Truncated TrkB-T1 regulates the morphology of neocortical layer I astrocytes in adult rat brain slices
Truncated TrkB-T1 regulates the morphology of neocortical layer I astrocytes in adult rat brain slices
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DOI：
10.1111/j.1460-9568.2007.05282.x
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发表时间：
2007-01-01
影响因子：
3.4
通讯作者：
Nakamura, Shun
中科院分区：
文献类型：
--
作者：
Ohira, Koji;Funatsu, Nobuo;Nakamura, Shun
通过改变其形态，星形胶质细胞，包括参与神经元的维持和可塑性以及清除递质的星形胶质细胞，在突触传递中发挥重要作用;然而，调节星形胶质细胞形态可塑性的机制仍不清楚。最近，我们报道了T1，TrkB（BDNF特异性受体家族）的一个亚型，通过控制原代星形胶质细胞培养物中的Rho GTPases改变星形胶质细胞的形态。在这项研究中，我们扩展了这一观察，以调查急性新皮层切片成年大鼠。将T1 siRNA表达载体电穿孔到活大鼠新皮层I层的星形胶质细胞中。在正常切片和对照载体电穿孔切片中，BDNF诱导星形胶质细胞突起的延长，并在孵育1小时后增加切片中突起的分支。相反，在T1 siRNA电穿孔切片中，在星形胶质细胞中没有观察到这种显著的形态学变化。此外，与GFAP（+）过程接触的突触体素（+）位点的数量以BDNF-T1依赖的方式增加，而总突触体素（+）位点没有增加。因此，本研究提供了证据的调节层I星形胶质细胞形态的BDNF-T1信号在成年大鼠新皮层切片。
By altering their morphology, astrocytes, including those involved in the maintenance and plasticity of neurons and in clearance of transmitter, play important roles in synaptic transmission; however, the mechanism that regulates the morphological plasticity of astrocytes remains unclear. Recently, we reported that T1, a subtype of TrkB (a family of BDNF-specific receptors), altered astrocytic morphology through the control of Rho GTPases in primary astrocyte cultures. In this study, we extended this observation to investigate acute neocortical slices from adult rats. T1 siRNA-expression vectors were electroporated into astrocytes in neocortical layer I of living rats. In both normal slices and control vector-electroporated slices, BDNF induced the elongation of the astrocytic processes and increased the branching of processes in slices after 1 h incubation. In contrast, in T1 siRNA-electroporated slices, no such significant morphological changes were observed in the astrocytes. In addition, the number of synaptophysin(+) sites in contact with GFAP(+) processes increased in a BDNF-T1-dependent manner without the increase in the total synaptophysin(+) sites. Therefore, the present study provides evidence of the regulation of layer I astrocytic morphology by the BDNF-T1 signal in adult rat neocortical slices.