Post-induction requirement of NMDA receptors for late phase long-term potentiation in vivo
作者单位：Institute of NeuroscienceState Key Laboratory of NeuroscienceShanghai Institutes for Biological SciencesChinese Academy of Sciences Division of NeurobiologyDepartment of Molecular and Cell BiologyUniversity of CaliforniaBerkeleyCA 94720-3200USA
会议名称：《中国神经科学学会第四次会员代表大会暨第八届全国学术会议》
会议日期：2009年
学科分类：0710[理学-生物学] 07[理学] 071006[理学-神经生物学]
关 键 词：L-LTP TBS time window LTP maintenance NMDA receptors spontaneous activity
摘 要：Objective Persistent activity-induced long-term synaptic potentiation or depression(LTP or LTD) is regarded as the cellular basis for developmental refinement of neural circuits and for learning and memory in the adult *** temporal development of LTP includes an early-phase LTP(E-LTP;lasting 1-2 h) and a late-phase LTP(L-LTP;lasting 3 h).However,the majority of our understanding on their properties and mechanisms comes from in vitro systems that are relatively silent concerning the spontaneous neural *** molecular and cellular mechanisms for the maintenance and reversal of LTP in the intact system with higher rate of natural spontaneous activities remain largely *** the present study,we have examined the consolidation of LTP at developing retinotectal synapses in Xenopus tadpoles in *** The field excitatory postsynaptic potentials(fEPSPs) were recorded in the tectum with a glass microelectrode filled with the HEPES-buffered bath saline,and its initial slope(20-80%of rising phase) is used to assay the long-term changes in the efficacy of developing retinotectal ***(1) Single episode of theta burst stimulation(TBS) to the optic nerve induced early-LTP of retinotectal synapses,lasting less than 1 h.(2) Three episodes of TBS with an optimal interval of 5 min(3×TBS-S5’) resulted in a robust and stable L-LTP lasting 3 h.(3) In addition to the established role of activation of N-methyl-D-aspartate(NMDA) receptors during the induction,NMDA receptor activation and the subsequent intracellular Ca increase in postsynaptic cells within a critical time window of 30 min following 3×TBS-S5’are also critically required for the stabilization of L-LTP in *** Our results suggest that the post-induction activation of NMDA receptors and Ca signaling in a limited time window following spaced patterns of synaptic activity are critical for the L-LTP maintenance in vivo.