Kano M, Hashimoto K, Chen C, Abeliovich A, Aiba A, Kurihara H, Watanabe M, Inoue Y, Tonegawa S
Department of Physiology, Jichi Medical School, Tochigi-ken, Japan.
Cell. 1995 Dec 29;83(7):1223-31. doi: 10.1016/0092-8674(95)90147-7.
PKC gamma is highly expressed in Purkinje cells (PCs) but not in other types of neurons in the cerebellum. The expression of PKC gamma changes markedly during cerebellar development, being very low at birth and reaching a peak around the third postnatal week. This temporal pattern of PKC gamma expression coincides with the developmental transition from multiple to single climbing fiber innervation onto each PC. In adult mutant mice deficient in PKC gamma, we found that 41% of PCs are still innervated by multiple climbing fibers, while other aspects of the cerebellum including the morphology and excitatory synaptic transmission of PCs appear normal. Thus, elimination of multiple climbing fiber innervation appears to be specifically impaired in the mutant cerebellum. We suggest that the developmental role of PKC gamma may be to act as a downstream element in the signal cascade necessary for the elimination of surplus climbing fiber synapses.
蛋白激酶Cγ（PKCγ）在浦肯野细胞（PCs）中高度表达，但在小脑的其他类型神经元中不表达。PKCγ的表达在小脑发育过程中显著变化，出生时非常低，在出生后第三周左右达到峰值。PKCγ表达的这种时间模式与每个PC从多条攀缘纤维支配到单条攀缘纤维支配的发育转变相吻合。在缺乏PKCγ的成年突变小鼠中，我们发现41%的PCs仍然由多条攀缘纤维支配，而小脑的其他方面，包括PCs的形态和兴奋性突触传递，看起来是正常的。因此，在突变的小脑中，多条攀缘纤维支配的消除似乎受到了特异性损害。我们认为，PKCγ在发育中的作用可能是作为消除多余攀缘纤维突触所需信号级联中的下游元件。
