THE EXPRESSION OF KAINATE RECEPTORS IN THE HIPPOCAMPUS OF MATERNAL SEPARATION RAT PUPS

Background Adverse experiences during early life such as social isolation, child abuse and parental loss is a significant risk factor for neuropsychiatric diseases such as cognitive deficits, anxiety disorders, and depression. Maternal Separation (MS) in rats during the early postnatal period, which is a well-established animal model of early life stress, is served as a model of psychopathology for anxiety disorders and depression. Methods To determine the molecular mechanism on the development of psychiatric problems following ELS, we assessed the alteration of molecules in the hippocampus of MS rats (during postnatal day 14–21) using microarray method. Results MS decreased the 59 genes and increased 23 genes more than two-fold. Interestingly, among them, we observed that the expressions of kainate receptor 1 (KA1) and 2 (KA2) genes were up-regulated in MS pups. This result was also confirmed by RT-PCR. Additionally, the immunoreactivities of KA1 and KA2 in the hippocampus were increased in the MS group compared to the control group. Discussion Our studies showed that MS-induced ELS induced the increased expressions of the hippocampal KA1 and KA2 receptors. These findings suggest that the alteration of glutamate system induced by ELS may be involved in the pathology of the psychiatric diseases such as depression and anxiety disorders.