Cain D P, Hargreaves E L, Boon F, Dennison Z
Department of Psychology, University of Western Ontario, London, Canada.
Hippocampus. 1993 Apr;3(2):153-63. doi: 10.1002/hipo.450030208.
Two approaches were used to study the relations between the acquisition of place learning in the Morris water maze and long-term potentiation (LTP), kindling, and afterdischarge (AD). In the first, the possibility of behavioral LTP in the dentate gyrus field potential evoked by stimulation of the perforant path was evaluated in rats that showed robust place learning in the water maze. There was no effect of place learning on the field potential, and field potential measures did not correlate with place learning acquisition measures. In the second approach, the effect of bilateral saturation of LTP on subsequent place learning in the water maze task, begun within 5 minutes of the last LTP session, was evaluated. The effect of kindled seizures evoked bilaterally from the perforant path, or of a single unilateral AD, on acquisition of the water maze task (begun within 10 minutes) were also evaluated. Bilateral LTP saturation did not affect place learning, and the bilateral LTP group learned as readily as controls. In contrast, the kindled and AD groups were severely impaired in their performance of the place learning task. A second day of training in the water maze without any further electrical stimulation indicated that these groups had acquired considerable information on the first day of maze training and were not distinguishable from controls on the second day of training. This indicated that the deficit in these groups on the first day of training was temporary and likely resulted from a temporary perturbation of normal brain function due to the seizures. The results indicate that bilateral saturation of LTP in the dentate gyrus does not affect place learning in the water maze. They also indicate that recent hippocampal seizures, but not kindling, disrupt place learning in this task.
采用两种方法研究了在莫里斯水迷宫中位置学习的获得与长时程增强（LTP）、点燃和后放电（AD）之间的关系。第一种方法是，在水迷宫中表现出稳健位置学习能力的大鼠中，评估刺激穿通路径所诱发的齿状回场电位中的行为性LTP的可能性。位置学习对场电位没有影响，场电位测量结果与位置学习获得测量结果也不相关。在第二种方法中，评估了LTP双侧饱和对随后在水迷宫任务中位置学习的影响，该任务在最后一次LTP实验后5分钟内开始。还评估了从穿通路径双侧诱发的点燃性癫痫发作或单次单侧AD对水迷宫任务获得（在10分钟内开始）的影响。双侧LTP饱和不影响位置学习，双侧LTP组与对照组一样容易学习。相比之下，点燃组和AD组在位置学习任务的表现上严重受损。在水迷宫中进行第二天训练且没有任何进一步电刺激表明，这些组在迷宫训练的第一天已经获得了相当多的信息，并且在训练的第二天与对照组没有区别。这表明这些组在训练第一天的缺陷是暂时的，可能是由于癫痫发作导致正常脑功能的暂时扰动所致。结果表明，齿状回中LTP的双侧饱和不影响水迷宫中的位置学习。它们还表明，近期的海马癫痫发作而非点燃会破坏该任务中的位置学习。
