Müller T, Kettenmann H
Department of Neurobiology, University of Heidelberg, Germany.
Int Rev Neurobiol. 1995;38:341-59. doi: 10.1016/s0074-7742(08)60530-9.
While Bergmann glial cells play an important role in the development of the cerebellum they were thought to serve as passive insulators of the Purkinje cell dendritic tree and its synaptic connections. New results challenge this view and demonstrate that Bergmann glial cells are equipped with a large repertoire of receptors allowing them to sense the activity of synapses. These receptors have distinct biophysical and pharmacological features activating second-messenger pathways in the Bergmann glial cells. It is evident that the synapse has to be viewed as consisting of three elements, the presynaptic and postsynaptic region and the glial ensheathment. All three elements of this synaptic complex may undergo plastic changes as a prerequisite for central nervous system plasticity. Glial cells could interfere with synaptic transmission by communicating with neurons via the extracellular space, e.g., by modulating ion concentrations or transmitter levels in the cleft (Fig. 6).
虽然伯格曼胶质细胞在小脑发育中发挥着重要作用，但它们曾被认为是浦肯野细胞树突及其突触连接的被动绝缘体。新的研究结果对这一观点提出了挑战，并表明伯格曼胶质细胞配备了大量受体，使其能够感知突触的活动。这些受体具有独特的生物物理和药理学特性，可激活伯格曼胶质细胞中的第二信使途径。显然，突触必须被视为由三个部分组成，即突触前区域、突触后区域和胶质细胞包被。这种突触复合体的所有三个部分都可能发生可塑性变化，这是中枢神经系统可塑性的先决条件。胶质细胞可以通过细胞外空间与神经元进行通讯来干扰突触传递，例如通过调节突触间隙中的离子浓度或递质水平（图6）。
