突觸傳遞和調(diào)控lbppt課件-資料下載頁(yè)
2025-05-02 08:05本頁(yè)面
【正文】 A受體的轉(zhuǎn)運(yùn)上膜后才有大量功能性突觸的產(chǎn)生。研究者也習(xí)慣的把只含 NMDA受體的突觸定義為沉默突觸（ silent synapse）。 概念 暫時(shí) 沒(méi)有信息傳遞功能的突觸 Involvement of presynaptically or postsynaptically silent synapses in LTP maintenance. Presynaptic terminals contacting postsynaptic spines are schematically represented before and after LTP. (a) In presynaptically silent synapses (yellow) with low release probability (Pr) no responses can be detected before LTP (upper trace) in spite the expression of functional AMPARs and NMDARs on the subsynaptic membrane. After LTP, the increased Pr leads to the appearance of synaptic responses (after LTP, upper trace). In a synapse with low Pr (green) before LTP (lower trace), Pr can bee closer to 1 as a result of LTP induction so that no failures appear after LTP (lower trace). (b) In postsynaptically silent synapses, according to the latent AMPARs hypothesis (Malenka and Nicoll, 1999) before LTP, some synapses containing only NMDARs (yellow) are not active at resting membrane potential (upper trace). Insertion of new AMPARs makes the synapse conductive (after LTP, upper trace). Potentiation following insertion of new AMPARs may occur also in synapses previously effective (green). The hypothesis explains the decrease in failure rate in previously effective synapses suggesting fast addition of AMPAR clusters also in cases when the number of apparently silent synapses is small as in the hippocampus of adult animals. 沉默突觸的機(jī)制假說(shuō) 突觸前沉默的機(jī)制 突觸后沉默的機(jī)制 突觸后 AMPA NMDA Glu Glu Mg2+ 膜去極化 AMPA受體的作用機(jī)制 沉默突觸的功能是什么？ 作為腦學(xué)習(xí)記憶功能的一種能力儲(chǔ)備 謝謝大家
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