ライフサイエンスコーパス: neural stem cell

1 iate neural progenitors (INPs) from a single neural stem cell.

2 conditional targeting of CSP-alpha in adult neural stem cells.

3 of the proliferation and differentiation of neural stem cells.

4 neurons and also in radial glia, behaving as neural stem cells.

5 increases proliferation and self-renewal of neural stem cells.

6 d genes ZIC2, GLI2, SMAD3 and FGFR1 in human neural stem cells.

7 tivity in Drosophila asymmetrically dividing neural stem cells.

8 diverse cell types, and affected survival in neural stem cells.

9 th the quiescent and proliferative states of neural stem cells.

10 nesis failure, including polyploidization of neural stem cells.

11 ls, indicating fusion between the cancer and neural stem cells.

12 cells) that have many properties similar to neural stem cells.

13 ed transcriptional prepatterning in cortical neural stem cells.

14 c protein distribution in mitotic Drosophila neural stem cells.

15 al cortex growth and midbody organization of neural stem cells.

16 tors to stimulate nerve regrowth, or recruit neural stem cells.

17 ed growth factor to sustain proliferation of neural stem cells.

18 ted the Zika virus protease and infection in neural stem cells.

19 pecificity, generated by a limited number of neural stem cells.

20 levate the proliferation and survival of the neural stem cells.

21 to inhibit Akt-mTOR signaling in human fetal neural stem cells, a key pathway for brain development.

22 to support the growth and differentiation of neural stem cells- a major transplant population being t

23 ce of defined microdomains of pre-determined neural stem cells along the ventricle walls.

24 In the postnatal forebrain regionalized neural stem cells along the ventricular walls produce ol

25 rmination of the proliferation of Drosophila neural stem cells, also known as neuroblasts (NBs), requ

26 encing analyzing 28,726 cells, we identified neural stem cell and neural progenitor cell pools and ne

27 lso show that ET-1 is required for increased neural stem cell and OPC proliferation in the adult mous

28 include proliferation and differentiation of neural stem cells and extensive rewiring of the remainin

29 r mechanism of retinoid receptor proteins in neural stem cells and glioma stem-like cells.

30 n NRF2-dependent transcriptional response in neural stem cells and identified SPP1 up-regulation as a

31 MYT1L, as indicated by our analyses in human neural stem cells and in the human brain.

32 CHD7 has been described to be essential for neural stem cells and it is also highly expressed or mut

33 of AMPK signaling and protein translation in neural stem cells and its association with Drosophila me

34 e transcription factor signatures of defined neural stem cells and neuron populations.

35 Here we show that FTO is expressed in adult neural stem cells and neurons and displays dynamic expre

36 ed with putative cells of origin for glioma, neural stem cells and oligodendrocyte precursor cells, e

37 ain contains neurogenic niches that comprise neural stem cells and other cell types.

38 e much less effect on the growth of wildtype neural stem cells and Prospero neural tumours.

39 ND surfaces, whereas the viability of mouse neural stem cells and rat neuroblastic cells was improve

40 ce of bidirectional growth signaling between neural stem cells and surrounding cell types in the brai

41 clude that parenchymal astrocytes are latent neural stem cells and that targeted interventions can gu

42 tool for assessing in vivo functionality of neural stem cells and their suitability for neural repai

43 the mother centriole in specific subtypes of neural stem cells, and in almost all basal progenitors.

44 to investigate how FXR1P deficiency in adult neural stem cells (aNSCs) affects proliferation and neur

45 SIGNIFICANCE STATEMENT: Adult neural stem cells (aNSCs) in the hippocampus self-renew

46 elevated during the differentiation of adult neural stem cells (aNSCs), and Tet2 is primarily respons

47 Most adult neural stem cells are maintained in a state of reversibl

48 Adult neural stem cells are mostly quiescent and only rarely e

49 isms underlying positional identity of these neural stem cells are poorly understood.

50 istinctive proliferation rates of individual neural stem cells are unknown.

51 Multiple CH genes are key regulators of neural stem cell biology and converge in human transcrip

52 ular dystrophies, hematopoiesis, cancer, and neural stem cell biology, highlighting the importance of

53 Administration of human neural stem cells by intracerebral implantation is feasi

54 enhancer is maintained in a poised state in neural stem cells by the histone deacetylase Hdac1/Rpd3.

55 larval development, asymmetrically-dividing neural stem cells, called neuroblasts, progress through

56 w that in asymmetrically dividing Drosophila neural stem cells, cell intrinsic polarity cues provide

57 In the developing mammalian neocortex, neural stem cells change competence over time to sequent

58 anscriptomes reveals a decrease in activated neural stem cells, changes in endothelial cells and micr

59 Neural stem cells continuously generate newborn neurons

60 ation of histone epigenetic modifications in neural stem cells cultured on microstructured substrates

61 Human neural stem cell cultures provide progenitor cells that

62 d in HSV-1-infected 2D neuronal cultures and neural stem cell cultures, as well as in HSV-1-infected

63 gnaling due to trisomy 21, thereby promoting neural stem cell cycling that delays terminal differenti

64 In vitro cultured neural stem cells derived from Cic conditional knockout

65 This enabled us to discover that neural stem cells, derived from the murine spinal cord a

66 erneurons induced AHN deficits but increased neural stem cell-derived astrogliosis, associating with

67 study developed novel methods to co-culture neural stem cell-derived spiral ganglion-like neurons (S

68 creates an epigenetic program that triggers neural stem cell differentiation during cortical develop

69 proteins were expressed during all stages of neural stem cell differentiation in the dentate gyrus, w

70 The insights from hematopoietic and neural stem cell differentiation pathways were used to i

71 Ablation of the microRNA-17-92 cluster in neural stem cells diminishes adult hippocampal neurogene

72 Neural stem cells directly or indirectly generate all ne

73 Epithelial-like neural stem cells divide in the ventricular zone at the

74 hway impinging on asymmetric determinants of neural stem cell division.

75 what extent can dentate gyrus (DG)-resident neural stem cells drive regeneration of an injured DG ha

76 Like mammalian neural stem cells, Drosophila type II neuroblasts utiliz

77 or neurodegenerative disorders and preserve neural stem cells during cytostatic cancer therapies.

78 ll replacement of lost neurons using enteric neural stem cells (ENSC) is a possible therapy for these

79 2 appear to be responsible for the increased neural stem cell exit from the VZ and cortical migration

80 trosomes and the SAC, brain cells, including neural stem cells, experience massive errors in mitosis,

81 hat mouse hippocampal radial glia-like (RGL) neural stem cells express the synaptic cochaperone cyste

82 Cell, Kalamakis et al. (2019) show that aged neural stem cells face greater barriers to exiting quies

83 hanistic understanding of how MCPH1 controls neural stem cell fate and brain development.

84 s epigenetic regulation at key regulators of neural stem cell fate ensuring adequate NSPCs self-renew

85 dentified specific compounds that can direct neural stem cell fate toward a specific lineage in vivo,

86 n effective chemical approach for generating neural stem cells from mouse fibroblasts and reveals mec

87 In addition, neural stem cells from Upf3b-null mice have impaired abi

88 ial novel mechanism linking Pb exposure with neural stem cell function and neurodevelopment in childr

89 gulating expression of factors implicated in neural stem cell function.

90 icular-subventricular zone (V-SVZ), in which neural stem cells generate olfactory bulb-destined inter

91 How neural stem cells generate the correct number and type o

92 ity to reconnect the severed spinal cord via neural stem cell grafts, and modulation of neuronal acti

93 Transplantation of human neural stem cells has long been proposed as a potential

94 promotes both of these programs within adult neural stem cells has remained unclear.

95 Neural stem cells have been envisioned as a source of do

96 ing brain development, the daughter cells of neural stem cells have to make a choice - either to beco

97 delayed transplantation of human CNS-derived neural stem cells (hCNS-SCns) at 9 or 30 d post-SCI (dpi

98 functional differentiation of human induced neural stem cells (hiNSCs) into healthy neurons and astr

99 Hence we developed human neural stem cell (hNSC) 3-dimensional (3D) cultures and

100 success treating RICD in rodents using human neural stem cell (hNSC) transplantation, but the procedu

101 the AR to influence gene expression in human neural stem cells (hNSC)-particularly for genes of high-

102 manufacturing practice protocol-grade human neural stem cells (hNSC).

103 e immunity alter fate and migration of human neural stem cells (hNSC).

104 q modulating the migration and fate of human neural stem cells (hNSC); however, the mechanism underly

105 raction of nanodiamond monolayers with human Neural Stem Cells (hNSCs) has been investigated.

106 nd a product of dys-biotic ASD gut, on human neural stem cells (hNSCs) proliferation, differentiation

107 Printed human neural stem cells (hNSCs) show high viability, neural di

108 e sensing, contributing to the regulation of neural stem cell homeostasis.

109 ly linked to master regulators essential for neural stem cell identify.

110 pus of a mouse model of Alzheimer's disease, neural stem cells illuminated following a polarity-optim

111 Human neural stem cell implantation may offer improved recover

112 hat T cells can inhibit the proliferation of neural stem cells in co-cultures and in vivo, in part by

113 y reveals an interaction between T cells and neural stem cells in old brains, opening potential avenu

114 similarities between enteric glia and brain neural stem cells in teleosts and open new possibilities

115 Neural stem cells in the adult mammalian brain are the s

116 Ever since the discovery of neural stem cells in the mammalian brain, the possibilit

117 Striatal astrocytes were located upstream of neural stem cells in the neuronal lineage.

118 eurogenic radial glia-like cells (resembling neural stem cells in the SVZ), (2) neuronal cells, and (

119 tyrate (PBA), reduces protein aggregation in neural stem cells in vitro and in embryos in vivo.

120 In neural stem cells in vitro, high glucose elevates O-GlcN

121 ration and neuronal differentiation of adult neural stem cells in vivo, which leads to impaired learn

122 ents' induced pluripotent stem cells-derived neural stem cells incubated with ibuprofen showed increa

123 tal ZIKV infection that are not explained by neural stem cell infection alone, such as calcifications

124 we provide evidence that TD-derived induced neural stem cells (iNSCs) are an efficacious therapeutic

125 Induced pluripotent stem cell-derived neural stem cells (iNSCs) have significant potential as

126 Here, we show that the differentiation of neural stem cells into neurons can be accelerated by cir

127 y of 50 Hz stimulates the differentiation of neural stem cells into the neuronal phenotype.

128 sophila larval optic lobe, the generation of neural stem cells involves an epithelial-to-mesenchymal-

129 ically altering cell cycle dynamics in adult neural stem cells leads to an increase in new-born neuro

130 erebral implantation of the allogeneic human neural stem cell line CTX0E03 in the subacute-chronic re

131 approach: using pharmacogenomics to focus on neural stem cell lineage, they identified specific compo

132 infection in human cervical, placental, and neural stem cell lines, as well as primary human amnion

133 lfactory bulb, are continuously generated by neural stem cells located in the ventricular and subvent

134 s and oligodendrocytes can be generated from neural stem cells located within the Sub-Ventricular Zon

135 Adult neural stem cells, located in discrete brain regions, ge

136 udies show that Prdm16 is required for adult neural stem cell maintenance and neurogenesis as well as

137 e we demonstrate that Prdm16 is required for neural stem cell maintenance and neurogenesis in the adu

138 uggesting that IE2 concurrently dysregulates neural stem cell maintenance in the VZ and neuronal migr

139 nigral afferents in the regulation of adult neural stem cell maintenance, identifying the first syna

140 rosphere formation and for the expression of neural stem cell markers and Notch target genes in prima

141 This study demonstrates that neural stem cells may offer significant therapeutic bene

142 us (DG) is a unique brain region maintaining neural stem cells (NCSs) and neurogenesis into adulthood

143 on, genes regulating growth and migration of neural stem cells need to be well characterized.

144 at the size and division rates of Drosophila neural stem cells (neuroblasts) are controlled by the hi

145 ral factors activate the death of Drosophila neural stem cells (neuroblasts) by controlling the trans

146 During Drosophila embryonic development, neural stem cells (neuroblasts) sequentially express tra

147 D-SIM) and live-cell imaging, we show in fly neural stem cells (neuroblasts) that the mitotic kinase

148 e asked whether nutrient-dependent growth of neural stem cells (neuroblasts), glia, and trachea is co

149 (INPs) generated by asymmetrically dividing neural stem cells (neuroblasts).

150 erality within a subpopulation of Drosophila neural stem cells (neuroblasts).

151 , Liu et al. (2017) demonstrate that in some neural stem cells, Notch activity is asymmetrically ampl

152 nd surface topography, enable the control of neural stem cell (NSC) differentiation and neurite outgr

153 brin-Matrigel mixed gel was found to promote neural stem cell (NSC) differentiation into neurons and

154 HA contributes to age-related reductions in neural stem cell (NSC) expansion and differentiation in

155 Trim71 as a critical regulator of mammalian neural stem cell (NSC) fate and a bona fide human diseas

156 microRNAs (miRNAs) regulate neural stem cell (NSC) function.

157 butions of niche cell types to regulation of neural stem cell (NSC) homeostasis and maturation of adu

158 1 is particularly abundant in the early-born neural stem cell (NSC) lineage and regulates neuronal mo

159 In Drosophila neural stem cell (NSC) lineages, excessive Notch signall

160 Mammalian neural stem cell (NSC) lines provide a tractable model f

161 he SOX2 transcription factor is critical for neural stem cell (NSC) maintenance and brain development

162 subventricular zone play a critical role in neural stem cell (NSC) maintenance, quiescence and survi

163 Regulation of adult neural stem cell (NSC) number is critical for lifelong n

164 entially required for the maintenance of the neural stem cell (NSC) pool in the adult subventricular

165 size involves balancing rates and timing of neural stem cell (NSC) proliferation, neurogenesis and c

166 e progression, and is required for embryonic neural stem cell (NSC) proliferation.

167 n shown that vascular niche signals regulate neural stem cell (NSC) quiescence and growth.

168 Increased neural stem cell (NSC) quiescence is a major determinant

169 search has revealed an unexpected ability of neural stem cell (NSC) therapies to provide neurotrophic

170 explore the idea, described in terms of the neural stem cell (NSC)/carnitine malnutrition hypothesis

171 This study is aimed to evaluate UPE from neural stem cells (NSC) during their serial passaging an

172 characterized a genetic mouse model in which neural stem cells (NSC) of the subventricular zone (SVZ)

173 two different cells of origin reminiscent of neural stem cells (NSC) or oligodendrocyte precursor cel

174 Transplanted human neural stem cells (NSC) that have the potential to diffe

175 ogenesis, the generation of new neurons from neural stem cells (NSC), in offspring.

176 herapeutic efficiency of allogenic/intrinsic neural stem cells (NSCs) after spinal cord injury is sev

177 Here we mapped the ZIKV-host interactome in neural stem cells (NSCs) and found that Dicer is specifi

178 uring neuronal differentiation are silent in neural stem cells (NSCs) and occupy black chromatin and

179 teral SVZ in early postnatal mice, including neural stem cells (NSCs) and their immediate progenies,

180 increasing evidence demonstrating that adult neural stem cells (NSCs) are a cell of origin of gliobla

181 Neural stem cells (NSCs) are a heterogeneous population

182 Adult neural stem cells (NSCs) are defined by their inherent c

183 Neural stem cells (NSCs) are multipotent progenitors tha

184 ates promote the neuronal differentiation of neural stem cells (NSCs) by suppressing cytoskeletal con

185 diseases including multiple sclerosis (MS), neural stem cells (NSCs) can replace damaged oligodendro

186 The mammalian brain contains few niches for neural stem cells (NSCs) capable of generating new neuro

187 Adult hippocampal dentate gyrus (DG) neural stem cells (NSCs) continuously undergo proliferat

188 Neural stem cells (NSCs) differentiate into both neurons

189 dies that address a central question: How do neural stem cells (NSCs) divide in different ways to pro

190 is review discusses mechanisms that regulate neural stem cells (NSCs) during aging, focusing on the e

191 nt neurogenic activity of individual pallial neural stem cells (NSCs) from embryo to adult.

192 s study, we have developed highly expandable neural stem cells (NSCs) from HESCs and iPSCs that artif

193 device for biomanufacturing patient specific neural stem cells (NSCs) from iPSCs.

194 Neural stem cells (NSCs) generate neurons and glial cell

195 Neural stem cells (NSCs) generate neurons throughout lif

196 es the production of projection neurons from neural stem cells (NSCs) in a cell-autonomous manner, al

197 Neural stem cells (NSCs) in specialized niches in the ad

198 Quiescent neural stem cells (NSCs) in the adult brain are regenera

199 Here, we show that neural stem cells (NSCs) in the adult mouse hippocampus

200 al for the normal cycling and maintenance of neural stem cells (NSCs) in the brain subependymal zone

201 Neural stem cells (NSCs) in the dentate gyrus (DG) resid

202 Neural stem cells (NSCs) in the developing and postnatal

203 m1) and Pum2, severely reduced the number of neural stem cells (NSCs) in the postnatal dentate gyrus

204 Adult neural stem cells (NSCs) in the ventricular-subventricul

205 a receptor-independent manner, especially in neural stem cells (NSCs) in which the expression of opio

206 Hippocampal neural stem cells (NSCs) integrate inputs from multiple

207 evels modulate the differentiation of murine neural stem cells (NSCs) into neurons and astroglial-lik

208 concerted production of neurons and glia by neural stem cells (NSCs) is essential for neural circuit

209 The quiescence of adult neural stem cells (NSCs) is regulated by local parvalbum

210 natal co-deletion of Pten and Trp53 in mouse neural stem cells (NSCs) leads to the expansion of these

211 BVs) are considered an integral component of neural stem cells (NSCs) niches.

212 Here, we report a dramatic drop in the neural stem cells (NSCs) number in the aging murine brai

213 We found that inhibition of OxPhos in neural stem cells (NSCs) or tumours in the Drosophila br

214 In the adult rodent brain, neural stem cells (NSCs) persist in the ventricular-subv

215 Neural stem cells (NSCs) play an essential role in shapi

216 art's neurogenic potential, radial glia-like neural stem cells (NSCs) proliferation and differentiati

217 ating specificity of Zika virus infection in neural stem cells (NSCs) remains elusive.

218 Neural stem cells (NSCs) reside in a unique microenviron

219 Adult neural stem cells (NSCs) reside in specialized niches, w

220 in of the proper size and structure requires neural stem cells (NSCs) to divide with tight temporal a

221 stem cells (GSCs), 50 primary tumors, and 10 neural stem cells (NSCs) to identify essential super-enh

222 The ability of neural stem cells (NSCs) to transit between quiescence a

223 During development, neural stem cells (NSCs) undergo transitions from neuroe

224 Here we demonstrate that adult neural stem cells (NSCs) utilize aggresomes to recover f

225 Neural stem cells (NSCs) within the hippocampal niche in

226 ked back to a pathologically primed stage in neural stem cells (NSCs), reflected by altered chromatin

227 which was due to inhibited proliferation of neural stem cells (NSCs).

228 development, driven by the cell divisions of neural stem cells (NSCs).

229 generate neuronal and glial cell types from neural stem cells (NSCs).

230 ophila optic lobe neuroepithelium to produce neural stem cells (NSCs).

231 damage responses between neonatal and adult neural stem cells (NSCs).

232 ration of hippocampal neurons from quiescent neural stem cells (NSCs).

233 or the limited repair capacity of endogenous neural stem cells (NSCs).

234 ressant, on the proliferation of hippocampal neural stem cells (NSCs).

235 e dynamic responses of differentiating adult neural stem cells (NSCs).

236 trauma stimulate proliferation of endogenous neural stem cells (NSCs); however, the survival of young

237 ctions in inflammation/gliosis and increased neural stem cell numbers in areas of tissue injury.

238 e first report of adipor expression in adult neural stem cells of fish, suggesting a potential role o

239 dent long-chain fatty acid beta-oxidation in neural stem cells of the developing mammalian brain.

240 mainly cells with characteristics of either neural stem cells or cardiomyocytes.

241 Neural stem cells or neuroblasts in the Drosophila melan

242 pendyma are not a major source of endogenous neural stem cells or neuroprotective astrocytes after SC

243 dly detectable in non-neoplastic astrocytes, neural stem cells or normal brain.

244 ng the Trp53 tumor suppressor gene in murine neural stem cells or progenitors.

245 or cells, thereby exhausting the hippocampal neural stem cell pool.

246 hysiological stimuli are relayed to resident neural stem cell populations to control the transcriptio

247 osure to methylmercury was shown to decrease neural stem cell populations, whereas aerobic fitness ha

248 Quiescent neural stem cells present a low rate of metabolic activi

249 radial glial (oRG) cells are a population of neural stem cells prevalent in the developing human cort

250 Adult neural stem cells/progenitor cells residing in the basal

251 ron-enriched embryonic raphe nucleus-derived neural stem cells/progenitors (RN-NSCs) into a complete

252 Consequently, grafted raphe nucleus-derived neural stem cells/progenitors acted as a neuronal relay

253 ron enriched embryonic raphe nucleus-derived neural stem cells/progenitors into the lesion site of co

254 In contrast, early cortical neural stem cells proliferate and expand normally in the

255 olecular mechanisms that regulate or perturb neural stem cell proliferation and differentiation, howe

256 of myc mRNA stability fine-tunes individual neural stem cell proliferation rates.

257 lammatory program induced by METH regulating neural stem cell proliferation, differentiation, and cel

258 adult mice brains, all compounds stimulated neural stem cell proliferation, migration, and different

259 ey microtubule-mediated processes, including neural stem cell proliferation, radial migration, and gr

260 Here, we show that in normal neural stem cells, proteasomal degradation of retinoid r

261 Hence, the patient-derived iPSCs and neural stem cells provide a system to further unravel th

262 in this review our current understanding of neural stem cell quiescence and its regulation by intrin

263 The molecular basis for the neural stem cell quiescence-to-activation transition has

264 Brain neural stem cells (radial glial progenitors, RGPs) under

265 om tightly controlled growth and division of neural stem cells, regulated systemically by important k

266 naling pathway, playing an important role in neural stem cell regulation during mammalian brain devel

267 key neurodevelopmental processes, including neural stem cell regulation, proper positioning of migra

268 Interestingly, high levels of the neural stem cell regulator TLX correlate with poor patie

269 a new human neuronal cell model of HD, using neural stem cells (ReNcell VM NSCs) stably transduced to

270 s disease (AD) exhibiting reduced ability of neural stem cell renewal, we hypothesized that de novo m

271 MBD1 is expressed in neural stem cells residing in the dentate gyrus of the a

272 We previously showed that MCPH1 deletion in neural stem cells results in early mitotic entry that di

273 Radial glia-like neural stem cells (RGLs) in the dentate gyrus subregion

274 The prevalence of neural stem cell scaffolds and their expression of RND3

275 Here we encapsulate homotypic spinal cord neural stem cells (scNSCs) in an alginate-based neural r

276 ible mice and showed that H3.3 K27M enhanced neural stem cell self-renewal while preserving regional

277 We report here that mice with embryonic neural stem-cell-specific deletion of Llgl1 (Nestin-Cre/

278 kers for GSC are developed from embryonic or neural stem cell systems; however, currently available G

279 Here we unravel a mechanism decoding neural stem cell temporal gene expression and transformi

280 Here, subventricular zone neural stem cells that generate olfactory bulb granule c

281 express interferon-gamma, and the subset of neural stem cells that has a high interferon response sh

282 Ependyma have been proposed as adult neural stem cells that provide the majority of newly pro

283 ScNs were obtained from neural stem cells that were derived from transgenic mous

284 also provide evidence that, similar to brain neural stem cells, the activation and neuronal different

285 persistence of radial glial cells acting as neural stem cells, the brain of the adult zebrafish cons

286 These data demonstrate the potential of neural stem cell therapies to restore normal myelination

287 es and can potentially have a high impact on neural stem cell therapy.

288 Here we use Drosophila neural stem cells to elucidate the mechanisms involved i

289 a deficiency in differentiation of trisomic neural stem cells to neurons, correctible by inducing XI

290 NF-kappaB-mediated signaling that activates neural stem cells to reconstitute the olfactory epitheli

291 we then tested the capacity of transplanted neural stem cells to restore myelin in the context of PL

292 Furthermore, Cic loss biases neural stem cells toward glial lineage selection, expand

293 and colleagues asked whether the results of neural stem cell transplantation might be improved by ac

294 One example is the neural stem cell tumours that arise from constitutive No

295 to a reduced number of both radial glia-like neural stem cells (type-1 cells) and intermediate progen

296 lar mechanisms by which REST regulates adult neural stem cells, we perform chromatin immunoprecipitat

297 a muted NRF2 activation response in human HD neural stem cells, which was restored by genetic correct

298 Here we show that neural stem cells, with absent or reduced DCX protein ex

299 tency of human pluripotent stem cell-derived neural stem cells within 5 days and to convert these cel

300 -activating protein, in the radial glia-like neural stem cells within the ventricular zone of the med