The Solomon H. Snyder Department of Neuroscience, The Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore MD, USA.
Front Mol Neurosci. 2012 Feb 13;5:17. doi: 10.3389/fnmol.2012.00017. eCollection 2012.
Neurons possess diverse mechanisms of homeostatic adaptation to overall changes in neural and synaptic activity, which are critical for proper brain functions. Homeostatic regulation of excitatory synapses has been studied in the context of synaptic scaling, which allows neurons to adjust their excitatory synaptic gain to maintain their activity within a dynamic range. Recent evidence suggests that one of the main mechanisms underlying synaptic scaling is by altering the function of postsynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs), including synaptic expression of Ca(2+)-permeable (CP-) AMPARs. CP-AMPARs endow synapses with unique properties, which may benefit adaptation of neurons to periods of inactivity as would occur when a major input is lost. This review will summarize how synaptic expression of CP-AMPARs is regulated during homeostatic synaptic plasticity in the context of synaptic scaling, and will address the potential functional consequences of altering synaptic CP-AMPAR content.
神经元具有多种针对神经和突触活动整体变化的体内平衡适应机制,这对于正常的大脑功能至关重要。兴奋性突触的体内平衡调节在突触缩放的背景下进行了研究,突触缩放使神经元能够调整其兴奋性突触增益,以在动态范围内维持其活动。最近的证据表明,突触缩放的主要机制之一是通过改变突触后α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体 (AMPAR) 的功能,包括 Ca(2+)-可渗透 (CP-) AMPAR 的突触表达。CP-AMPAR 赋予突触独特的特性,这可能有助于神经元适应不活动期,就像主要输入丢失时一样。本综述将总结在突触缩放的背景下,CP-AMPAR 的突触表达如何在体内平衡突触可塑性过程中受到调节,并将讨论改变突触 CP-AMPAR 含量的潜在功能后果。