Cell Migration along the Lateral Cortical Stream to the Developing Basal Telencephalic Limbic System

Abstract

During embryogenesis, the lateral cortical stream (LCS) emerges from the corticostriatal border (CSB), the boundary between the developing cerebral cortex and striatum. The LCS is comprised of a mix of pallial-and subpallial-derived neural progenitor cells that migrate to the developing structures of the basal telencephalon, most notably the piriform cortex and amygdala. Using a combination of in vitro and in vivo approaches, we analyzed the timing, composition, migratory modes, origin, and requirement of the homeodomaincontaining transcription factor Gsh2 (genomic screened homeobox 2) in the development of this prominent migratory stream. We reveal that Pax6 (paired box gene 6)-positive pallial-derived and Dlx2 (distal-less homeobox 2)-positive subpallial-derived subpopulations of LCS cells are generated in distinct temporal windows during embryogenesis. Furthermore, our data indicate the CSB border not only is comprised of separate populations of pallial-and subpallial-derived progenitors that contribute to the LCS but also a subpopulation of cells coexpressing Pax6 and Dlx2. Moreover, despite migrating along a route outlined by a cascade of radial glia, the Dlx2-positive population appears to migrate primarily in an apparent chain-like manner, with LCS migratory cells being generated locally at the CSB with little contribution from other subpallial structures such as the medial, lateral, or caudal ganglionic eminences. We further demonstrate that the generation of the LCS is dependent on the homeodomain-containing gene Gsh2, revealing a novel requirement for Gsh2 in telencephalic development.

COUP-TFII controls amygdala patterning by regulating neuropilin expression

“…S6). It has been proposed that the migratory cells emerging from the pallialsubpallial boundary are the sources for basal telecephalon nuclei, such as the amygdala and piriform cortex (Stoykova et al, 2000;Toresson et al, 2000;Yun et al, 2001;Carney et al, 2006). Our data further demonstrate that the CGE, a subpallial progenitor zone, contributes cells to the BMA nucleus in the amygdala and COUP-TFII is essential for this process.…”

Delineation of Multiple Subpallial Progenitor Domains by the Combinatorial Expression of Transcriptional Codes

“…Interestingly, both domains may contribute to distinct populations of postmitotic neurons. Thus, pLGE1 appears to give rise primarily to postmitotic cells that maintain the expression of Pax6, whereas pLGE2 may contribute primarily to postmitotic neurons that maintain the expression of ER81 (Stenman et al, 2003a;Carney et al, 2006;Waclaw et al, 2006). The remaining part of the LGE VZ amplifies through a Dlx1/2 ϩ and Isl1 ϩ cell population in the SVZ and is likely to represent striatal progenitors (Stenman et al, 2003a).…”

Origin and Molecular Specification of Globus Pallidus Neurons

“…In the striatum, projection neurons appear to migrate radially from the LGE (Halliday and Cepko, 1992;Hamasaki et al, 2001), whereas interneurons reach their target from the MGE by tangential migration (Marín et al, 2000). Similarly, recent work has shown that the medial nucleus of the amygdala also forms by gathering radially migrating projection neurons from the LGE and tangentially migrating interneurons from the POA (Carney et al, 2006;Hirata et al, 2009).…”