To understand how the nervous system develops from a small pool of progenitors during early embryonic development, it is fundamentally important to identify the diversity of neuronal subtypes, decode the origin of neuronal diversity, and uncover the principles governing neuronal specification across different regions. Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed, leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge. In this review, we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes, including predetermined, stochastic, and cascade diversifying models, and elaborate how these strategies are implemented in distinct regions such as the neocortex, spinal cord, retina, and hypothalamus. Importantly, the identity of neural progenitors is defined by their spatial position and temporal patterning factors, and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes. Microenvironmental cues, spontaneous activity, and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions. The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy, as well as understanding the organization of functional neural circuits and the evolution of the nervous system.
Humans ; Neural Stem Cells/physiology* ; Neurons/physiology* ; Brain ; Spinal Cord ; Embryonic Development ; Cell Differentiation/physiology*

Neurologic deficits resulting from stroke remain largely intractable, which has prompted thousands of studies aimed at developing methods for treating these neurologic sequelae. Endogenous neurogenesis is also known to occur after brain damage, including that due to cerebral infarction. Focusing on this process may provide a solution for treating neurologic deficits caused by cerebral infarction. The phosphatidylinositol-3-kinase (PI3K) pathway is known to play important roles in cell survival, and many studies have focused on use of the PI3K pathway to treat brain injury after stroke. Furthermore, since the PI3K pathway may also play key roles in the physiology of neural stem cells (NSCs), eliciting the appropriate activation of the PI3K pathway in NSCs may help to improve the sequelae of cerebral infarction. This review describes the PI3K pathway, its roles in the brain and NSCs after cerebral infarction, and the therapeutic possibility of activating the pathway to improve neurologic deficits after cerebral infarction.
Brain Injuries ; Brain* ; Cell Survival ; Cerebral Infarction* ; Neural Stem Cells* ; Neurogenesis ; Neurologic Manifestations ; Physiology ; Regeneration* ; Stroke

Several types of molecules, including the small non-coding RNAs, are involved in the precision regulation of neural development. The expression of microRNAs appears in a specific spatialtemporal sequence during the neural development, and abnormal expression may lead to neural dysplasia. MicroRNAs also play important roles in the regulation of cell biological behaviors in terms of survival, proliferation and differentiation. Neural stem cells are the mother cell of the nervous system. The proliferation, differentiation and migration of neural stem cells are tightly controlled so as to generate appropriate number and phenotype of daughter cells to ensure normal neural development. MicroRNAs are involved in the regulation of neural stem cell proliferation and differentiation via affecting the expression and function of their target mRNAs.
Animals ; Cell Differentiation ; Cell Proliferation ; Humans ; MicroRNAs ; physiology ; Nervous System ; growth & development ; Neural Stem Cells ; cytology ; physiology

OBJECTIVETo observe the effect of non-contact coculture on bone marrow stromal cells (MSCs) and neural stem cells (NSCs) in neural stem cell culture medium.

METHODSMSCs and NSCs were cultured in non-contact coculture in Transwell plate, and cell morphology and immunocytochemical profile were investigated.

RESULTSIn the coculture, the NSCs showed adhering growth and extended long processes, and the migrating cells formed a network of cells within 7 days. The cells differentiated into neurons, astrocytes and oligodendrocytes as shown by immunocytochemistry. Most of the MSCs grew in a non-adherent manner, giving rise to large spherical cell masses which expressed neuronal, astrocyte, and oligodendrocyte phenotypes. In the control group, the NSCs grew in suspension, some of MSCs formed small non-adherent spherical cell masses, while some cells showed adherent growth.

CONCLUSIONMSCs and NSCs in the non-contact coculture can mutually promote the cell differentiation into neural cells in neural stem cell culture medium, indicating that both MSCs and NSCs can secrete some neurotrophic factors to provide a microenvironment suitable for survival and differentiation for each other.

Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Cells, Cultured ; Coculture Techniques ; methods ; Female ; Male ; Neural Stem Cells ; cytology ; Rats ; Rats, Wistar ; Stromal Cells ; cytology ; metabolism ; physiology

Living organisms are exposed to the geomagnetic field (GMF) throughout their lifespan. Elimination of the GMF, resulting in a hypogeomagnetic field (HMF), leads to central nervous system dysfunction and abnormal development in animals. However, the cellular mechanisms underlying these effects have not been identified so far. Here, we show that exposure to an HMF (<200 nT), produced by a magnetic field shielding chamber, promotes the proliferation of neural progenitor/stem cells (NPCs/NSCs) from C57BL/6 mice. Following seven-day HMF-exposure, the primary neurospheres (NSs) were significantly larger in size, and twice more NPCs/NSCs were harvested from neonatal NSs, when compared to the GMF controls. The self-renewal capacity and multipotency of the NSs were maintained, as HMF-exposed NSs were positive for NSC markers (Nestin and Sox2), and could differentiate into neurons and astrocyte/glial cells and be passaged continuously. In addition, adult mice exposed to the HMF for one month were observed to have a greater number of proliferative cells in the subventricular zone. These findings indicate that continuous HMF-exposure increases the proliferation of NPCs/NSCs, in vitro and in vivo. HMF-disturbed NPCs/NSCs production probably affects brain development and function, which provides a novel clue for elucidating the cellular mechanisms of the bio-HMF response.
Animals ; Cell Proliferation ; physiology ; Female ; Magnetic Fields ; Male ; Mice ; Nestin ; metabolism ; Neural Stem Cells ; cytology ; metabolism ; SOXB1 Transcription Factors ; metabolism

Chronic stress impairs radial neural stem cell (rNSC) differentiation and adult hippocampal neurogenesis (AHN), whereas promoting AHN can increase stress resilience against depression. Therefore, investigating the mechanism of neural differentiation and AHN is of great importance for developing antidepressant drugs. The nonpsychoactive phytocannabinoid cannabidiol (CBD) has been shown to be effective against depression. However, whether CBD can modulate rNSC differentiation and hippocampal neurogenesis is unknown. Here, by using the chronic restraint stress (CRS) mouse model, we showed that hippocampal rNSCs mostly differentiated into astrocytes under stress conditions. Moreover, transcriptome analysis revealed that the FoxO signaling pathway was involved in the regulation of this process. The administration of CBD rescued depressive-like symptoms in CRS mice and prevented rNSCs overactivation and differentiation into astrocyte, which was partly mediated by the modulation of the FoxO signaling pathway. These results revealed a previously unknown neural mechanism for neural differentiation and AHN in depression and provided mechanistic insights into the antidepressive effects of CBD.
Animals ; Cannabidiol/pharmacology* ; Cell Differentiation ; Depression/prevention & control* ; Hippocampus/metabolism* ; Humans ; Mice ; Neural Stem Cells ; Neurogenesis/physiology*

OBJECTIVETo investigate the effect of telomerase activation on biological behaviors of neural stem cells after hypoxic-ischemic insults.

METHODSThe neural stem cells passaged in vitro were divided into four groups: control, oxygen-glucose deprivation (OGD), OGD+cycloastragenol (CAG) high concentration (final concentration of 25 μM), and OGD+CAG low concentration (final concentration of 10 μM). The latter three groups were subjected to OGD. Telomerase reverse transcriptase (TERT) expression level was evaluated by Western blot. Telomerase activity was detected by telomerase repeat amplification protocol (TRAP). Cell number and neural sphere diameter were measured under a microscope. The activity of lactate dehydrogenase (LDH) was examined by chemiluminescence. Cell proliferation rate and apoptosis were detected by flow cytometry.

RESULTSAfter OGD insults, obvious injury of neural stem cells was observed, including less cell number, smaller neural sphere, more dead cells, lower proliferation rate and decreased survival rate. In CAG-treated groups, there were higher TERT expression level and telomerase activity compared with the control group (P<0.05). In comparison with the OGD group, CAG treatment attenuated cell loss (P<0.05) and neural sphere diameter decrease (P<0.05), promoted cell proliferation (P<0.05), and increased cell survival rate (P<0.05). Low and high concentrations of CAG had similar effects on proliferation and survival of neural stem cells (P>0.05). In the normal cultural condition, CAG treatment also enhanced TERT expression (P<0.05) and increased cell numbers (P<0.05) and neural sphere diameter (P<0.05) compared with the control group.

CONCLUSIONSTelomerase activation can promote the proliferation and improve survival of neural stem cells under the state of hypoxic-ischemic insults, suggesting telomerase activators might be potential agents for the therapy of hypoxic-ischemic brain injury.

Animals ; Cell Survival ; drug effects ; Enzyme Activation ; Hypoxia-Ischemia, Brain ; etiology ; Neural Stem Cells ; drug effects ; physiology ; Rats ; Sapogenins ; pharmacology ; Telomerase ; physiology

AIMTo observe the change of potassium current on cultured neurons differentiated from hippocampus neural stem cells of the newborn rat.

METHODSNeural stem cells from newborn rat hippocampus were cultured in vitro and passaged continuously. Differentiation of the cell was induced by serum and removing mitogens. After differentiation cells were plated on plastic dishes and cultured for 1 d, 7 d, 14 d and 21 d. Whole-cell voltage patch clamp recording was used respectively to detect voltage-dependent K+ current.

RESULTSAfter 1 d culture, no current was detected, and on the 7th d, 14th d, 21st d after differentiation, the amplitude of K+ currents was (18.077 +/- 2.789)pA/pF, (13.099 +/- 2.742)pA/pF, (34.045 +/- 8.067)pA/pF at +50 mV. The recorded K+ current included two components that could be blocked by TEA and 4-AP separately, assumed the slowly inactivating delayed rectifier K+ current (IK) and the fast inactivating transient outward K+ current (IA).

CONCLUSIONThe function of potassium channels on the hippocampus neural stem cells of the newborn rat approaches mature gradually when the time of differentiation becomes longer in vitro.

Animals ; Animals, Newborn ; Cells, Cultured ; Delayed Rectifier Potassium Channels ; physiology ; Hippocampus ; cytology ; Neural Stem Cells ; cytology ; metabolism ; physiology ; Patch-Clamp Techniques ; Potassium Channels ; physiology ; Potassium Channels, Inwardly Rectifying ; physiology ; Rats ; Rats, Sprague-Dawley

To study the attachment, proliferation and differentiation of neural stem cells (NSCs) on surface modified PHBHHx films and to establish the theory of PHBHHx application in NSCs-based brain tissue engineering. PHBHHx film was fabricated by a solution-casting method, and the morphology of the film was observed under scanning electron microscopy(SEM). The films were treated by NaOH or lipase, then the surface hydrophilic property was characterized using water contact angle measurement. NSCs were isolated from the cerebral cortex of rat embryos on embryonic day 14.5, and cultured on surface treated PHBHHx films. The morphology of NSCs attached on the film was visualized under SEM, and the survival and differentiation of NSCs were observed through immunocytochemical staining. Compared with the untreated PHBHHx films, the water contact angle of NaOH or lipase treated PHBHHx films decreased dramatically, and the number of NSCs attached significantly increased. NSCs survived well on treated PHBHHx films and differentiated into neurons and glial cells. The amelioration of hydrophilic property of PHBHHx film improved its biocompatibility with NSCs. PHBHHx can serve as a novel CNS tissue engineering biomaterial applied for NSCs transplantation, brain repairing and regeneration.
3-Hydroxybutyric Acid ; chemistry ; Animals ; Caproates ; chemistry ; Cell Adhesion ; physiology ; Cell Differentiation ; drug effects ; Cell Proliferation ; Cells, Cultured ; Cerebral Cortex ; cytology ; Coated Materials, Biocompatible ; chemistry ; Embryonic Stem Cells ; cytology ; Female ; Neural Stem Cells ; cytology ; Rats ; Surface Properties ; Tissue Engineering

Inducible cyclooxygenase-2 (COX-2) has received much attention because of its role in neuro-inflammation and synaptic plasticity. Even though COX-2 levels are high in healthy animals, the function of this factor in adult neurogenesis has not been clearly demonstrated. Therefore, we performed the present study to compare the effects of pharmacological and genetic inhibition of COX-2 on adult hippocampal neurogenesis. Physiological saline or the same volume containing celecoxib was administered perorally every day for 5 weeks using a feeding needle. Compared to the control, pharmacological and genetic inhibition of COX-2 reduced the appearance of nestin-immunoreactive neural stem cells, Ki67-positive nuclei, and doublecortin-immunoreactive neuroblasts in the dentate gyrus. In addition, a decrease in phosphorylated cAMP response element binding protein (pCREB) at Ser133 was observed. Compared to pharmacological inhibition, genetic inhibition of COX-2 resulted in significant reduction of neural stem cells, cell proliferation, and neuroblast differentiation as well as pCREB levels. These results suggest that COX-2 is part of the molecular machinery that regulates neural stem cells, cell proliferation, and neuroblast differentiation during adult hippocampal neurogenesis via pCREB. Additionally, genetic inhibition of COX-2 strongly reduced neural stem cell populations, cell proliferation, and neuroblast differentiation in the dentate gyrus compared to pharmacological inhibition.
Animals ; Celecoxib/*pharmacology ; Cell Differentiation/drug effects/physiology ; Cell Proliferation/drug effects/physiology ; Cyclooxygenase 2/*genetics/metabolism ; Cyclooxygenase 2 Inhibitors/*pharmacology ; Dentate Gyrus/drug effects/*physiology ; Male ; Mice ; Mice, Knockout ; Neural Stem Cells/drug effects/physiology ; Neurogenesis/drug effects