Bagnall Martha W, Zingg Brian, Sakatos Alexandra, Moghadam Setareh H, Zeilhofer Hanns Ulrich, du Lac Sascha
University of California, San Diego, La Jolla, 92093, USA.
J Neurosci. 2009 Aug 12;29(32):10104-10. doi: 10.1523/JNEUROSCI.2087-09.2009.
The cerebellum funnels its entire output through a small number of presumed glutamatergic premotor projection neurons in the deep cerebellar nuclei and GABAergic neurons that feed back to the inferior olive. Here we use transgenic mice selectively expressing green fluorescent protein in glycinergic neurons to demonstrate that many premotor output neurons in the medial cerebellar (fastigial) nuclei are in fact glycinergic, not glutamatergic as previously thought. These neurons exhibit similar firing properties as neighboring glutamatergic neurons and receive direct input from both Purkinje cells and excitatory fibers. Glycinergic fastigial neurons make functional projections to vestibular and reticular neurons in the ipsilateral brainstem, whereas their glutamatergic counterparts project contralaterally. Together, these data suggest that the cerebellum can influence motor outputs via two distinct and complementary pathways.
小脑通过深部小脑核中少数假定的谷氨酸能运动前投射神经元以及反馈至下橄榄核的GABA能神经元输出其全部信息。在此，我们利用在甘氨酸能神经元中选择性表达绿色荧光蛋白的转基因小鼠，证明内侧小脑（顶核）中的许多运动前输出神经元实际上是甘氨酸能的，而非如先前认为的是谷氨酸能的。这些神经元表现出与相邻谷氨酸能神经元相似的放电特性，并接受来自浦肯野细胞和兴奋性纤维的直接输入。甘氨酸能顶核神经元向同侧脑干中的前庭和网状神经元发出功能性投射，而其谷氨酸能对应神经元则向对侧投射。这些数据共同表明，小脑可通过两条不同且互补的途径影响运动输出。
