Developing Mouse Cerebral Cortex Research Articles

Top row from the left: DAPI staining of a tadpole larvae of the ascidian, Halocynthia roretzi, see Yamada and Nishida, 376–386. Developing mouse cortex consisting with neural progenitor cells positive for Pax6 (magenta) and neurons marked with Tuj1 (green), see Tsunekawa et al., 349–357. Histograms of DNA content per nucleus of mouse cardiomyocytes (mono‐ and binucleate cells) during postnatal stages,

Development, Growth & DifferentiationVolume 56, Issue 5 p. i-i Cover ImageFree Access Top row from the left: DAPI staining of a tadpole larvae of the ascidian, Halocynthia roretzi, see Yamada and Nishida, 376–386. Developing mouse cortex consisting with neural progenitor cells positive for Pax6 (magenta) and neurons marked with Tuj1 (green), see Tsunekawa et al., 349–357. Histograms of DNA content per nucleus of mouse cardiomyocytes (mono- and binucleate cells) during postnatal stages, see Takeuchi, 402–409. Middle row from the left: Switching from proliferation (PCNA, magenta) to differentiation (Prox1, green) in the lens, see Mochizuki and Masai, 387–401. Anterior view of the lens of 5 dpf zebrafi sh to show lens fi ber convergence (BODIPY ceramide staining) see Mochizuki and Masai, 387–401, Cell division of Rb-TKO differentiating cortical neurons, see Ajioka, 324–334. Bottom row from the left: Eye imaginal disc stained by anti-Elav (pan-neural marker; green) and Cut (cone cells marker; magenta) see Tsuda and Lim, 358–367. Schematic showing. Cdk5 regulates both presynaptic and postsynaptic proteins and thereby synaptic plasticity, see Kawauchi, 335–348, Developing mouse cerebral cortex. Neural progenitors and multipolar and locomoting neurons, where Cdk5 has various functions, are emphasized, see Kawauchi, 335–347. First published: 25 June 2014 https://doi.org/10.1111/dgd.12083AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume56, Issue5June 2014Pages i-i RelatedInformation

Amyloid precursor protein regulates neurogenesis by antagonizing miR-574-5p in the developing cerebral cortex

Amyloid precursor protein (APP) is a transmembrane glycoprotein proteolytically processed to release amyloid beta, a pathological hallmark of Alzheimer's disease. APP is expressed throughout the developing and mature brain; however, the primary function of this protein is unknown. We previously demonstrated that APP deficiency enhances neurogenesis, but the mechanisms underlying this process are not known. Here we show that APP regulates the expression of microRNAs in the cortex and in neural progenitors, specifically repressing miR-574-5p. We also show that overexpression of miR-574-5p promotes neurogenesis, but reduces the neural progenitor pool. In contrast, the reduced expression of miR-574-5p inhibits neurogenesis and stimulates proliferation in vitro and in utero. We further demonstrate that the inhibition of miR-574-5p in APP-knockout mice rescues the phenotypes associated with APP deficiency in neurogenesis. Taken together, these results reveal a mechanism in which APP regulates the neurogenesis through miRNA-mediated post-transcriptional regulation.

Gene expression and IG-DMR hypomethylation of maternally expressed gene 3 in developing corticospinal neurons

The mammalian cerebral cortex plays a central role in higher cognitive functions and in the complex task of motor control. Maternally expressed gene 3 (Meg3) appears to play a role in cortical development and neurodegeneration, but the expression and regulation of Meg3 in the cortex is not clear. In this study, we examined the expression of transcript variants of Meg3 in the developing mouse cerebral cortex. By in situ hybridization, we found that a novel transcript variant of Meg3 with 8 small exons was expressed in the developing cortex, whereas the long isoforms of Meg3 (∼11kb) were enriched in corticospinal neurons (CSNs) in layer V of the cortex. No transcript variants of Meg3 were found in the neural progenitors at E12.5, when the intergenic differential methylation region (IG-DMR) near Meg3 was highly methylated. IG-DMR became demethylated at E15.5 and remained hypomethylated in early CSNs isolated from Fezf2-EGFP transgenic mice. The expression of Meg3 transcript variant 1 was inversely correlated with the IG-DMR methylation level during development. Moreover, expression of paternally expressed gene Peg11 was limited to the upper layers, consistent with the idea that the maternally expressed gene may be preferentially transcribed in the lower layers of the cortex. The spatiotemporal expression pattern of Meg3 suggests that it may participate in the early development of CSNs and contribute to cortical malfunctions related to aberrant imprinting in Meg3.

The Niche Factor Syndecan-1 Regulates the Maintenance and Proliferation of Neural Progenitor Cells during Mammalian Cortical Development

Neural progenitor cells (NPCs) divide and differentiate in a precisely regulated manner over time to achieve the remarkable expansion and assembly of the layered mammalian cerebral cortex. Both intrinsic signaling pathways and environmental factors control the behavior of NPCs during cortical development. Heparan sulphate proteoglycans (HSPG) are critical environmental regulators that help modulate and integrate environmental cues and downstream intracellular signals. Syndecan-1 (Sdc1), a major transmembrane HSPG, is highly enriched in the early neural germinal zone, but its function in modulating NPC behavior and cortical development has not been explored. In this study we investigate the expression pattern and function of Sdc1 in the developing mouse cerebral cortex. We found that Sdc1 is highly expressed by cortical NPCs. Knockdown of Sdc1 in vivo by in utero electroporation reduces NPC proliferation and causes their premature differentiation, corroborated in isolated cells in vitro. We found that Sdc1 knockdown leads to reduced levels of β-catenin, indicating reduced canonical Wnt signaling. Consistent with this, GSK3β inhibition helps rescue the Sdc1 knockdown phenotype, partially restoring NPC number and proliferation. Moreover, exogenous Wnt protein promotes cortical NPC proliferation, but this is prevented by Sdc1 knockdown. Thus, Sdc1 in the germinal niche is a key HSPG regulating the maintenance and proliferation of NPCs during cortical neurogenesis, in part by modulating the ability of NPCs to respond to Wnt ligands.

Mitotic spindle orientation can direct cell fate and bias Notch activity in chick neural tube.

Inheritance of apical membrane is proposed to maintain vertebrate neural stem cell proliferation. However, evidence for this is contradictory. Using direct clonal analysis and live imaging in chick neural tube, we show that divisions that separate apical and basal components generate an apical daughter, which becomes a neuron, and a basal daughter, which rapidly re-establishes apico-basal polarity and divides again. Using a recently described real-time reporter of Notch activity, we confirm progenitor status and demonstrate that division orientation can influence Notch signalling. In addition, we reveal loss of apical complex proteins on neuronal differentiation onset, suggesting that removal of this inherited complex is part of the neuronal differentiation mechanism. These findings reconcile contradictory data, link asymmetric division to Notch signalling dynamics and identify apical complex loss as a new step towards neuronal differentiation.

Presenilin 2 is involved in apoptosis during development of mouse cerebral cortex

Presenilin 2 is involved in apoptosis during development of mouse cerebral cortex

Effect of Environmental Factor Influencing the Development of Mouse Cerebral Cortex

The cerebral cortex is organized into six cell layers, each of which contains neurons with similar morphology, functions, gene-expression profiles, and projection patterns. These layer-specific neuronal phenotypes are sequentially generated from common cortical progenitor cells in the ventricular zone of dorsal telencephalon. Although recent investigations have clarified important roles of intrinsic factors such as transcription factors and regulators of the cell cycle for the maturation of cortical progenitors, growth factors and neurotrophic factors environmentally supplied by the cerebral cortex are thought to regulate proliferation and neural development and determine neuronal differentiation in the cerebral cortex. In this review, I focus on the function of neurotrophin-family neurotrophic factor, including nerve growth factor, brain-derived neurotrophic factor (BDNF), neurotropin-3 (NT-3) and neurotrophin-4 in the formation of the neuronal layer of the cerebral cortex. Especially, BDNF and NT-3 are expressed in the proliferating cortical progenitors and influence the biological properties of cortical progenitors prior to neurogenesis and play distinct roles in generation of cortical neuronal subtypes.

Gα Subunit Coordinates with Ephrin-B to Balance Self-Renewal and Differentiation in Neural Progenitor Cells

Proper development of the mammalian brain requires that neural progenitor cells balance self-renewal and differentiation under precise temporal and spatial regulation, but the underlying mechanisms are not well understood. In this study, we identify Gα subunit as a positive regulator of mammalian neurogenesis, working with the regulator of G protein signaling (RGS)-mediated ephrin-B signaling pathway as two opposing forces to maintain a balance between self-renewal and differentiation in the developing mouse cerebral cortex. Multiple Gα(i) subunits are expressed by cortical neural progenitor cells during the course of cortical neurogenesis. Activation of Gα(i) signaling, through in utero electroporation-mediated expression of wild-type and constitutively active Gα(i) subunits, counteracts the function of ephrin-B in cortical neural progenitors to induce differentiation. Genetic knock-in of an RGS-insensitive G184SGα(i2) causes early cell cycle exit and a reduction of cortical neural progenitor cells and leads to a defect in the production of late born cortical neurons, similar to what is observed in mutant mice with deficiency in ephrin-B reverse signaling pathway. This study reveals a role of Gα subunit in mammalian neurogenesis and uncovers a developmental mechanism, coordinated by the Gα and ephrin-B signaling pathways, for control of the balance between self-renewal and differentiation in neural progenitor cells.

Bimodal septal and cortical triggering and complex propagation patterns of spontaneous waves of activity in the developing mouse cerebral cortex

Spontaneous waves of activity that propagate across large structures during specific developmental stages play central roles in CNS development. To understand the genesis and functions of these waves, it is critical to understand the spatial and temporal patterns of their propagation. We recently reported that spontaneous waves in the neonatal cerebral cortex originate from a ventrolateral pacemaker region. We have now analyzed a large number of spontaneous waves using calcium imaging over the entire area of coronal slices from E18-P1 mouse brains. In all waves, the first cortical region active is this ventrolateral pacemaker. In half of the waves, however, the cortical pacemaker activity is itself triggered by preceding activity in the septal nuclei. Most waves are restricted to the septum and/or ventral cortex, with only some invading the dorsal cortex or the contralateral hemisphere. Waves fail to propagate at very stereotyped locations at the boundary between ventral and dorsal cortex and at the dorsal midline. Waves that cross these boundaries pause at these same locations. Waves at these stages are blocked by both picrotoxin and CNQX, indicating that both GABA(A) and AMPA receptors are involved in spontaneous activity.

Diversity of Lysophosphatidic Acid Receptor-Mediated Intracellular Calcium Signaling in Early Cortical Neurogenesis

Lysophosphatidic acid (LPA) is a membrane-derived lysophospholipid that can induce pleomorphic effects in neural progenitor cells (NPCs) from the cerebral cortex, including alterations in ionic conductance. LPA-induced, calcium-mediated conductance changes have been reported; however, the underlying molecular mechanisms have not been determined. We show here that activation of specific cognate receptors accounts for nearly all intracellular calcium responses evoked by LPA in acutely cultured nestin-positive NPCs from the developing mouse cerebral cortex. Fast-onset changes in intracellular calcium levels required release from thapsigargin-sensitive stores by a pertussis toxin-insensitive mechanism. The influx of extracellular calcium through Cd(2+)/Ni(2+)-insensitive influx pathways, approximately one-half of which were Gd(3+) sensitive, contributed to the temporal diversity of responses. Quantitative reverse transcription-PCR revealed the presence of all five known LPA receptors in primary NPCs, with prominent expression of LPA(1), LPA(2), and LPA(4). Combined genetic and pharmacological studies indicated that NPC responses were mediated by LPA(1) (approximately 30% of the cells), LPA(2) (approximately 30%), a combination of receptors on single cells (approximately 30%), and non-LPA(1,2,3) pathways (approximately 10%). LPA responsivity was significantly reduced in more differentiated TuJ1(+) cells within cultures. Calcium transients in a large proportion of LPA-responsive NPCs were also initiated by the closely related signaling lipid S1P (sphingosine-1-phosphate). These data demonstrate for the first time the involvement of LPA receptors in mediating surprisingly diverse NPC calcium responses involving multiple receptor subtypes that function within a single cell. Compared with other known factors, lysophospholipids represent the major activator of calcium signaling identified within NPCs at this early stage in corticogenesis.

Gene silencing of NMDA receptor subunit GluN2B disturbs neuronal migration in developing mouse cerebral cortex

Gene silencing of NMDA receptor subunit GluN2B disturbs neuronal migration in developing mouse cerebral cortex

Expression of sex steroid hormone receptors is inversely related to 3β-hydroxysteroid dehydrogenase activity during postnatal development of mouse cerebral cortex

Expression of sex steroid hormone receptors is inversely related to 3β-hydroxysteroid dehydrogenase activity during postnatal development of mouse cerebral cortex

Expression of sex steroid hormone receptors is inversely related to 3β-hydroxysteroid dehydrogenase activity during postnatal development of mouse cerebral cortex

Background: Sex steroids, estrogens and androgens, exert a number of effects on the morphological, biochemical and electrophysiological properties of the brain during its development. These effects are mediated through specific steroid receptors, estrogen receptor α (ERα), estrogen receptor β (ERβ) and androgen receptor (AR). Purpose: The aim of this study was to examine the expression of sex steroid receptors and correlate it to steriodogenesis during postnatal development of the brain. Methods: In the present study, expression of sex steroid hormone receptors and its correlation to 3β-hydroxydehydrogenase (3β-HSD) enzyme activity were examined in the mouse cerebral cortex at postnatal days (PD) 0, 7, 15, 30 and 45. Results: Immunofluorescence results revealed that the expression of both androgen receptor (AR) and estrogen receptors (ERα, ERβ) was lowest at PD0 and highest at PD45 in the cerebral cortex of male and female mice and the increase was evident from PD15. In parallel, the activity of 3-HSD enzyme continually decreased from PD0 to PD45 with no significant difference between male and female. Thus the expression of AR and ER is inversely related to 3-HSD activity in mouse cerebral cortex during postnatal development. Conclusion: These findings suggest the involvement of sex steroid hormone receptors in differentiation and establishment of neural circuitry during postnatal development of the brain. doi : 10.5214/ans.0972.7531.2009.160405 Competing interests: None. Source of Funding: CSIR, DBT, DST Received Date: 27 Aug 2009 Revised Date: 30 Sept 2009 Accepted Date: 12 Oct 2009

Expression of sex steroid hormone receptors is inversely related to 3β-hydroxysteroid dehydrogenase activity during postnatal development of mouse cerebral cortex

Expression of sex steroid hormone receptors is inversely related to 3β-hydroxysteroid dehydrogenase activity during postnatal development of mouse cerebral cortex

The Level of the Transcription Factor Pax6 Is Essential for Controlling the Balance between Neural Stem Cell Self-Renewal and Neurogenesis

Neural stem cell self-renewal, neurogenesis, and cell fate determination are processes that control the generation of specific classes of neurons at the correct place and time. The transcription factor Pax6 is essential for neural stem cell proliferation, multipotency, and neurogenesis in many regions of the central nervous system, including the cerebral cortex. We used Pax6 as an entry point to define the cellular networks controlling neural stem cell self-renewal and neurogenesis in stem cells of the developing mouse cerebral cortex. We identified the genomic binding locations of Pax6 in neocortical stem cells during normal development and ascertained the functional significance of genes that we found to be regulated by Pax6, finding that Pax6 positively and directly regulates cohorts of genes that promote neural stem cell self-renewal, basal progenitor cell genesis, and neurogenesis. Notably, we defined a core network regulating neocortical stem cell decision-making in which Pax6 interacts with three other regulators of neurogenesis, Neurog2, Ascl1, and Hes1. Analyses of the biological function of Pax6 in neural stem cells through phenotypic analyses of Pax6 gain- and loss-of-function mutant cortices demonstrated that the Pax6-regulated networks operating in neural stem cells are highly dosage sensitive. Increasing Pax6 levels drives the system towards neurogenesis and basal progenitor cell genesis by increasing expression of a cohort of basal progenitor cell determinants, including the key transcription factor Eomes/Tbr2, and thus towards neurogenesis at the expense of self-renewal. Removing Pax6 reduces cortical stem cell self-renewal by decreasing expression of key cell cycle regulators, resulting in excess early neurogenesis. We find that the relative levels of Pax6, Hes1, and Neurog2 are key determinants of a dynamic network that controls whether neural stem cells self-renew, generate cortical neurons, or generate basal progenitor cells, a mechanism that has marked parallels with the transcriptional control of embryonic stem cell self-renewal.

Late Origin of Glia-Restricted Progenitors in the Developing Mouse Cerebral Cortex

In order to unravel the molecular determinants of cell fate, it is important to understand when fate restriction occurs during brain development. Lineage analysis suggested that bi- or multipotent progenitors persist into late developmental stages in some central nervous system regions, whereas most progenitor cells in the cerebral cortex appeared to be restrained to generate only a single cell type already at early stages. Here we discuss this previous work and present new data demonstrating that cortical progenitors generating exclusively glial cells appear late in development. In utero transduction of cortical progenitors at early and mid-neurogenesis using a combination of replication-defective retroviral vectors encoding different fluorescent proteins indicated that the early developing cortex is devoid of glia-restricted progenitors, although these are frequent during mid- and late neurogenesis. Clonal analyses in vitro using retroviral vectors and live cell tracking by video time-lapse microscopy confirmed these findings, revealing that the early developing cortex harbors 2 main progenitor types: neuron-restricted and bipotent (neuron-glial) progenitors. The latter are responsible for the generation of glial-restricted progenitors at mid- and late neurogenesis.

Molecular networks involved in mouse cerebral corticogenesis and spatio-temporal regulation of Sox4 and Sox11 novel antisense transcripts revealed by transcriptome profiling.

SAGE analysis reveals spatiotemporally regulated transcripts and overlapping sense and antisense transcripts that are important for mouse cerebral cortex development

Par-complex proteins promote proliferative progenitor divisions in the developing mouse cerebral cortex

The size of brain regions depends on the balance between proliferation and differentiation. During development of the mouse cerebral cortex, ventricular zone (VZ) progenitors, neuroepithelial and radial glial cells, enlarge the progenitor pool by proliferative divisions, while basal progenitors located in the subventricular zone (SVZ) mostly divide in a differentiative mode generating two neurons. These differences correlate to the existence of an apico-basal polarity in VZ, but not SVZ, progenitors. Only VZ progenitors possess an apical membrane domain at which proteins of the Par complex are strongly enriched. We describe a prominent decrease in the amount of Par-complex proteins at the apical surface during cortical development and examine the role of these proteins by gain- and loss-of-function experiments. Par3 (Pard3) loss-of-function led to premature cell cycle exit, reflected in reduced clone size in vitro and the restriction of the progeny to the lower cortical layers in vivo. By contrast, Par3 or Par6 (Pard6alpha) overexpression promoted the generation of Pax6+ self-renewing progenitors in vitro and in vivo and increased the clonal progeny of single progenitors in vitro. Time-lapse video microscopy revealed that a change in the mode of cell division, rather than an alteration of the cell cycle length, causes the Par-complex-mediated increase in progenitors. Taken together, our data demonstrate a key role for the apically located Par-complex proteins in promoting self-renewing progenitor cell divisions at the expense of neurogenic differentiation in the developing cerebral cortex.

Rapid promoter analysis in developing mouse brain and genetic labeling of young neurons by doublecortin‐DsRed‐express

Characterization of neural promoter/enhancers is essential for understanding gene regulation during brain development and provides useful genetic tools. However, it relies on the use of transgenic mice. We report a method for the rapid in vivo analysis of neural promoter/enhancers in the developing mouse brain and its application in the isolation of the doublecortin (DCX) promoter/enhancer for genetic labeling of young neurons. In the present study, we demonstrated that reporter genes introduced into the developing mouse cerebral cortex by in utero electroporation can achieve promoter/enhancer-specific patterns of expression. We used the in utero electroporation system to isolate a genomic fragment of the doublecortin gene that can direct reporter expression faithful to doublecortin in young neurons of the cerebral cortex. Finally, we showed that the DCX promoter identified via electroporation could reproduce doublecortin expression in the entire central nervous system in DCX-DsRed-express transgenic mice. The results of our study provide a convenient, reliable, and rapid method for in vivo analysis of neural promoter/enhancers in the developing mouse brain.

Brain-Derived Neurotrophic Factor Participates in Determination of Neuronal Laminar Fate in the Developing Mouse Cerebral Cortex

Lamina formation in the developing cerebral cortex requires precisely regulated generation and migration of the cortical progenitor cells. To test the possible involvement of brain-derived neurotrophic factor (BDNF) in the formation of the cortical lamina, we investigated the effects of BDNF protein and anti-BDNF antibody separately administered into the telencephalic ventricular space of 13.5-d-old mouse embryos. BDNF altered the position, gene-expression properties, and projections of neurons otherwise destined for layer IV to those of neurons for the deeper layers, V and VI, of the cerebral cortex, whereas anti-BDNF antibody changed some of those of neurons of upper layers II/III. Additional analysis revealed that BDNF altered the laminar fate of neurons only if their parent progenitor cells were exposed to it at approximately S-phase and that it hastened the timing of the withdrawal of their daughter neurons from the ventricular proliferating pool by accelerating the completion of S-phase, downregulation of the Pax6 (paired box gene 6) expression, an essential transcription factor for generation of the upper layer neurons, and interkinetic nuclear migration of cortical progenitors in the ventricular zone. These observations suggest that BDNF participates in the processes forming the neuronal laminas in the developing cerebral cortex. BDNF can therefore be counted as one of the key extrinsic factors that regulate the laminar fate of cortical neurons.