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Local establishment of repetitive long‐term potentiation‐induced synaptic enhancement in cultured hippocampal slices with divided input pathways
Author(s) -
Oe Yuki,
TominagaYoshino Keiko,
Ogura Akihiko
Publication year - 2011
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.22668
Subject(s) - long term potentiation , neuroscience , synaptic plasticity , hippocampus , hippocampal formation , tetanic stimulation , ltp induction , biology , chemistry , excitatory postsynaptic potential , inhibitory postsynaptic potential , biochemistry , receptor
Long‐term potentiation (LTP) in the rodent hippocampus is a popular model for synaptic plasticity, which is considered the cellular basis for brain memory. Because most LTP analysis involves acutely prepared brain slices, however, the longevity of single LTP has not been well documented. Using stable hippocampal slice cultures for long‐term examination, we previously found that single LTP disappeared within 1 day. In contrast, repeated induction of LTP led to the development of a distinct type of plasticity that lasted for more than 3 weeks and was accompanied by the formation of new synapses. Naming this novel plastic phenomenon repetitive LTP‐induced synaptic enhancement (RISE), we proposed it as a model for the cellular processes involved in long‐term memory formation. However, because in those experiments LTP was induced pharmacologically in the whole slice, it is not known whether RISE has input‐pathway specificity, an essential property for memory. In this study, we divided the input pathway of CA1 pyramidal neurons by a knife cut and induced LTP three times, the third by tetanic stimulation in one of the divided pathways to express RISE specifically. Voltage‐sensitive dye imaging andGolgi‐staining performed 2 weeks after the three LTP inductions revealed both enhanced synaptic strength and increased dendritic spine density confined to the tetanized region. These results demonstrate that RISE is a feasible cellular model for long‐term memory. © 2011 Wiley‐Liss, Inc.