Unilateral Lesion Of Dorsal Hippocampus In Adult Rats Impairs Contralateral Long-term Potentiation In Vivo And Spatial Memory In The Early Postoperative Phase

Object: To examine the influence of unilateral electrolytic dorsalhippocampal lesion in adult rats on contralateral LTP in vivo and spatialmemory during different postoperative phases, the electrolytic lesions’animal model were used to animal behavior test and electrophysiology invivo.Method: We here examined the influence of unilateral electrolyticdorsal hippocampal lesion in adult rats on contralateral LTP in vivo，spatialmemory in Morris water maze and open field paradigm during differentpostoperative phases (the behavior tests were not applied in acute group).Rats were divided into3groups: acute group,1-week group and4-weekgroup. In each group, half of the subjects received electrolytic lesions of thedorsal hippocampus, and the other half received sham surgery.Results: We found that acute unilateral hippocampal lesion had noeffect on contralateral LTP. However, contralateral LTP was impaired at1 week after lesion, and was restored to the control level at postoperative week4. Similarly, spatial memory was also impaired at postoperative week1, andwas restored at postoperative week4. In addition, the rats at postoperativeweek1showed stronger spatial exploratory behavior in a novel open-fieldenvironment. The sham operation had no effects on contralateral LTP, spatialmemory and exploration at either postoperative week1or week4.Conclusion: These results suggest that unilateral dorsal hippocampallesion in adult rats causes transient contralateral LTP impairment, spatialmemory deficit and novelty exploration abnormity.