Cell cycle kinetics in the embryonic mouse corpus striatum

Abstract

Cells of the corpus striatum arise from the lateral ganglionic eminence of the telencephalic neuroepithelium. In mice, the length of the cell cycle and that of its component phases were estimated, and the interkinetic nuclear migratory pattern was characterized for lateral ganglionic progenitors on embryonic day 11 and 12 to gain insights into striatal cytogenetic process. An S-phase labeling paradigm using bromodeoxyuridine was employed. To assess regional variation in proliferative patterns, rostral, middle and caudal levels of the ganglionic neuroepithelium were examined separately. The pattern of interkinetic nuclear migration and the duration of G1-, G2-, and M-phases at the rostral and middle levels differed from those at the caudal level. The length of the cell cycle and that of the G1-phase increased during the interval embryonic day 11 to 12, especially at the rostral and middle levels. During the same interval, a sizable secondary proliferative population emerged at all three levels. Two principal conclusions are drawn: Progenitors at the different rostrocaudal levels are heterogeneous with regard to the pattern of cellular proliferation, and ganglionic progenitors are in advance of the cerebral cortical progenitors based on the relative size of the secondary proliferative population and the magnitude of cytokinetic parameters. Thus, proliferative behavior distinguishes progenitor populations at different rostrocaudal levels within the lateral ganglionic neuroepithelium and across the ganglionic and cerebral cortical domains of the telencephalic neuroepithelium.

Compartment-specific transcription factors orchestrate angiogenesis gradients in the embryonic brain

“…Thus, the periventricular networks are temporally and spatially well positioned to shape development of the incipient cortical radial units and guide tangential migration of GABA neurons 18,31 . Progression of the periventricular endothelial cell gradient coincides spatially and temporally with the appearance of mitotic figures in the telencephalic subventricular zone 45,46 , raising the possibility that the two events may be linked mechanistically. Finally, an unresolved issue in developmental neurobiology is how inductive morphogenetic gradients propagate over relatively long distances in the embryonic brain.…”

“…; Sigma) 2 h before death 45 . Embryos were removed and decapitated, and embryonic heads were immersed in zinc fixative (BD Pharmingen) for 24 h and processed for paraffin wax histology.…”

Homeobox genes Gsx1 and Gsx2 differentially regulate telencephalic progenitor maturation

“…The primary proliferative population (24,25) emerges in the VZ and as development proceeds, a secondary proliferative population (26,27) that occupies the SVZ arises, which adjoins the VZ. In the telencephalon, both VZ and SVZ cells are mitotically active progenitors (25,26). However, SVZ cells are progeny of VZ cells (28,29) and are thought to be more restricted in their developmental potential.…”

Elevated dopamine levels during gestation produce region-specific decreases in neurogenesis and subtle deficits in neuronal numbers

“…The brains were removed from the skull within an hour of decapitation, immersed in 70% ethanol overnight at room temperature and processed for paraffin-wax histology. We cut 4μm-thick sections of the paraffin-embedded brains in the coronal plane on a rotary microtome and processed the sections for BrdU immunohistochemistry using a monoclonal anti-BrdU antibody (Becton Dickenson, Mountain View, CA) and cobalt-nickel enhancement of diaminobenzidine reaction product [9,39,43,59]. The sections were stained with 0.1% aqueous basic fuchsin.…”