Search results for "Ganglion mother cell"

Segment polarity and DV patterning gene expression reveals segmental organization of theDrosophilabrain

2003

The insect brain is traditionally subdivided into the trito-, deuto- and protocerebrum. However, both the neuromeric status and the course of the borders between these regions are unclear. The Drosophila embryonic brain develops from the procephalic neurogenic region of the ectoderm, which gives rise to a bilaterally symmetrical array of about 100 neuronal precursor cells, called neuroblasts. Based on a detailed description of the spatiotemporal development of the entire population of embryonic brain neuroblasts, we carried out a comprehensive analysis of the expression of segment polarity genes (engrailed, wingless, hedgehog, gooseberry distal,mirror) and DV patterning genes (muscle segmen…

Subventricular zone localized irradiation affects the generation of proliferating neural precursor cells and the migration of neuroblasts

2012

Radiation therapy is a part of the standard treatment for brain tumor patients, often resulting in irreversible neuropsychological deficits. These deficits may be due to permanent damage to the neural stem cell (NSC) niche, damage to local neural progenitors, or neurotoxicity. Using a computed tomography-guided localized radiation technique, we studied the effects of radiation on NSC proliferation and neuroblast migration in the mouse brain. Localized irradiation of the subventricular zone (SVZ) eliminated the proliferating neural precursor cells and migrating neuroblasts. After irradiation, type B cells in the SVZ lacked the ability to generate migrating neuroblasts. Neuroblasts from the u…

The Embryonic Central Nervous System Lineages ofDrosophila melanogaster

1996

In Drosophila, central nervous system (CNS) formation starts with the delamination from the neuroectoderm of about 30 neuroblasts (NBs) per hemisegment. They give rise to approximately 350 neurons and 30 glial cells during embryonic development. Understanding the mechanisms leading to cell fate specification and differentiation in the CNS requires the identification of the NB lineages. The embryonic lineages derived from 17 NBs of the ventral part of the neuroectoderm have previously been described (Bossing et al., 1996). Here we present 13 lineages derived from the dorsal part of the neuroectoderm and we assign 12 of them to identified NBs. Together, the 13 lineages comprise approximately …

Subventricular Zone-Derived Neuroblasts Migrate and Differentiate into Mature Neurons in the Post-Stroke Adult Striatum

2006

Recent studies have revealed that the adult mammalian brain has the capacity to regenerate some neurons after various insults. However, the precise mechanism of insult-induced neurogenesis has not been demonstrated. In the normal brain, GFAP-expressing cells in the subventricular zone (SVZ) of the lateral ventricles include a neurogenic cell population that gives rise to olfactory bulb neurons only. Herein, we report evidence that, after a stroke, these cells are capable of producing new neurons outside the olfactory bulbs. SVZ GFAP-expressing cells labeled by a cell-type-specific viral infection method were found to generate neuroblasts that migrated toward the injured striatum after middl…

Molecular markers for identified neuroblasts in the developing brain of Drosophila.

2003

The Drosophila brain develops from the procephalic neurogenic region of the ectoderm. About 100 neural precursor cells (neuroblasts) delaminate from this region on either side in a reproducible spatiotemporal pattern. We provide neuroblast maps from different stages of the early embryo (stages 9, 10 and 11, when the entire population of neuroblasts has formed), in which about 40 molecular markers representing the expression patterns of 34 different genes are linked to individual neuroblasts. In particular, we present a detailed description of the spatiotemporal patterns of expression in the procephalic neuroectoderm and in the neuroblast layer of the gap genes empty spiracles, hunchback, hu…

Differential effects of EGF receptor signalling on neuroblast lineages along the dorsoventral axis of the Drosophila CNS

1998

ABSTRACT The Drosophila ventral nerve cord derives from a stereotype population of about 30 neural stem cells, the neuroblasts, per hemineuromere. Previous experiments provided indications for inductive signals at ventral sites of the neuroectoderm that confer neuroblast identities. Using cell lineage analysis, molecular markers and cell transplantation, we show here that EGF receptor signalling plays an instructive role in CNS patterning and exerts differential effects on dorsoventral subpopulations of neuroblasts. The Drosophila EGF receptor (DER) is capable of cell autonomously specifiying medial and intermediate neuroblast cell fates. DER signalling appears to be most critical for prope…

2015

The clarification of complete cell lineages, which are produced by specific stem cells, is fundamental for understanding mechanisms, controlling the generation of cell diversity and patterning in an emerging tissue. In the developing Central Nervous System (CNS) of Drosophila, neural stem cells (neuroblasts) exhibit two periods of proliferation: During embryogenesis they produce primary lineages, which form the larval CNS. After a phase of mitotic quiescence, a subpopulation of them resumes proliferation in the larva to give rise to secondary lineages that build up the CNS of the adult fly. Within the ventral nerve cord (VNC) detailed descriptions exist for both primary and secondary lineag…

Neuroblast pattern and identity in the Drosophila tail region and role of doublesex in the survival of sex-specific precursors.

2013

The central nervous system is composed of segmental units (neuromeres), the size and complexity of which evolved in correspondence to their functional requirements. In Drosophila, neuromeres develop from populations of neural stem cells (neuroblasts) that delaminate from the early embryonic neuroectoderm in a stereotyped spatial and temporal pattern. Pattern units closely resemble the ground state and are rather invariant in thoracic (T1-T3) and anterior abdominal (A1-A7) segments of the embryonic ventral nerve cord. Here, we provide a comprehensive neuroblast map of the terminal abdominal neuromeres A8-A10, which exhibit a progressively derived character. Compared with thoracic and anterio…

The origin of postembryonic neuroblasts in the ventral nerve cord of Drosophila melanogaster.

1991

ABSTRACT Embryonic and postembryonic neuroblasts in the thoracic ventral nerve cord of Drosophila melanogaster have the same origin. We have traced the development of threefold-labelled single precursor cells from the early gastrula stage to late larval stages. The technique allows in the same individual monitoring of progeny cells at embryonic stages (in vivo) and differentially staining embryonic and postembryonic progeny within the resulting neural clone at late postembryonic stages. The analysis reveals that postembryonic cells always appear together with embryonic cells in one clone. Further-more, BrdU labelling suggests that the embryonic neuroblast itself rather than one of its proge…

The p21-activated kinase Mbt is a component of the apical protein complex in central brain neuroblasts and controls cell proliferation

2013

The final size of the central nervous system is determined by precisely controlled generation, proliferation and death of neural stem cells. We show here that the Drosophila PAK protein Mushroom bodies tiny (Mbt) is expressed in central brain progenitor cells (neuroblasts) and becomes enriched to the apical cortex of neuroblasts in a cell cycle- and Cdc42-dependent manner. Using mushroom body neuroblasts as a model system, we demonstrate that in the absence of Mbt function, neuroblasts and their progeny are correctly specified and are able to generate different neuron subclasses as in the wild type, but are impaired in their proliferation activity throughout development. In general, loss of…