Jacobs S, Cheng C, Doering L C
Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada.
Department of Pathology & Molecular Medicine, McMaster University, Hamilton, ON, Canada.
Neuroscience. 2016 Jun 2;324:202-17. doi: 10.1016/j.neuroscience.2016.03.011. Epub 2016 Mar 8.
Astrocytes are now recognized as key players in the neurobiology of neurodevelopmental disorders such as Fragile X syndrome. However, the nature of Fragile X astrocyte-mediated control of dendrite development in subtypes of hippocampal neurons is not yet known. We used a co-culture procedure in which wildtype primary hippocampal neurons were cultured with astrocytes from either a wildtype or Fragile X mouse, for either 7, 14 or 21 days. The neurons were processed for immunocytochemistry with the dendritic marker MAP2, classified by morphological criteria into one of five neuronal subtypes, and subjected to Sholl analyses. Both linear and semi-log methods of Sholl analyses were applied to the neurons in order to provide an in depth analysis of the dendritic arborizations. We found that Fragile X astrocytes affect the development of dendritic arborization of all subtypes of wildtype hippocampal neurons. Furthermore, we show that hippocampal neurons with spiny stellate neuron morphology exhibit the most pervasive developmental delays, with significant dendritic arbor alterations persisting at 21 days in culture. The results further dictate the critical role astrocytes play in governing neuronal morphology including altered dendrite development in Fragile X.
星形胶质细胞现在被认为是诸如脆性X综合征等神经发育障碍神经生物学中的关键参与者。然而，脆性X星形胶质细胞介导的对海马神经元亚型中树突发育的控制性质尚不清楚。我们采用了一种共培养方法，将野生型原代海马神经元与来自野生型或脆性X小鼠的星形胶质细胞共培养7天、14天或21天。对神经元进行免疫细胞化学处理，使用树突标记物MAP2，根据形态学标准将其分为五种神经元亚型之一，并进行Sholl分析。Sholl分析的线性和半对数方法都应用于神经元，以便对树突分支进行深入分析。我们发现脆性X星形胶质细胞会影响野生型海马神经元所有亚型的树突分支发育。此外，我们表明具有棘状星状神经元形态的海马神经元表现出最普遍的发育延迟，在培养21天时仍存在明显的树突分支改变。这些结果进一步表明星形胶质细胞在控制神经元形态包括脆性X中改变的树突发育方面发挥着关键作用。
