The fornix acts as a permissive corridor for septal neuron migration beyond the diencephalic-telencephalic boundary.
The fornix acts as a permissive corridor for septal neuron migration beyond the diencephalic-telencephalic boundary.
复制标题
穹窿充当间隔神经元迁移到间脑-端脑边界之外的许可走廊。
DOI：
10.1038/s41598-020-65284-7
复制
发表时间：
2020
影响因子：
4.6
通讯作者：
Sato N.
中科院分区：
文献类型：
--
作者：
Watanabe K;Takebayashi H;Sato N.
神经元迁移是构造功能神经网络的关键。两个后隔（PS）核，三角隔核和床核的前连合，涉及恐惧和焦虑。在发育过程中，海马能PS神经元从间脑的丘脑隆起（TE）向吻背侧长距离迁移，然后定居于端脑的尾侧。然而，PS神经元的发育行为以及促进其迁移的引导结构仍然未知。我们以前证明了PS神经元沿着穹窿迁移，这是海马结构的主要传出通路。在这里，我们表明，postcommissural穹窿是必不可少的PS神经元迁移，这在很大程度上是局限于其轴突束，在相反的方向生长的PS神经元迁移。穹窿轴突在PS神经元吻背迁移开始之前到达TE。脑信号蛋白3A在背内侧皮质的异位表达导致穹窿形成缺陷。此外，失去后连合穹窿停滞PS神经元迁移导致异常积累附近的起源。这表明，PS神经元利用后连合穹窿作为一个允许的走廊迁移超过间脑-端脑边界。这种轴突的支持是必不可少的异质隔核复合体的功能组织。
Neuronal migration is essential for constructing functional neural networks. Two posterior septal (PS) nuclei, the triangular septal nucleus and bed nuclei of the anterior commissure, are involved in fear and anxiety. During development, glutamatergic PS neurons undergo long-distance rostrodorsal migration from the thalamic eminence (TE) of the diencephalon, then settle in the caudalmost telencephalon. However, the developmental behavior of PS neurons and the guidance structures facilitating their migration remain unknown. We previously demonstrated the migration of PS neurons along the fornix, a major efferent pathway from the hippocampal formation. Here, we show that the postcommissural fornix is essential for PS neuron migration which is largely confined to its axonal tract, which grows in the opposite direction as PS neuron migration. Fornical axons reach the TE prior to initiation of PS neuron rostrodorsal migration. Ectopic expression of Semaphorin 3 A in the dorsomedial cortex resulted in defective fornix formation. Furthermore, loss of the postcommissural fornix stalled PS neuron migration resulting in abnormal accumulation near their origin. This suggests that PS neurons utilize the postcommissural fornix as a permissive corridor during migration beyond the diencephalic-telencephalic boundary. This axonal support is essential for the functional organization of the heterogeneous septal nuclear complex.