Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA.
Phys Rev E. 2022 Jun;105(6-1):064407. doi: 10.1103/PhysRevE.105.064407.
The lateral diffusion and trapping of neurotransmitter receptors within the postsynaptic membrane of a neuron play a key role in determining synaptic strength and plasticity. Trapping is mediated by the reversible binding of receptors to scaffolding proteins (slots) within a synapse. In this paper we introduce a method for analyzing the transient dynamics of proximal axodendritic synapses in a diffusion-trapping model of receptor trafficking. Given a population of spatially distributed synapses, each of which has a fixed number of slots, we calculate the rate of relaxation to the steady-state distribution of bound slots (synaptic weights) in terms of a set of local accumulation times. Assuming that the rates of exocytosis and endocytosis are sufficiently slow, we show that the steady-state synaptic weights are independent of each other (purely local). On the other hand, the local accumulation time of a given synapse depends on the number of slots and the spatial location of all the synapses, indicating a form of transient heterosynaptic plasticity. This suggests that local accumulation time measurements could provide useful information regarding the distribution of synaptic weights within a dendrite.
神经递质受体在神经元突触后膜中的横向扩散和捕获在决定突触强度和可塑性方面起着关键作用。捕获是通过受体与突触内支架蛋白（插槽）的可逆结合来介导的。在本文中，我们介绍了一种在受体运输扩散捕获模型中分析近侧轴突树突突触瞬态动力学的方法。对于一个具有固定数量插槽的空间分布的突触群体，我们根据一组局部累积时间来计算绑定插槽（突触权重）的稳态分布的松弛速率。假设胞吐作用和胞吞作用的速率足够慢，我们表明稳态突触权重彼此独立（纯粹是局部的）。另一方面，给定突触的局部累积时间取决于插槽的数量和所有突触的空间位置，这表明存在一种瞬时异突触可塑性。这表明局部累积时间测量可能提供有关树突内突触权重分布的有用信息。
