Glial Cell Development in the Spinal Cord from Ventricular Zone p1 Progenitors and V1 Cellular Precursors

Abstract

<p>The neural tube contains five classes of ventral neural progenitor domains (pO, pi, p2, pMN, and p3) which are induced at different locations in the neural tube based on the dorso-ventral gradient concentrations of Sonic Hedgehog and Bone Morphogenetic proteins (1). Each progenitor domain generates different types of ventral neurons of the spinal cord, including the motoneurons. The origins of glial cells are, however, not well established. It is thought that the majority of oligodendrocytes are derived from the motoneuron progenitor domain (pMN). In contrast, astrocytes are thought to derive from precursors of dorsal horn cells. Previous studies have shown that a small percent of oligodendrocytes and astrocytes can be derived by cells that express the transcription factor Dbx (2). This transcription, factor is also found in the ventral pi domain and their cellular derivatives. The pi domain produces Vi inhibitory interneurons, and these particular cells express a transcription factor known as Engrailed-l (Enl) when they become post-mitotic. This project proposes that some glial cells may also be derived from Vi precursors and therefore pi progenitors. To test this hypothesis, we used transgenic mice in which the cellular lineage of Vi engrailed-l expressing cells was labeled genetically with various reporter genes (mostly LacZ). In spinal cord secstiosn from these animals we then analyzed with immunocytochemistry the expression in Vi cells of markers of oligodendrocytes or astrocytes at various stages of maturation. The results show that some spinal cord glial cells are in fact derived from Vi cells. Future experiments will determine the mechanism that switches the cellular fates of Vi cells from neural to glial.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>