Bonilla-Quintana Mayte, Rangamani Padmini
Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093.
Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California 92093
eNeuro. 2024 Mar 11;11(3). doi: 10.1523/ENEURO.0497-23.2024. Print 2024 Mar.
Synaptic plasticity is important for learning and memory formation; it describes the strengthening or weakening of connections between synapses. The postsynaptic part of excitatory synapses resides in dendritic spines, which are small protrusions on the dendrites. One of the key features of synaptic plasticity is its correlation with the size of these spines. A long-lasting synaptic strength increase [long-term potentiation (LTP)] is only possible through the reconfiguration of the actin spine cytoskeleton. Here, we develop an experimentally informed three-dimensional computational model in a moving boundary framework to investigate this reconfiguration. Our model describes the reactions between actin and actin-binding proteins leading to the cytoskeleton remodeling and their effect on the spine membrane shape to examine the spine enlargement upon LTP. Moreover, we find that the incorporation of perisynaptic elements enhances spine enlargement upon LTP, exhibiting the importance of accounting for these elements when studying structural LTP. Our model shows adaptation to repeated stimuli resulting from the interactions between spine proteins and mechanical forces.
突触可塑性对于学习和记忆形成至关重要；它描述了突触之间连接的增强或减弱。兴奋性突触的突触后部分位于树突棘中，树突棘是树突上的小突起。突触可塑性的关键特征之一是其与这些树突棘大小的相关性。持久的突触强度增加[长期增强（LTP）]只有通过肌动蛋白树突棘细胞骨架的重新配置才有可能实现。在此，我们在移动边界框架中开发了一个基于实验的三维计算模型来研究这种重新配置。我们的模型描述了肌动蛋白与肌动蛋白结合蛋白之间导致细胞骨架重塑的反应及其对树突棘膜形状的影响，以研究LTP时树突棘的增大。此外，我们发现突触周围元件的纳入增强了LTP时树突棘的增大，这表明在研究结构性LTP时考虑这些元件的重要性。我们的模型显示出对由树突棘蛋白与机械力之间相互作用产生的重复刺激的适应性。
