Heat-shock pretreatment prevents suppression of long-term potentiation induced by scopolamine in rat hippocampal CA1 synapses.
We examined the effect of heat-shock pretreatment on long-term potentiation (LTP) in the CA1 hippocampal slices of the rat using the muscarinic blocker scopolamine as the LTP (memory) suppressor. Time course study using immunohistochemical techniques indicated peak expression of HSP70 16 h after heat-shock treatment. Focusing on that time point we found tetanic stimulation (at 100 Hz) induced LTP of 191.1+/-12.2% in control slices (n=7), which was suppressed by scopolamine to 114.5+/-2.8 %. Heat-shock pretreatment successfully prevented such suppression (216.6+/-38.2% and 190.2+/-10.6% with and without scopolamine, respectively, n=7). Both HSP expression and LTP responses were relatively small taken either 2 or 48 h after heat-shock or sham pretreatment. These results suggest that the induction of HSPs is time-dependent and can prevent scopolamine-mediated LTP suppression.
Lin
Yi-Wen
YW
Department of Physiology, National Yang-Ming University, Taipei 112, Taiwan, ROC.
Yang
Hsiu-Wen
HW
Min
Ming-Yuan
MY
Chiu
Tsai-Hsien
TH
D000818:Animals; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D018869:Heat-Shock Response / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D017729:Presynaptic Terminals / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012601:Scopolamine / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D018840:HSP70 Heat-Shock Proteins; D018727:Muscarinic Antagonists; D012601:Scopolamine