Freeman J N, Baisden R H, Woodruff M L
Department of Psychology, East Tennessee State University, Johnson City, USA.
Cell Transplant. 1995 Jan-Feb;4(1):113-22. doi: 10.1177/096368979500400115.
The results of previous studies indicated that block grafts of fetal hippocampal tissue made into cavities produced by aspiration lesions of the hippocampus in rats given the neurotoxin trimethyltin (TMT) significantly worsened the TMT-induced deficit in water maze acquisition. The purpose of the present study was to test the hypothesis that a procedure for transplantation that produced less destruction to the host brain and resulted in transplants with less mass might produce recovery in a spatial learning task in TMT-exposed rats. Acquisition of an externally cued (spatial) version of the radial arm maze (RAM), an internally cued version of the RAM, and of a differential reinforcement of low rate (DRL) operant schedule was assessed in normal rats, rats given TMT, and rats given TMT and stereotaxic implants of either fetal Ammon's horn or entorhinal cortex. The rats receiving Ammon's horn transplants made significantly fewer reentries into the baited arms in both maze configurations and fewer reentries into the nonbaited arms in the spatial RAM than rats in the TMT-only and TMT/entorhinal cortex transplant groups. The rats receiving transplants of Ammon's horn made significantly fewer responses and received more reinforcements during training on the DRL-20 schedule than rats receiving just TMT or rats receiving TMT and transplants of fetal entorhinal cortex. These results support the proposal that transplantation procedures that cause less damage to the host brain and result in transplants that do not occupy a large extent of the ventricular space increase the probability of behavioral recovery.
先前研究的结果表明，将胎儿海马组织块移植到由给予神经毒素三甲基锡（TMT）的大鼠海马体抽吸损伤所形成的空洞中，会显著加剧TMT诱导的水迷宫获取能力缺陷。本研究的目的是检验这样一种假设，即一种对宿主脑破坏较小且导致移植组织质量较小的移植程序，可能会使暴露于TMT的大鼠在空间学习任务中恢复。在正常大鼠、给予TMT的大鼠以及给予TMT并立体定向植入胎儿海马角或内嗅皮质的大鼠中，评估了放射状臂迷宫（RAM）的外部线索（空间）版本、RAM的内部线索版本以及低速率差异强化（DRL）操作程序的习得情况。与仅接受TMT的大鼠组和接受TMT及内嗅皮质移植的大鼠组相比，接受海马角移植的大鼠在两种迷宫构型中进入有诱饵臂的再次进入次数均显著减少，在空间RAM中进入无诱饵臂的再次进入次数也显著减少。在DRL - 20程序训练期间，接受海马角移植的大鼠比仅接受TMT的大鼠或接受TMT及胎儿内嗅皮质移植的大鼠做出的反应显著更少，且获得的强化更多。这些结果支持了这样的提议，即对宿主脑造成较小损伤且导致移植组织不占据很大脑室空间的移植程序会增加行为恢复的可能性。
