Hou Qingming, Zhang Dawei, Jarzylo Larissa, Huganir Richard L, Man Heng-Ye
Department of Biology, Boston University, 5 Cummington Street, Boston, MA 02215, USA.
Proc Natl Acad Sci U S A. 2008 Jan 15;105(2):775-80. doi: 10.1073/pnas.0706447105. Epub 2008 Jan 3.
Homeostatic synaptic response is an important measure in confining neuronal activity within a narrow physiological range. Whether or not homeostatic plasticity demonstrates synapse specificity, a key feature characteristic of Hebbian-type plasticity, is largely unknown. Here, we report that in cultured hippocampal neurons, alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid subtype glutamate receptor (AMPAR) accumulation is increased selectively in chronically inhibited single synapses, whereas the neighboring normal synapses remain unaffected. This synapse-specific homeostatic regulation depends on the disparity of synaptic activity and is mediated by GluR2-lacking AMPARs and PI3-kinase signaling. These results demonstrate the existence of synaptic specificity and the crucial role of AMPAR-gated calcium in homeostatic plasticity in central neurons.
稳态突触反应是将神经元活动限制在狭窄生理范围内的一项重要指标。稳态可塑性是否表现出突触特异性（这是赫布型可塑性的一个关键特征）在很大程度上尚不清楚。在此，我们报告在培养的海马神经元中，α-氨基-3-羟基-5-甲基异恶唑-4-丙酸亚型谷氨酸受体（AMPAR）的积累在长期受抑制的单个突触中选择性增加，而相邻的正常突触则不受影响。这种突触特异性的稳态调节取决于突触活动的差异，并由缺乏GluR2的AMPAR和PI3激酶信号介导。这些结果证明了突触特异性的存在以及AMPAR门控钙在中枢神经元稳态可塑性中的关键作用。
