胚胎隔或隔＋蓝斑联合移植改善单侧穹窿伞损伤的老年大鼠空间记忆

AMELIORATION OF SPATIAL MEMORY IMPAIRMENT BY SEPTAL OR MIXED SEPTAL AND LOCUS COERULEUS TISSUE IN AGED RATS WITH UNILATERAL FIMBRIA-FORNIX TRANSECTION

对老年对照、单侧穹窿伞横断、穹窿伞横断＋隔移植及穹窿伞横断＋隔＋蓝斑联合移植等四组大鼠，在完全切断大鼠左侧穹窿伞后１０ｄ，将胚胎隔或隔＋蓝斑移植物的悬浮液注入损伤鼠双侧海马．１６周后分别用Ｍｏｒｒｉｓ水迷宫观察大鼠的学习记忆，用ＣｈＡＴ及ＴＨ染色观察移植物的生长，以ＡＣｈＥ染色观察宿主海马胆碱能纤维密度。结果表明：单侧穹窿伞横断不仅能严重地破坏大鼠的学习记忆功能，同时也使同侧海马的胆碱能纤维大量丧失；隔移植能改善损伤鼠的学习记忆功能，同时也使去胆碱能传入的海马重获胆碱能纤维的支配；隔＋蓝斑联合移植虽也能改善学习记忆功能，但作用不如隔移植，而且联合移植只提高损伤鼠海马ＣＡ１区胆碱能纤维密度，对ＣＡ３区及齿状回无作用，提示胚胎蓝斑不能协同隔移植物起作用。

Grafts of cholinergic-rich fetal tissue have been shown to ameliorate lesion-induced or age-dependent memory impairments of rats. Nevertheless, the recovery is only partial. This is not surprising, for the lesions such as fimbria-fornix transection deafferentates the dorsal hippocampus of nearly all other subcortieal connections besides the cbolinergic afferents. Nilssou established that combined graft of cbolinergic and serotonergic tissues was more effective than cholinergic tissue alone in ameliorating memory impairment of rats. The purpose of this article was to compere the effect of combined graft of cholinergic and noradrenergic tissues with cholinergic tissue alone on impaired spatial memory of aged rats. Thirty six aged male SD rats, weighting 450～550 g were divided into four groups-unilateral fimbria-fornix lesion, lesion plus septal graft, lesion plus combined septal and locus coeruleus tissues and control group. Ten days after unilateral fimbria-fornix transection, the fetal septal or mixed septal and locus coeruleus suspensions were implanted stereotaxically into bilateral hippocampi of lesioned rats. The rats were tested in the Morris water-maze task 16 weeks after transplantation. All surviving rats were killed and subjected to ChAT, TH and AChE stains. The results showed all aniseals had surviving grafts. The septal graft grew better than combined graft,The septal graft could recover the memory. impairment of lesioned rats, it also increased the AChE positive fiber densities in all CA1, CA3 areas and dentate gyrus of deafferent hippocampus. Although combihed graft could also ameliorate the behavior impairment,it did not do as well as septal alone, it only increased the fiber density in CA1 area.