for neuronal development and maintenance of neuronal function; thus, the decrease of PUFAs in the brain is closely related to the induction of psychiatric diseases associated with emotional disorder, such as anxiety, depression, and schizophrenia. However, details of the mechanisms remain unclear. In this study, we investigated changes of maternal and/or emotional behavior caused by a deficiency of GPR40/FFAR1 signaling. GPR40/FFAR1 deficient (FFAR1-/-) female mice exhibited impaired maternal care such as retrieving behaviors and an increased rate of neglect and infanticide when compared to wild type (WT) female mice. Furthermore, FFAR1-/- female mice showed increased time spent in the open arms in an elevated plus maze test, reduction of locomotor activity and social interaction behavior, and decreased sucrose intake, when compared to WT female mice. In conclusion, these findings suggest that PUFAs-GPR40/FFAR1 signaling might function, at least in part, as a regulatory factor of emotional and maternal behavior in mice.