Vascular endothelial growth factor (VEGF) was originally recognized as a substance predominantly with vascular permeability and angiogenesis. Recently, more and more evidence indicated that VEGF is expressed in the neurons of the developing and adult brains. Functional investigation demonstrated that VEGF shows several important effects on the neuronal development and physiological function. For example, VEGF accelerates the development of neurons and neural dendritic and axon growth. Besides, VEGF directly and acutely regulates the functions of multiple ion channels of the neuron membrane and changes neural excitability. In traumatic or ischemic injured brains, VEGF produces neuroprotection, enhances capacity of adult neurogenesis and transformation of astroglial cells into new neurons, which are fundamental basis for re-establishment of neural network. Based on the knowledge obtained from the literatures, we propose that VEGF may play very important roles in neural plasticity in the normal brain, and the reconstruction of neurovascular units and neural repair in the traumatic injured brain. This review mainly focuses on neural activity and repair roles of VEGF in adult mammalian brains. Further study on the mechanism of VEGF's neurobiological effects in the brain will be helpful for understanding the regulation of brain functions and developing new therapeutic strategy for prevention of neurodegeneration of the brain.
Animals ; Astrocytes ; cytology ; Brain Injuries ; physiopathology ; Humans ; Neurogenesis ; Neuronal Plasticity ; Neurons ; cytology ; Vascular Endothelial Growth Factor A ; physiology

This is a study on the cultivation condition in vitro and differentiation of neural stem cells from human embryonic brain in order to find a way to get purified multipotential neural stem cells. The single cells was derived from the three-month embryonic brain digested with trypsin, some cells was frozen, the other cells were expanded with EGF and bFGF, the single-cell-clone was obtained by the way of limited dilution, and the serum was used to induce the cells differentiation. The cells were detected with the method of immunohistochemistry. The results showed that a lot of neurospheres could be seen in the presence of mitogens (both EGF and bFGF) and serum could induce neural stem cells to differentiate into neurons, astrocytes, and oligodendrocytes. These indicate that the survival and proliferation of neural stem cells rely on the cooperation of EGF and bFGF. The neural stem cells can also be harvested from the frozen cells.
Astrocytes ; cytology ; Brain ; cytology ; embryology ; Cell Differentiation ; Cells, Cultured ; Culture Media ; chemistry ; Epidermal Growth Factor ; chemistry ; Fibroblast Growth Factor 2 ; chemistry ; Humans ; Immunohistochemistry ; Neural Stem Cells ; cytology ; Neurons ; cytology ; Oligodendroglia ; Pluripotent Stem Cells ; cytology

Neurogenesis occurs in the adult brain, and neural stem cells (NSCs) reside in the adult central nervous system (CNS). In the adult brain, newly generated neuronal cells would originate from a population of glial cells with stem cells properties, and be involved in processes such as learning and memory, depression, and in regenerative attempts in the diseased brain and after injuries. In human, a recent study reported no evidence of migrating neural progenitor cells along the subventricular zone (SVZ) to the olfactory bulb (OB), contrary to other species, highlighting the particularity of adult neurogenesis in human. Though the origin and contribution of newly generated neuronal cells to CNS pathophysiology remain to be fully understood, the discovery that NSCs reside in the adult CNS force us to re-evaluate our knowledge and understanding of brain functioning, and suggest that the adult CNS may be amenable to repair. In this manuscript,we will review the recent data, debates and controversies on the identification, origin and function of newly generated neuronal cells in the adult brain, in human and in other species. We will discuss their contribution and significance to CNS pathophysiology, and for cellular therapy.
Adult Stem Cells ; cytology ; transplantation ; Aging ; Animals ; Brain ; cytology ; Central Nervous System ; cytology ; growth & development ; Central Nervous System Diseases ; pathology ; surgery ; Humans ; Stem Cell Transplantation ; methods

OBJECTIVETo investigate the cell proliferation and differentiation in the developing brain of mouse.

METHODSC57/BL6 mice were divided into 3 groups at random. Bromodeoxyuridine (BrdU) was injected into the brains in different development periods once a day for 7 d. The brains were retrieved 4 weeks after the last BrdU injection. Immunohistochemical and immunofluorescent studies were carried out for detecting cell proliferation (BrdU) and cell differentiation (NeuN, APC, Iba1, and S100beta), respectively.

RESULTSThe number of BrdU labeled cells decreased significantly with the development of the brain. Cell proliferation was prominent in the cortex and striatum. A small portion of BrdU and NeuN double labeled cells could be detected in the cortex at the early stage of development, and in the striatum and CA of the hippocampus in all groups. The majority of BrdU labeled cells were neuroglia, and the number of neuroglia cells decreased dramatically with brain maturation. Neurogenesis is the major cytogenesis in the dentate gyrus.

CONCLUSIONThese results demonstrated that cell proliferation, differentiation and survival were age and brain region related.

Animals ; Animals, Newborn ; Brain ; cytology ; growth & development ; Bromodeoxyuridine ; Cell Count ; Cell Differentiation ; physiology ; Cell Proliferation ; Cerebral Cortex ; cytology ; growth & development ; Corpus Striatum ; cytology ; growth & development ; Fluorescent Antibody Technique ; Hippocampus ; cytology ; growth & development ; Male ; Mice ; Mice, Inbred C57BL ; Nerve Tissue Proteins ; metabolism ; Neuroglia ; cytology ; physiology ; Neurons ; cytology ; physiology ; Nuclear Proteins ; metabolism

In order to explore if mature neurons derived from neural stem cells have the potentiality to divide, we utilized the chemical digestion method to disperse the adult rat brain tissue into single cells, and culture them in serum-free medium. After being cultured for about eight days in vitro, the neural stem cells were induced to differentiate into neurons. The neurons were further induced to divide. Utilizing the method of serial photograph and NF-160 immunocytochemistry, the processes of division of some neurons were recorded. At the same time, PCNA+NF-160 (or Chat, GABA, GAD) double label were used to investigate if the dividing-neurons were mature ones. After the neural stem cells were induced to differentiate in vitro for eight days, they possessed the shape and character of mature neurons. The differentiated neuron had a big nucleus and one or two distinct nucleolus in the nuclear. Within the perikaryon,there were a large amount of dense and Nissl body-like structure. Several long processes emerged from various locations of the cell body. Then, EGF and bFGF were added into the medium to induce division. After two days of induced-division, neuron-like cells were observed to divide; moreover, the number of neuron-like cells in the region increased continually. Immunocytochemistry demonstrated these cells were NF-160-positive. Serial photographs of dividing-process of neuron-like cells were obtained and their daughter cells were also NF-160-positive. After PCNA+NF-160 (or Chat, GABA, GAD) double label, some cells showed brown cell plasma and black nucleus. The above-mentioned results indicate that neurons, which were previously thought to be end-differentiated, can be re-called into cell cycle under appropriate conditions. Mature neurons still have the potential to divide, proliferate and self-renew.
Animals ; Brain ; cytology ; Cell Differentiation ; Cell Division ; Cell Separation ; Cells, Cultured ; Epidermal Growth Factor ; pharmacology ; Fibroblast Growth Factor 2 ; pharmacology ; Neurons ; cytology ; Photography ; methods ; Proliferating Cell Nuclear Antigen ; pharmacology ; Rats ; Rats, Wistar ; Stem Cells ; cytology

Previous genetic fate-mapping studies have indicated that embryonic glial fibrillary acidic protein-positive (GFAP) cells are multifunctional progenitor/neural stem cells that can produce astrocytes as well as neurons and oligodendrocytes throughout the adult mouse central nervous system (CNS). However, emerging evidence from recent studies indicates that GFAP cells adopt different cell fates and generate different cell types in different regions. Moreover, the fate of GFAP cells in the young adult mouse CNS is not well understood. In the present study, hGFAP-Cre/R26R transgenic mice were used to investigate the lineage of embryonic GFAP cells in the young adult mouse CNS. At postnatal day 21, we found that GFAP cells mainly generated NeuN neurons in the cerebral cortex (both ventral and dorsal), hippocampus, and cerebellum. Strangely, these cells were negative for the Purkinje cell marker calbindin in the cerebellum and the neuronal marker NeuN in the thalamus. Thus, contrary to previous studies, our genetic fate-mapping revealed that the cell fate of embryonic GFAP cells at the young adult stage is significantly different from that at the adult stage.
Animals ; Astrocytes ; cytology ; metabolism ; Brain ; cytology ; growth & development ; metabolism ; Calbindins ; metabolism ; Glial Fibrillary Acidic Protein ; metabolism ; Mice ; Mice, Transgenic ; Nerve Tissue Proteins ; metabolism ; Neural Stem Cells ; cytology ; metabolism ; Neurons ; cytology ; metabolism ; Nuclear Proteins ; metabolism

It is well established that neural stem cells (NSCs) are not randomly distributed throughout the brain, but rather are concentrated around blood vessels. Although NSCs lie in a vascular niche, there is no direct evidence for a functional relationship between the NSCs and blood vessel component cells. It is reported that endothelial cells release soluble factors that stimulate the self-renewal of NSCs, inhibit their differentiation, and enhance their neuron production. Endothelial coculture can activate Notch to promote self-renewal. Furthermore, vascular endothelial growth factor (VEGF) plays a significant role in neural cells; it stimulates the growth and differentiation of astrocytes in the central nervous system (CNS). Therefore, beyond their traditional role as structural components of blood vessels, endothelial cells are not only critical component of the neural stem cell niche, but they also are able to enhance neurogenesis, possibly through the secretion of brain-derived neurotrophic factor.
Brain-Derived Neurotrophic Factor ; secretion ; Cell Differentiation ; physiology ; Cell Proliferation ; Cells, Cultured ; Coculture Techniques ; Endothelial Cells ; cytology ; physiology ; Humans ; Neurons ; cytology ; Stem Cells ; cytology ; Vascular Endothelial Growth Factor A ; physiology

OBJECTIVETo investigate the properties of voltage-gated sodium (Na+) channels in developing auditory neurons during early postnatal stages in the mammalian central nervous system.

METHODSUsing the whole-cell voltage-clamp technique, we have studied changes in the electrophysiological properties of Na+ channels in the principal neurons of the medial nucleus of the trapezoid body (MNTB).

RESULTSWe found that MNTB neurons already express functional Na+ channels at postnatal day 1 (P1), and that channel density begins to increase at P5 when the neurons receive synaptic innervation and reach its maximum (approximately 3 fold) at P11 when functional hearing onsets. These changes were paralleled by an age-dependent acceleration in both inactivation and recovery from inactivation. In contrast, there was very little alteration in the voltage-dependence of inactivation.

CONCLUSIONThese profound changes in the properties of voltage-gated Na+ channels may increase the excitability of MNTB neurons and enhance their phase-locking fidelity and capacity during high-frequency synaptic transmission.

Age Factors ; Animals ; Animals, Newborn ; Auditory Pathways ; growth & development ; physiology ; Brain Stem ; cytology ; growth & development ; physiology ; Cochlear Nucleus ; growth & development ; physiology ; Electrophysiology ; Ion Channel Gating ; physiology ; Mice ; Neurons ; physiology ; Patch-Clamp Techniques ; Sodium Channels ; physiology

Transient cerebral ischemia/reperfusion rat model was adopted, and the method of HE staining, TUNEL staining (TdT-mediated dUTP Nick End Labeling) were used to observe the effect of electroacupuncture (EA) and basic fibroblast growth factor (bFGF) on neuronal death. The results evinced that the combination of EA and bFGF could evidently reduce the neuronal death, including both necrosis and apoptosis, compared with EA or bFGF application alone. It is suggested that bFGF and EA can complement each other and enhance the protective effect following cerebral ischemia.
Animals ; Apoptosis ; Brain Ischemia ; therapy ; Electroacupuncture ; Fibroblast Growth Factor 2 ; pharmacology ; In Situ Nick-End Labeling ; Neurons ; cytology ; drug effects ; Neuroprotective Agents ; pharmacology ; Rats

Brain-derived neurotrophic factor (BDNF) can promote developmental competence in mammalian oocytes during in vitro maturation (IVM), but the role of BDNF in oocyte maturation at cellular level is not still clear. In this study, mouse cumulus-enclosed oocytes subjected to IVM were fertilized and cultured to blastocyst stage. Meiotic spindle configuration and cortical granules distribution during oocyte maturation in vitro were assessed by using immunofluorescence and laser confocal microscopy. The results showed that BDNF contributed to the complete preimplantation development of mouse oocytes compared to the control oocytes (13.78% vs. 5.92%; P<0.05). Further, BDNF did not accelerate nuclear maturation of IVM oocytes. For the BDNF-treated oocytes at meiosis I, Meiotic spindle areas were significantly smaller and the number of cytoplasmic microtubule organizing centers was greater than that in the control, and the percentages of oocytes showed spindles positioned near the oolemma and a well-formed cortical granule-free domain were significantly higher than that of the control. These morphological characteristics of the BDNF-treated oocytes were much closer to the oocytes matured in vivo than those of the control oocytes. In conclusion, BDNF can promote the developmental competence of mouse IVM oocytes, by improving the meiotic spindle configuration and location and cortical granules distribution at meiosis 1.
Animals ; Blastomeres ; cytology ; Brain-Derived Neurotrophic Factor ; pharmacology ; Female ; Fertilization in Vitro ; In Vitro Oocyte Maturation Techniques ; methods ; Male ; Mice ; Oocysts ; growth & development