Regulation of spontaneous rhythmic activity and organization of pacemakers as memory traces by spike timing dependent synaptic plasticity in a hippocampal model英文电子书.pdf

PHYSICAL REVIEW E 69, 011910 2004 Regulation of spontaneous rhythmic activity and organization of pacemakers as memory traces by spike-timing-dependent synaptic plasticity in a hippocampal model Motoharu Yoshida1,* and Hatsuo Hayashi2,† 1 Department of Computer Science and Electronics, Graduate School of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka 820-8502, Japan 2Department of Brain Science and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Wakamatsu-ku, Kitakyushu 808-0196, Japan Received 9 May 2003; published 29 January 2004 It is widely believed that memory traces can be stored through synaptic conductance modification of dense excitatory recurrent connections ERCs in the hippocampal CA3 region, namely associative memory. ERCs, on the other hand, are crucial to maintain spontaneous rhythmic activity in CA3. Since it is experimentally suggested that synaptic conductances of ERCs are modified through spike-timing-dependent synaptic plasticity STDP, rhythmic activity might modify ERCs with the presence of STDP because rhythmic activity involves discharges of pyramidal cells. Memory patterns that are stored using ERCs might thus be modified or even destroyed. Rhythmic activity itself might also be modified. In this study, we assumed that the synaptic modi- fication in the hippocampal CA3 was subject to STDP, and examined the coexistence of memory traces and rhythmic activity. The activity of the network was dominated by radially propagating bur