The strength of each excitatory synapse in the central nervous system is regulated by its prior activity in a process called synaptic plasticity. The initiation of synaptic plasticity occurs when calcium ions enter the postsynaptic compartment and encounter a subcellular structure called the postsynaptic density (PSD). The PSD is attached to the postsynaptic membrane just underneath the concentrated plaque of neurotransmitter receptors. It is comprised of a core set of 30–60 proteins, approximately 20 of which are scaffold proteins. The rest include protein kinases and phosphatases, some of which respond to calcium ion; small GTPases and their regulators; chaperones; ubiquitins; and proteases. The assembly of the PSD involves competitive binding among a variety of specific protein binding sites to form a dynamic network. A biochemical challenge for the future is to understand how the dynamic regulation of the structure, composition, and activity of the PSD mediates synaptic plasticity and how mutations in PSD proteins lead to mental and neurodegenerative diseases.

中文翻译：

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谷氨酸突触突触后密度的蛋白质生物化学介导神经网络的学习

中枢神经系统中每个兴奋性突触的强度由其先前的活动调节，这一过程称为突触可塑性。当钙离子进入突触后区室并遇到称为突触后密度（PSD）的亚细胞结构时，突触可塑性开始发生。PSD 附着在神经递质受体集中斑块下方的突触后膜上。它由 30-60 个蛋白质组成的核心组组成，其中大约 20 个是支架蛋白。其余包括蛋白激酶和磷酸酶，其中一些对钙离子有反应；小 GTP 酶及其调节剂；伴侣; 泛素；和蛋白酶。PSD 的组装涉及各种特定蛋白质结合位点之间的竞争性结合，形成动态网络。未来的生化挑战是了解 PSD 的结构、组成和活性的动态调节如何介导突触可塑性，以及 PSD 蛋白的突变如何导致精神和神经退行性疾病。