Heterogeneous vestibulocerebellar mossy fiber projections revealed by single axon reconstruction in the mouse
Heterogeneous vestibulocerebellar mossy fiber projections revealed by single axon reconstruction in the mouse
复制标题
DOI：
10.1002/cne.24853
复制
发表时间：
2020-01-21
影响因子：
2.5
通讯作者：
Sugihara, Izumi
中科院分区：
文献类型：
--
作者：
Ando, Takahiro;Ueda, Mitsuhito;Sugihara, Izumi
前庭核中的大量神经元作为苔藓纤维（MF）投射到小脑，其参与姿势、眼-头运动和自主功能的控制和适应。然而，很少有人知道他们的轴突投射模式。用生物素化葡聚糖胺（BDA）标记前庭内侧核（MVN）神经元和初级传入神经元的单轴突，观察其形态学变化。MVN轴突（n = 35）分为三种类型的基础上，其主要的优势终止模式。Cbm型仅终止于小脑（15个轴突），而其他终止于小脑和对侧前庭核（cVN/Cbm型，13个轴突）或小脑和同侧前庭核（iVN/Cbm型，7个轴突）。Cbm型和cVN/Cbm型主要投射到结节和悬雍垂，与这些小叶中的纵纹没有任何明确的关系。它们常为双侧性的，有时也发出分支到小叶和其它的蚓小叶。iVN/Cbm型主要投射于同侧结节。不同类型的轴突在MVN内的分布不同。MF终端的一些vestibulocerebellar轴突，iVN/Cbm型轴突，特别是初级传入轴突的数量远远小于观察到的MF轴突起源于主要小脑前核和脊髓。结果表明，MVN神经元的异质性人口提供了不同的MF输入小脑。cVN/Cbm型和iVN/Cbm型表明，前庭核内的一些兴奋性神经元回路将其侧支作为MF供应给前庭小脑。
A significant population of neurons in the vestibular nuclei projects to the cerebellum as mossy fibers (MFs) which are involved in the control and adaptation of posture, eye-head movements, and autonomic function. However, little is known about their axonal projection patterns. We studied the morphology of single axons of medial vestibular nucleus (MVN) neurons as well as those originating from primary afferents, by labeling with biotinylated dextran amine (BDA). MVN axons (n = 35) were classified into three types based on their major predominant termination patterns. The Cbm-type terminated only in the cerebellum (15 axons), whereas others terminated in the cerebellum and contralateral vestibular nuclei (cVN/Cbm-type, 13 axons), or in the cerebellum and ipsilateral vestibular nuclei (iVN/Cbm-type, 7 axons). Cbm- and cVN/Cbm-types mostly projected to the nodulus and uvula without any clear relationship with longitudinal stripes in these lobules. They were often bilateral, and sometimes sent branches to the flocculus and to other vermal lobules. Also, the iVN/Cbm-type projected mainly to the ipsilateral nodulus. Neurons of these types of axons showed different distribution within the MVN. The number of MF terminals of some vestibulocerebellar axons, iVN/Cbm-type axons in particular, and primary afferent axons were much smaller than observed in previously studied MF axons originating from major precerebellar nuclei and the spinal cord. The results demonstrated that a heterogeneous population of MVN neurons provided divergent MF inputs to the cerebellum. The cVN/Cbm- and iVN/Cbm-types indicate that some excitatory neuronal circuits within the vestibular nuclei supply their collaterals to the vestibulocerebellum as MFs.