How Do Cortical Excitatory Neurons Terminate Their Migration at the Right Place? Critical Roles of Environmental Elements.

Yumiko Hatanaka,Tatsumi Hirata

doi:10.3389/fcell.2020.596708

Abstract

Interactions between neurons and their environment are crucial for proper termination of neuronal migration during brain development. In this review, we first introduce the migration behavior of cortical excitatory neurons from neurogenesis to migration termination, focusing on morphological and behavioral changes. We then describe possible requirements for environmental elements, including extracellular matrix proteins and Cajal–Retzius cells in the marginal zone, radial glial cells, and neighboring neurons, to ensure proper migration termination of these neurons at their final destinations. The requirements appear to be highly linked to sequential and/or concurrent changes in adhesiveness of migrating neurons and their surroundings, which allow the neurons to reach their final positions, detach from substrates, and establish stable laminar structures.

Highlights

The cerebral cortex is critical for memory formation, language, perception, attention, and other intellectual activities
We focus on the terminal phase of neuronal migration and discuss the role of these environmental components including extracellular matrix proteins and Cajal–Retzius (CR) cells in the marginal zone (MZ), radial glial (RG) cells, and neighboring neurons
Functionally blocking the molecules perturbs migration, sometimes leading to detachment of neurons from their RG fiber substrates in vitro (Anton et al, 1996, 1999) and in vivo (Elias et al, 2007). The distribution of these molecules has not been fully reported, these findings suggest that proper migration termination depends on the spatial distribution of RG adhesive molecules, and that a reduction of such molecules on RG fibers causes premature termination of neuronal migration (Figure 2B)

Summary

Introduction

The cerebral cortex is critical for memory formation, language, perception, attention, and other intellectual activities. Gil-Sanz et al (2013) showed that CR cells express an immunoglobulin-like cell adhesion molecule, Nectin1, while the leading processes of migrating cortical neurons express its preferred binding partner, Nectin3 (Figure 2A).

Results

Conclusion