coincident activity of converging pathways enables simultaneous long-term potentiation and long-term depression in hippocampal ca1 network in vivo重合的活动融合途径使同时长期势差和海马ca1网络体内的长期萧条.pdfVIP

Coincident Activity of Converging Pathways Enables Simultaneous Long-Term Potentiation and Long-Term Depression in Hippocampal CA1 Network In Vivo 1.¤ 1. 1 2 1,3 ZhiFang Dong , HuiLi Han , Jun Cao , Xia Zhang *, Lin Xu * 1 Key Laboratory of Animal Models and Human Disease Mechanisms, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, People’s Republic of China, 2 University of Ottawa Institute of Mental Health Research, Ottawa, Ontario, Canada, 3 Mental Health Institute, Second Xiangya Hospital of Central South University, Changsha, People’s Republic of China Abstract Memory is believed to depend on activity-dependent changes in the strength of synapses, e.g. long-term potentiation (LTP) and long-term depression (LTD), which can be determined by the sequence of coincident pre- and postsynaptic activity, respectively. It remains unclear, however, whether and how coincident activity of converging efferent pathways can enable LTP and LTD in the pathways simultaneously. Here, we report that, in pentobarbital-anesthetized rats, stimulation (600 pulses, 5 Hz) to Schaffer preceding to commissural pathway within a 40-ms timing window induced similar magnitudes of LTP in both pathways onto synapses of CA1 neurons, with varied LTP magnitudes after reversal of the stimulation sequence. In contrast, in urethane-anesthetized or freely-moving rats, the stimulation to Schaffer preceding to commissural pathway induced Schaffer LTP and commissural LTD simultaneously within a 40-ms timing window, without affecting synaptic efficacy in the reversed stimulation sequence. Coincident activity of Schaffer pathways confirmed the above findings under pentobarbital and urethane anesthesia. Thus, coincident activity of