Yip Yee Ping, Capriotti Christine, Yip Joseph W
Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
J Comp Neurol. 2003 May 19;460(1):94-105. doi: 10.1002/cne.10634.
Our previous study showed that the migration of sympathetic preganglionic neurons (SPN) in the spinal cord is affected in the reeler mutant. The present study, using morphometric analysis to describe and compare the location of SPN at progressive developmental stages, provides detailed information on how SPN migrate in the presence or absence of the reelin gene. We found that the initial migration (prior to E11.5) of SPN from the neuroepithelium to the ventrolateral spinal cord is similar in both control (wild-type and heterozygous) and reeler mice. However, as development progressed (E12.5-E15.5), SPN in control mice migrated dorsally toward the intermediate lateral spinal cord region, where 80% settled to form the intermediolateral column (IML); the rest migrated medially to locations between the IML and the central canal. In reeler, 80% of SPN migrated dorsomedially to cluster around the central canal, with the rest distributed between the central canal and the intermediate lateral spinal cord region. The present study also examined the relationship among SPN, Reelin, and radial glial fibers in control and reeler mice. Confocal microscopic studies showed that during their initial migration, SPN in both control and reeler mice were closely apposed to radial glial fibers in the ventrolateral spinal cord. The majority of SPN in control mice then migrated dorsolaterally, in a direction perpendicular to radial glial fibers, to form the IML. In contrast, the majority of SPN in reeler migrated in the same orientation as radial glial fibers back toward the central canal, instead of migrating dorsolaterally to form the IML. A possible explanation for these results is that Reelin acts to prevent SPN from back-migration on radial glial fibers toward the central canal.
我们之前的研究表明，在reeler突变体中，脊髓中交感神经节前神经元（SPN）的迁移受到影响。本研究通过形态计量分析来描述和比较SPN在发育各阶段的位置，提供了关于在有或无reelin基因情况下SPN如何迁移的详细信息。我们发现，在对照（野生型和杂合子）小鼠和reeler小鼠中，SPN从神经上皮向脊髓腹外侧的初始迁移（E11.5之前）是相似的。然而，随着发育进程（E12.5 - E15.5），对照小鼠中的SPN向背侧迁移至脊髓中间外侧区域，其中80%定居形成中间外侧柱（IML）；其余的向内侧迁移至IML与中央管之间的位置。在reeler小鼠中，80%的SPN向背内侧迁移并聚集在中央管周围，其余的分布在中央管与脊髓中间外侧区域之间。本研究还检测了对照小鼠和reeler小鼠中SPN、Reelin和放射状胶质纤维之间的关系。共聚焦显微镜研究显示，在初始迁移过程中，对照小鼠和reeler小鼠中的SPN都与脊髓腹外侧的放射状胶质纤维紧密相邻。对照小鼠中的大多数SPN随后向背外侧迁移，方向垂直于放射状胶质纤维，以形成IML。相比之下，reeler小鼠中的大多数SPN与放射状胶质纤维同向迁移，返回中央管，而不是向背外侧迁移形成IML。这些结果的一个可能解释是，Reelin的作用是防止SPN在放射状胶质纤维上向中央管反向迁移。
