Kano M, Hashimoto K, Kurihara H, Watanabe M, Inoue Y, Aiba A, Tonegawa S
Department of Physiology, Jichi Medical School, Minamikawachi-machi, Japan.
Neuron. 1997 Jan;18(1):71-9. doi: 10.1016/s0896-6273(01)80047-7.
Most of the cerebellar Purkinje cells (PCs) of an adult animal are innervated individually by a single climbing fiber (CF) that forms strong excitatory synapses with the PCs. This one-to-one relationship between a PC and a CF is a consequence of a developmentally regulated regression of the innervation of PCs by CFs. We found that, in mice deficient in the type 1 metabotropic glutamate receptor (mGluR1), the regression of supernumerary CFs ceases by the end of the second postnatal week, which is about one week earlier than in normal mice. Consequently, about one third of PCs in the mGluR1 mutant mice are innervated by multiple CFs in adulthood. We conclude that the regression of CFs normally occurs in two developmental phases and that mGluR1 plays a crucial role in the second phase.
成年动物的大多数小脑浦肯野细胞（PCs）由单个攀爬纤维（CF）单独支配，该攀爬纤维与浦肯野细胞形成强兴奋性突触。浦肯野细胞与攀爬纤维之间的这种一对一关系是攀爬纤维对浦肯野细胞支配在发育过程中受到调控的消退的结果。我们发现，在缺乏1型代谢型谷氨酸受体（mGluR1）的小鼠中，多余攀爬纤维的消退在出生后第二周结束时停止，这比正常小鼠早约一周。因此，成年mGluR1突变小鼠中约三分之一的浦肯野细胞由多个攀爬纤维支配。我们得出结论，攀爬纤维的消退通常发生在两个发育阶段，并且mGluR1在第二阶段起着关键作用。
