NMDA-BASED PATTERN-DISCRIMINATION IN A MODELED CORTICAL NEURON
NMDA-BASED PATTERN-DISCRIMINATION IN A MODELED CORTICAL NEURON
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DOI：
10.1162/neco.1992.4.4.502
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发表时间：
1992-07-01
影响因子：
2.9
通讯作者：
MEL, BW
中科院分区：
文献类型：
--
作者：
MEL, BW
对解剖学特征的皮质锥体细胞进行房室模拟，以研究复杂树突树的整合行为。先前的理论（Feldman 和 Ballard 1982；Durbin 和 Rumelhart 1989；Mel 1990；Mel 和 Koch 1990；Poggio 和 Girosi 1990）和区室建模（Koch 等人 1983；Shepherd 等人 1985；Koch 和 Poggio 1987；Rall 和 Segev 1987；Shepherd 和 Brayton 1987 年，谢泼德等人，1989 年； 1991）的工作表明，相邻突触组之间的乘法相互作用可以大大增强神经元相对于仅具有单个全局放电阈值的单元的处理能力。本文研究了这个问题，特别关注电压依赖性 N-甲基-D-天冬氨酸 (NMDA) 通道在细胞反应产生中的作用。首先，人们发现，当树突棘的大部分兴奋性突触输入由 NMDA 通道携带时，锥体细胞会优先对激活突触的空间聚集而非随机分布做出反应。其次，基于这种机制，富含 NMDA 的神经元被证明能够解决非线性模式辨别任务。我们提出，操纵树突轴上传入突触连接的空间顺序是学习过程中模式信息存储的一种可能的生物学策略。
Compartmental simulations of an anatomically characterized cortical pyramidal cell were carried out to study the integrative behavior of a complex dendritic tree. Previous theoretical (Feldman and Ballard 1982; Durbin and Rumelhart 1989; Mel 1990; Mel and Koch 1990; Poggio and Girosi 1990) and compartmental modeling (Koch et al. 1983; Shepherd et al. 1985; Koch and Poggio 1987; Rall and Segev 1987; Shepherd and Brayton 1987, Shepherd et al. 1989; Brown et al. 1991) work had suggested that multiplicative interactions among groups of neighboring synapses could greatly enhance the processing power of a neuron relative to a unit with only a single global firing threshold. This issue was investigated here, with a particular focus on the role of voltage-dependent N-methyl-D-asparate (NMDA) channels in the generation of cell responses. First, it was found that when a large proportion of the excitatory synaptic input to dendritic spines is carried by NMDA channels, the pyramidal cell responds preferentially to spatially clustered, rather than random, distributions of activated synapses. Second, based on this mechanism, the NMDA-rich neuron is shown to be capable of solving a nonlinear pattern discrimination task. We propose that manipulation of the spatial ordering of afferent synaptic connections onto the dendritic arbor is a possible biological strategy for pattern information storage during learning.