The cerebellum is involved in the coordination of movement. Its cellular composition is dominated by GABAergic neuronal types, and glial cells are known to express functional receptors. GABAergic signaling regulates cell proliferation, differentiation, and migration during neurodevelopment. However, little is known about the functional expression of GABA receptors in the cerebellar white matter (WM). Thus, the aim of this study was to test whether glial cells express functional GABA receptors during postnatal development (P7-P9) of cerebellar WM. Immunofluorescence showed that half of the astrocytes express GAD67, suggesting that glial cells synthesize GABA. Calcium imaging in cerebellar slices revealed that GABA and the GABA_A agonist muscimol evoked calcium transients in sulforhodamine B negative cells, whereas the GABA_B agonist baclofen failed to evoke responses in cerebellar WM. Whole-cell patch-clamp recordings of GFAP⁺ cells showed dye coupling and a passive current-voltage relation typical of astrocytes. Surprisingly, these cells did not respond to muscimol. Two additional populations were identified as GFAP^- cells. The first population showed dye coupling, slow decaying inward and outward currents with no voltage dependence, and did not respond to GABA_A agonists. The second population showed an outward-rectifying current-voltage relationship and responded to muscimol, but dye coupling was absent. These cells received synaptic input and were NG2⁺, but evoked calcium waves failed to modulate the frequency of spontaneous postsynaptic currents (sPSCs) or signaling into NG2 glia. We conclude that GABA_A receptor-mediated signaling is selective for NG2 glia in the WM of the cerebellum.

小脑参与运动的协调。它的细胞组成受GABA能神经元类型的控制，并且已知神经胶质细胞表达功能性受体。GABA能信号调节神经发育过程中的细胞增殖，分化和迁移。然而，关于小脑白质（WM）中GABA受体功能性表达的了解甚少。因此，本研究的目的是测试小脑WM的产后发育（P7-P9）过程中神经胶质细胞是否表达功能性GABA受体。免疫荧光显示一半的星形胶质细胞表达GAD67，表明神经胶质细胞合成GABA。小脑切片中的钙成像显示GABA和GABA _A激动剂muscimol引起磺基若丹明B阴性细胞中的钙瞬变，而GABA _B激动剂巴氯芬无法引起小脑WM中的反应。GFAP ⁺细胞的全细胞膜片钳记录显示了染料偶联和星形胶质细胞典型的无源电流-电压关系。令人惊讶的是，这些细胞对麝香酚没有反应。另外两个群体被确定为GFAP ^-细胞。第一批显示出染料偶联，缓慢衰减的内向和外向电流，而与电压无关，并且不响应GABA _A激动剂。第二种群显示出向外整流的电流-电压关系，并且对麝香酚有反应，但是没有染料偶联。这些细胞接受突触输入，为NG2⁺，但诱发的钙波未能调节自发突触后电流（sPSC）的频率或信号传导至NG2胶质细胞。我们得出的结论是，GABA _A受体介导的信号传导对小脑WM中的NG2胶质细胞具有选择性。