Information transfer may not be limited only to synapses. Therefore, the processes and dynamics of biological neuron-astrocyte coupling and intercellular interaction within this domain are worth investigating. Existing models of tripartite synapse consider an astrocyte as a point process. Here, we extended the tripartite synapse model by considering the astrocytic processes (synaptic and perinodal) as compartments. The scattered extrinsic signals in the extracellular space and the presence of calcium stores in different astrocytic sites create local transient [Ca²⁺]. We investigated the Ca²⁺ dynamics and found that the increase in astrocytic intracellular [Ca²⁺] enhances the probability of neurotransmitter release. However, the period in which the extrasynaptic glutamate lingers in the extracellular space may cause excitotoxicity. We propose further biological investigation on intercellular communication, considering that unconventional sources (nonsynaptic) of glutamate may improve information processing in neuron-astrocyte networks.

中文翻译：

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三元突触与perinodal星形细胞过程的时空模型。

信息传递可能不仅限于突触。因此，在该域内生物学神经元-星形细胞偶联和细胞间相互作用的过程和动力学值得研究。现有的三方突触模型将星形胶质细胞视为一个点过程。在这里，我们通过考虑星形胶质细胞过程（突触和perinodal）作为隔室扩展了三方突触模型。细胞外空间中分散的外部信号以及不同星形细胞位点中钙储存的存在会产生局部瞬时[Ca ²⁺ ]。我们调查了Ca ^2+的动力学，发现星形细胞的细胞内[Ca ²⁺]增加了神经递质释放的可能性。但是，突触外谷氨酸在细胞外空间停留的时间段可能引起兴奋性毒性。考虑到谷氨酸的非常规来源（非突触）可改善神经元-星形细胞网络中的信息处理，我们建议对细胞间通讯进行进一步的生物学研究。