Cassel J C, Kelche C, Will B
Département de Neurophysiologie et Biologie des Comportements, Centre de Neurochimie du C.N.R.S., Strasbourg, France.
Exp Brain Res. 1990;81(1):179-90. doi: 10.1007/BF00230114.
Based on three experiments, this study examined whether behavioral and histological effects of fetal septal or hippocampal grafts placed in the denervated hippocampus depend on the duration of post-grafting delays. Each experiment included four groups of rats: sham-operated rats (Sham), rats with aspirative lesions of the fimbria-fornix (Fifo) and rats given both Fifo lesions and intrahippocampal fetal suspension grafts of either septal (Fifo.ST) or hippocampal (Fifo.HT) origin. All rats were tested (i) for home cage activity, (ii) for activity and reactivity in an open field and (iii) for learning ability in a 8-arm radial maze. Except for home cage activity which was also monitored preoperatively, behavioral tests were conducted between 1-2 months postgrafting in Experiment 1 (EXP1), 5-6 months post-grafting in Experiment 2 (EXP2) and 10-11 months post-grafting in Experiment 3 (EXP3). Each test period lasted 3 weeks. Histological controls consisted of acetylcholinesterase (AChE) and cresyl violet staining. Graft size was estimated by computerized image analysis. Normal rats performed well in each experiment. In all experiments, rats with fimbria-fornix lesions showed increased activity in both their familiar (home cage) and unfamiliar (open field) environments, and their performances in the radial maze task were impaired. In no experiment did grafts, whether hippocampal or septal, affect "noncognitive" behavioral variables. However, maze performance was improved by hippocampal grafts in EXP1 (short delay) and by septal grafts in EXP2 (intermediate delay). No graft-induced effect was found in EXP3 (long delay). Concerning AChE-positivity in the dorsal hippocampus, fimbria-fornix lesions reduced staining densities by at least 60%. Both types of grafts were undiscernably AChE-positive, but only septal grafts provided the denervated hippocampus with a significant AChE-positive fiber ingrowth. Differences among groups in density of hippocampal AChE staining were comparable in all three experiments and no correlation between hippocampal AChE-positivity and maze performance was found. Our results suggest that graft-induced recovery from behavioral effects of fimbria-fornix lesions may depend on both the type of tissue implanted (hippocampal vs septal) and the post-grafting delay (1-2, 5-6 and 10-11 months). The recovery observed at a short post-grafting delay with hippocampal grafts and at a longer post-grafting delay with septal grafts was not persistent and concerned only cognitive function as assessed by radial maze performance.(ABSTRACT TRUNCATED AT 400 WORDS)
基于三项实验，本研究考察了置于去神经海马体中的胎儿隔区或海马体移植物的行为学和组织学效应是否取决于移植后延迟的时长。每项实验包括四组大鼠：假手术大鼠（假手术组）、接受穹窿海马伞抽吸损伤的大鼠（穹窿海马伞损伤组）以及既接受穹窿海马伞损伤又接受隔区（穹窿海马伞损伤/隔区移植组）或海马体（穹窿海马伞损伤/海马体移植组）来源的海马体内胎儿悬浮移植物的大鼠。所有大鼠均接受以下测试：（i）在饲养笼中的活动情况，（ii）在旷场中的活动及反应性，以及（iii）在八臂放射状迷宫中的学习能力。除了饲养笼中的活动在术前也进行监测外，行为学测试在实验1（EXP1）移植后1 - 2个月、实验2（EXP2）移植后5 - 6个月以及实验3（EXP3）移植后10 - 11个月进行。每个测试期持续3周。组织学对照包括乙酰胆碱酯酶（AChE）和甲酚紫染色。通过计算机图像分析估计移植物大小。正常大鼠在每项实验中表现良好。在所有实验中，穹窿海马伞损伤的大鼠在熟悉（饲养笼）和不熟悉（旷场）环境中的活动均增加，并且它们在放射状迷宫任务中的表现受损。在任何实验中移植物，无论是海马体还是隔区移植物，均未影响“非认知”行为变量。然而，在EXP1（短延迟）中，海马体移植物改善了迷宫表现，在EXP2（中等延迟）中，隔区移植物改善了迷宫表现。在EXP3（长延迟）中未发现移植物诱导的效应。关于背侧海马体中的AChE阳性，穹窿海马伞损伤使染色密度至少降低了60%。两种类型的移植物均有不可察觉的AChE阳性，但只有隔区移植物为去神经海马体提供了显著的AChE阳性纤维向内生长。在所有三项实验中，各组海马体AChE染色密度的差异具有可比性，并且未发现海马体AChE阳性与迷宫表现之间存在相关性。我们的结果表明，移植物诱导的从穹窿海马伞损伤的行为效应中恢复可能取决于植入组织的类型（海马体与隔区）以及移植后延迟（1 - 2个月、5 - 6个月和10 - 11个月）。在移植后短延迟时海马体移植物观察到的恢复以及在移植后长延迟时隔区移植物观察到的恢复并不持久，且仅涉及通过放射状迷宫表现评估的认知功能。（摘要截断于400字）
