Distribution Of Oxytocin In Male Brandt 's Voles And Mouse Brain Region And Its Effect On Social Behavior

Brandt’s voles, a kind of small rodent, in Inner Mongolia of China, belong to Rodentia, Myomorpha, Cricetidae, Arvicolinae, and Lasiopodomys. Brandt’s voles are herbivorous animals, which have strong reproductive ability. At present, there have been researches on the physiological, biochemical and immunological aspects of Brandt’s voles home and abroad.However, there were few reports on their embryo development and social behavior. Our group has long been devoted to the study of animalizationn of Brandt’s voles, comparatively analyzing the differences between Brandt’s voles and other experimental animals in many aspects, such as breed conservation, social behavior, endocrine and anatomy, in order to explore the potential medical application value of Brandt’s voles.4-month-old male and female Brandt’s voles were chosen to get sperm and eggs respectively in vitro. We analyzed and improved the effects of several common fertilization culture medias of rats and mice, including HTF, MTF, KSOM, mRlECM, mR2ECM, on in vitro fertilization of Brandt’s voles. As the results indicated, the sperm capacitation rate of Brandt’s voles fertilized in vitro was significantly increased after we added sorbitol solution to the basal culture medium of mRlECM and adjusted the concentration of Nacl to reduce the osmotic pressure of the culture medium to 260mOsm. During the early development of the fertilized egg, the embryo development ratewas higher when the fertilized eggs were transferred to mRlECM after 12hrs of incubation in the culture medium of KSOM than that of fertilized eggs transferred after24hours of incubation.2-month-old male Brandt’s voles and male BALB/c mice were chosen for the frozen brain serial sections.The differences in the expression of oxytocin between male Brandt’s voles and BALB/c mice were compared in several brain regions, which had been reported closely related to social behavior, including the paraventricular nucleus(PVN), medial preoptic area(MPOA), anterior hypothalamus(AH), lateral hypothalamus(LH) and medial amygdaloid nucleus(MeA)using immunohistochemical analysis. The results showed that there were differences in the distribution of oxytocin (OT)-stained cells in the brains of male Brandt’s voles and BALB/c mice.2-month-old male Brandt’s voles were chosen for a fixed point injection of lentiviral vector highly expressing oxytocin in the brain and a buried pipe injection of oxytocin receptor antagonists on the Medial amygdaloid (MeA), to increase or inhibit the function of oxytocin cells in the Medial amygdaloid (MeA). We test the social behavior of Brandt’s voles by using social interaction box. Results showed that both excessive expression and decreased expression of oxytocin distribution could inhibit the social behavior of Brandt’s voles.The differences in oxytocin levels in specific brain regions of male Brandt’s voles and BALB/c mice revealed the physiological basis for their differences in social behavior. The medial amygdaloid(MeA) oxytocin regulates the social recognition behavior of Brandt’s vole, which provides a theoretical basis for revealing the mechanism of oxytocin regulation in Brandt’s vole. This experiment lays the foundation for the study of Laboratory animal in Brandt’s voles.This experiment showed that the distribution of oxytocin in the Medial amygdaloid (MeA) would affect the social behavior of Brandt’s voles with a dose effect.