Moser E I, Krobert K A, Moser M B, Morris R G
Department of Psychology, Norwegian University of Science and Technology, 7034 Trondheim, Norway.
Science. 1998 Sep 25;281(5385):2038-42. doi: 10.1126/science.281.5385.2038.
If information is stored as activity-driven increases in synaptic weights in the hippocampal formation, saturation of hippocampal long-term potentiation (LTP) should impair learning. Here, rats in which one hippocampus had been lesioned were implanted with a multielectrode stimulating array across and into the angular bundle afferent to the other hippocampus. Repeated cross-bundle tetanization caused cumulative potentiation. Residual synaptic plasticity was assessed by tetanizing a naïve test electrode in the center of the bundle. Spatial learning was disrupted in animals with no residual LTP (<10 percent) but not in animals that were capable of further potentiation. Thus, saturation of hippocampal LTP impairs spatial learning.
如果信息是以海马结构中由活动驱动的突触权重增加来存储的，那么海马长时程增强（LTP）的饱和应该会损害学习。在此，对一侧海马体受损的大鼠，在其另一侧海马体的角束传入纤维上植入一个多电极刺激阵列。重复进行跨束强直刺激会导致累积增强。通过对束中心一个未处理的测试电极进行强直刺激来评估残余的突触可塑性。在没有残余LTP（<10%）的动物中空间学习受到干扰，但在能够进一步增强的动物中则没有。因此，海马LTP的饱和会损害空间学习。
