Chen Yucui, Bourne Jennifer, Pieribone Vincent A, Fitzsimonds Reiko Maki
Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
Neuroreport. 2004 Apr 9;15(5):829-32. doi: 10.1097/00001756-200404090-00018.
Dendritic spines, which are the preferred site of excitatory synapses in the mammalian CNS, are actin-rich structures. We hypothesized that dynamic regulation of actin in spines would differentially affects processes that lead to potentiation vs depression of synaptic efficacy. Here, we report that the expression of long-term depression of excitatory synaptic transmission persists in the presence of actin polymerization in rat hippocampal slices. We observe that the reversal of LTD, de-depression, by high-frequency stimulation was completely blocked. Using electron microscopy, dramatic changes in dendritic spine morphology which accompany the sustained, irreversible depression of excitatory synaptic transmission were observed.
树突棘是哺乳动物中枢神经系统中兴奋性突触的首选位点，是富含肌动蛋白的结构。我们推测，树突棘中肌动蛋白的动态调节会对导致突触效能增强与减弱的过程产生不同影响。在此，我们报告，在大鼠海马切片中，兴奋性突触传递的长时程抑制（LTD）表达在肌动蛋白聚合存在的情况下持续存在。我们观察到，高频刺激导致的LTD反转，即去抑制，被完全阻断。使用电子显微镜观察到，伴随着兴奋性突触传递的持续、不可逆抑制，树突棘形态发生了显著变化。
