Hippocampus Of Rats With A Comparative Study Of Ectopic Cell Transplantation

Study on Comparison between Homotypic and Ectopic Transplantationof Fetal Hippocampal Field Grafts into Bilateral Ischemic-lesionedHippocampus in Adult ratsAbstractObjective:To evaluate the effects of transplantation of fetal hippocampal field grafts into the bilateral .bippocampal CAl region on hippocampal ischemic injury and elucidate which grafts can establish the fibrous connection of functional significance with recipient hippocampus.Methods:The model of ischemia in hippocampal CAl region was established with Pulsinelli-Brierley four vessel occlusion (4 VO) in adult rats. Then the ischemic rats were implanted with fetal tissue dissected from hippocampal CAl field and CA3 field, containing glutamatergic CAl and CA3 pyramidal cells respectively. The transplanted grafts in the adult rats were then observed and compared with behavioral, electrophysiological, histochemical and immunobistochemical methods. The adult rats with a total number of 90 were equally randomized into the CAl cell-grafted group (group A), CA3 cell-grafted group (group B), CAl non-active cell-grafted group (group C), ischemic group (group D) and control group (group E).Results:1. In group A, the grafted cells were survived in all the 18 animals. However, the cells were survived in only 12 animals in group B. The grafted cells grew in the manner of accumulation and mainly located in between the hippocampal alveus and lacunar molecule layer. Their morphology and size were similar to those of the pyramidal cells in CAl and CA3 regions in therecipient rats． p．In 6 weeks and3 mo血山s afterthetr山spl田uation,CAMMofthe ratsIn gro叩 A was not significantly different from that in gro呷 E(P＞0．05)．HoweveL ltwas signific团nlyd沥盯em fromthatingrowE InZ weeks afterthe transplanation(P＜0．05)．This index in grollps B,C and D wassignificantly different rom hat in gToop E(P＜0．05)． 3．In 2 weeks,6 weeks and 3 months after the transplanatlon,hehippocm叩d 0 rhythmhmand ltspower spectflllll were restored ingrow A bmnot In roaps B,Cand D． 4．In glollp A,P38 Inununolabeling density was Increaseawlth timeprolongation andreachedthe normal level In 6 weeks and 3 mo毗s狈er thetransplanation(P＞0．05)．No slgnlfican changes of this Index was found inother 4 grouP呷＞0．05)． 5．In gro叩 A,CA皿 of＊the rats was positively correlated to P38inununolabeling density In 2 weeks,6 weeks and 3 months after theransplantaion(r＝0．9961,P＜0．OD． Conclusion: l．The transpl出u叨 grafts offetal hlppoc孤叩d tissue can survive IntheCAI region oflschemlc－lesioned hlppoc聊us In adultrats and restore thedaxnaged behavioral and electtophyslologlcal讪ctlons of＊the recipienthlppoc帅usto certalndegree． 2．The mechanism of丘mctlonal restoration mlgN be dueto repair oflmurlous clrcultbutnot restoration oftransmltter system because both CAIand CA3 cells contain the sametfansmltter system． 3．Therestoratlon ofhlppocampal山ythmhm Indicates thatthe graftedcells mlgM have ibrous connection wlthreclplenthlppocampus andthere Isphysiologically functional Integration． 4．There exlststhe ununctlonal syn叩sol血egratlonbetweenthe grafted 互互亚 ") (cells and the recipient hippocampus.5.The quantitative analysis of hippocampal 0 rhythm and P38 expression can, to a certain degree, reflect the structural and functional integration between the grafted cells and recipient hippocampus. Therefore, these two indexes are of great value in evaluating the functional integration between the two after the transplantation with fetal hippocampal grafts.As a result, the comparison between isotopic and ectopic transplantation of fetal hippocampal grafts indicates that only the former canestablish the fibrous connection of functional...