A model and simulation research of NMDAª²depended bidirectional synaptic plasticity

    DONG Aiª²Rong, TAN Xiaoª²Dan, SU Yongª²Chun, GAO Tianª²Ming, DENG Qinª²Kai

    1Department of Medical Physics, 2Department of physiology, Southern Medical University, Guangzhou 510515, China

    ¡¾Astract¡¿ AIM: To study the correlative mechanism between the induction of long term modification and the activity of different NMDA receptor subtypes. METHODS: Based on the analysis of dynamic properties of NMDA receptor subtypes, an amended mathematical model of postsynaptic calcium was proposed to describe the relationship between different NMDA receptor subtype activity and presynaptic stimulus frequency. Along with a biochemicalª²reaction networks model of the postsynaptic Ca2+ª²depended signaling pathways, we developed a unified biophysical model about the hippocampal CA3ª²CA1 synapses bidirectional plasticity. RESULTS: According to the inductive condition of longª²term potentiation (LTP) and long term depression (LTD), our computer simulation mimicked the induction processes of NMDARª²dependent long term modification. CONCLUSION: It is elucidated that the calcium transients required for LTD may primarily come from the calcium inflow mediated by NR2B subtype channel of NMDA receptor and the induction of LTP may require the calcium inflow mediated by NR2B subtype channel. ......