Annis C M, O'Dowd D K, Robertson R T
Department of Anatomy and Neurobiology, University of California, Irvine 92717.
J Neurobiol. 1994 Dec;25(12):1483-93. doi: 10.1002/neu.480251202.
In order to examine the effects of activity on spine production and/or maintenance in the cerebral cortex, we have compared the number of dendritic spines on pyramidal neurons in slices of P0 mouse somatosensory cortex maintained in organotypic slice cultures under conditions that altered basal levels of spontaneous electrical activity. Cultures chronically exposed to 100 microM picrotoxin (PTX) for 14 days exhibited significantly elevated levels of electrical activity when compared to neurons in control cultures. Pyramidal neurons raised in the presence of PTX showed significantly higher densities of dendritic spines on primary apical, secondary apical, and secondary basal dendrites when compared to control cultures. The PTX-induced increase in spine density was dose dependent and appeared to saturate at 100 microM. Cultures exhibiting little or no spontaneous activity, as a result of growth in a combination of PTX and tetrodotoxin (TTX), showed significantly fewer dendritic spines compared to cultures maintained in PTX alone. These results demonstrate that the density of spines on layers V and VI pyramidal neurons can be modulated by growth conditions that alter the levels of spontaneous electrical activity.
为了研究活动对大脑皮质中树突棘产生和/或维持的影响，我们比较了在改变自发电活动基础水平的条件下，培养于器官型脑片培养物中的P0小鼠体感皮质脑片中锥体细胞上的树突棘数量。与对照培养物中的神经元相比，长期暴露于100微摩尔匹鲁卡品（PTX）14天的培养物表现出显著升高的电活动水平。与对照培养物相比，在PTX存在下培养的锥体细胞在初级顶树突、次级顶树突和次级基底树突上显示出显著更高的树突棘密度。PTX诱导的树突棘密度增加呈剂量依赖性，并且在100微摩尔时似乎达到饱和。由于在PTX和河豚毒素（TTX）组合中生长而几乎没有或没有自发活动的培养物，与仅在PTX中培养的培养物相比，显示出明显更少的树突棘。这些结果表明，V层和VI层锥体细胞上的树突棘密度可通过改变自发电活动水平的生长条件来调节。
