Stochastic resonance in the hippocampal CA3-CA1 model: a possible memory recall mechanism
Stochastic resonance in the hippocampal CA3-CA1 model: a possible memory recall mechanism
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DOI：
10.1016/s0893-6080(02)00092-8
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发表时间：
2002-12
期刊：
影响因子：
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通讯作者：
Motoharu Yoshida;H. Hayashi;K. Tateno;S. Ishizuka
中科院分区：
文献类型：
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作者：
Motoharu Yoshida;H. Hayashi;K. Tateno;S. Ishizuka
研究了海马区网络模型中的随机共振现象。海马区模型由CA3和CA1两层组成。CA3的锥体细胞通过Schaffer侧支突触与CA1的锥体细胞相连。CA3网络导致自发的不规则活动(宽带频谱峰值在3赫兹左右)，而CA1网络不会。CA3活性引起CA1锥体细胞膜电位波动。CA1网络还通过穿孔路径(PP)接收亚阈值信号(2.5或50赫兹)。亚阈值PP信号可以与作为噪声的膜电位波动一起激发CA1锥体细胞。CA1网络的触发表现出典型的SR特征。当PP信号的频率在伽马范围内(50赫兹)时，在本模型中发生的SR显示出明显的特征。CA1区锥体细胞的50赫兹放电受膜电位波动的调制，从而产生阵发性放电。CA1网络中的这种突发放电类似于在真实海马CA1中观察到的放电模式，提高了CA1中亚阈值信号检测的性能。此外，嵌入Schaffer侧支突触的记忆可以通过SR进行回忆。当CA1亚区的Schaffer侧支突触作为一种记忆模式增加三倍时，由于SR，亚区的锥体细胞对亚阈值PP信号做出反应，而CA1其余区域的锥体细胞不起作用。
Stochastic resonance (SR) in a hippocampal network model was investigated. The hippocampal model consists of two layers, CA3 and CA1. Pyramidal cells in CA3 are connected to pyramidal cells in CA1 through Schaffer collateral synapses. The CA3 network causes spontaneous irregular activity (broadband spectrum peaking at around 3Hz), while the CA1 network does not. The activity of CA3 causes membrane potential fluctuations in CA1 pyramidal cells. The CA1 network also receives a subthreshold signal (2.5 or 50Hz) through the perforant path (PP). The subthreshold PP signals can fire CA1 pyramidal cells in cooperation with the membrane potential fluctuations that work as noise. The firing of the CA1 network shows typical features of SR. When the frequency of the PP signal is in the gamma range (50Hz), SR that takes place in the present model shows distinctive features. 50Hz firing of CA1 pyramidal cells is modulated by the membrane potential fluctuations, resulting in bursts. Such burst firing in the CA1 network, which resembles the firing patterns observed in the real hippocampal CA1, improves performance of subthreshold signal detection in CA1. Moreover, memory embedded at Schaffer collateral synapses can be recalled by means of SR. When Schaffer collateral synapses in subregions of CA1 are augmented three-fold as a memory pattern, pyramidal cells in the subregions respond to the subthreshold PP signal due to SR, while pyramidal cells in the rest of CA1 do not fire.