Zosimovskii V A, Korshunov V A
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia.
Neurosci Behav Physiol. 2010 Mar;40(3):315-23. doi: 10.1007/s11055-010-9258-8. Epub 2010 Feb 13.
Current concepts hold that during learning in waking animals, new information is transmitted from the neocortex to the hippocampus, where it leaves a temporary trace in the form of a mosaic of modified synapses. During sleep, reactivation of the neuron population initially activated by the new stimulus has the result that this information is returned to the neocortex, ensuring consolidation of a permanent memory trace. Exchange of information between the neocortex and hippocampal formation is mediated mainly by the entorhinal cortex, whose internal connections, in principle, allow "messages" from the output of the hippocampal formation to return to its inputs. Our experiments in awake and sleeping rabbits demonstrated that waves of excitation can return to hippocampal field CA1 and the dentate gyrus via fibers of the perforant path, these waves having initially entered field CA1 via potentiated synapses of Schäffer collaterals; during sleep, re-entrant waves of excitation reach a maximum and have a high probability of evoking discharges of dentate gyrus neurons. Thus, the new stimulus, potentiating synaptic connections in the hippocampus and, probably, the entorhinal cortex during waking, create conditions for reactivation of the corresponding hippocampal neuron populations during sleep by waves of excitation returning via the entorhinal cortex.
当前的观点认为，在清醒动物学习过程中，新信息从新皮层传递至海马体，在那里以修饰突触镶嵌体的形式留下临时痕迹。在睡眠期间，最初由新刺激激活的神经元群体重新激活，结果是该信息返回新皮层，确保永久记忆痕迹的巩固。新皮层与海马结构之间的信息交换主要由内嗅皮层介导，其内部连接原则上允许来自海马结构输出的“信息”返回其输入。我们对清醒和睡眠中的兔子进行的实验表明，兴奋波可通过穿通路径的纤维返回海马CA1区和齿状回，这些波最初是通过强化的谢弗侧支突触进入CA1区的；在睡眠期间，折返性兴奋波达到最大值，并且很可能诱发齿状回神经元放电。因此，新刺激在清醒时增强海马体以及可能还有内嗅皮层中的突触连接，通过经由内嗅皮层返回的兴奋波为睡眠期间相应海马神经元群体的重新激活创造了条件。
