Hippocampal Administration Of Ghrelin And Peripheral Injection Of AVP Improve The Spatial Learning And Memory In Rats

Objective: To investigate the effects of ghrelin and AVP on spatial learning and memory in rats and its mechanism in the central nervous system.Methods:â… . Food intake testâ…¡. Morris water maze tesâ…¢. Immunohistochemistry Results:1.Morris water maze task test: AVP sc 30min later, treated rats focused its search in the quadrant that formerly contained the platform.2. Food intake test: The difference of both the amount of accumulative of 24h food intake for one day and for consecutive 4 days between two groups treated with ghrelin and control group had no significance.3. Morris water maze task test: Rats treated with ghrelin of high dose displayed a shorter latency and swim distance to find the hidden platform compared with untreated animals. Treated rats focused its search in the quadrant that formerly contained the platform.4. Immuunohistochemistry revealed that treatment with ghrelin of high dose for 5 days significantly stimulated expression of NMDAR1, 2B in the dentate gyrus. Ghrelin also activated expression of c-Fos protein in the CA3 and dentate gyrus.Conclusion: Our test firstly detected the effect of ghrelin on spatial memory by Morris water maze. High levels of ghrelin(0.3nmol) in rodents can improve performance on memory and learning tasks. The positive effect on memory carried out maybe through activating expression of NMDAR1 and 2B in the dentate gyrus. In addition, it also perhaps increased the protein of long-term memory by activating expression of c-Fos in the CA3 and dentate gyrus and other areas.