Contribution of Rag1 to spatial memory ability in rats

Rag1 plays a critical role in the development and maturation of lymphocytes, and is related to immune memory functions. Deletion of Rag1 results in a lack of mature functional B and T lymphocytes. Rag1 transcription is most apparent in regions of the postnatal brain with high neuronal cell density--the cerebellum and the hippocampal formation, both of which are relevant to learning and memory function. In this research, three pairs of shRNA targeting Rag1 and a pair of scrambled sequences were constructed, packaged within a lentiviral vector system, and transferred into the cultured rat hippocampal neuron cells in vitro. Meanwhile, the lentivirus was injected stereotaxically into CA3 of the rat hippocampus, where the positive immunofluorescence for GFP expression was located. Rag1 mRNA expression was detected by RT-PCR 7, 14 and 28 days after stereotaxic injection. Assessment in the Morris water maze test 28 days post stereotaxic injection showed a loss of spatial learning and memory in the experimental rats. In long-term potentiation research, the experimental group did not display remarkable disparity in comparison with the control group. These findings indicate that the knockdown of Rag1 expression in the hippocampus may impair spatial learning and memory ability in rats.