Dual synaptic plasticity in the hippocampus: Hebbian and spatiotemporal learning dynamics
Dual synaptic plasticity in the hippocampus: Hebbian and spatiotemporal learning dynamics
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DOI：
10.1007/s11571-008-9071-z
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发表时间：
2009-06
影响因子：
3.7
通讯作者：
Kimitaka Kaneki;O. Araki;M. Tsukada
中科院分区：
文献类型：
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作者：
Kimitaka Kaneki;O. Araki;M. Tsukada
我们假设海马神经元的突触可塑性机制涉及Hebbian学习动力学（HLD）和时空学习动力学（SLD）。虽然HLD是通过反向传播动作电位由突触前和突触后尖峰定时驱动的，但SLD仅由突触前尖峰定时诱发。由于反向传播衰减，因为它接近远端树突，我们假设一个极端的情况下，HLD只存在于近端树突和SLD只存在于远端树突的神经元模型。我们研究了突触权重如何在计算机模拟中响应于三种类型的突触输入而变化。首先，响应于具有恒定平均频率的泊松序列，HLD和SLD中的突触权重在性质上是相似的。第二，SLD比HLD对同步输入模式的响应更快，而每一个都对它们做出响应。第三，HLD对更频繁的输入响应更快，而SLD显示波动的突触权重。这些结果表明，在时空输入模式中的瞬时同步结构将通过SLD编码到远端树突中，并且持续同步或放电率信息将通过HLD编码到近端树突中。
We assume that Hebbian learning dynamics (HLD) and spatiotemporal learning dynamics (SLD) are involved in the mechanism of synaptic plasticity in the hippocampal neurons. While HLD is driven by pre- and postsynaptic spike timings through the backpropagating action potential, SLD is evoked by presynaptic spike timings alone. Since the backpropagation attenuates as it nears the distal dendrites, we assume an extreme case as a neuron model where HLD exists only at proximal dendrites and SLD exists only at the distal dendrites. We examined how the synaptic weights change in response to three types of synaptic inputs in computer simulations. First, in response to a Poisson train having a constant mean frequency, the synaptic weights in HLD and SLD are qualitatively similar. Second, SLD responds more rapidly than HLD to synchronous input patterns, while each responds to them. Third, HLD responds more rapidly to more frequent inputs, while SLD shows fluctuating synaptic weights. These results suggest an encoding hypothesis in that a transient synchronous structure in spatiotemporal input patterns will be encoded into distal dendrites through SLD and that persistent synchrony or firing rate information will be encoded into proximal dendrites through HLD.