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.
|Number of pages||5|
|Publication status||Published - 25 Sep 1998|
- Dentate Gyrus
- Electric Stimulation
- Electrodes, Implanted
- Evoked Potentials
- Excitatory Postsynaptic Potentials
- Long-Term Potentiation
- Maze Learning
- Perforant Pathway
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.