Search results for "NEUROGENESIS"
showing 10 items of 336 documents
Adult Neurogenesis in Reptiles
2011
Adult neurogenesis in reptiles is a well-documented phenomenon and exists in many telencephalic areas. The newly generated neurons originate along the walls of the lateral ventricles, mainly in the sulci. The putative neural progenitors are radial glial cells. These glial cells give rise to neuroblasts that migrate to their final destination. In general, the new neurons are born in the portion of the ventricular zone (VZ) adjacent to the telencephalic area where they will be recruited and migrate radially through the brain parenchyma along the processes of radial glial cells to their final destination, although migration to the olfactory bulbs (OB) is different. Specifically, it seems that …
Migrating neuroblasts of the rostral migratory stream are putative targets for the action of nitric oxide
2007
It has been demonstrated that the gaseous messenger nitric oxide influences cell proliferation and cell migration, and therefore affects adult neurogenesis in mammals. Here, we investigated the putative targets for this action in the rostral migratory stream of the rat. We used immunocytochemical detection of the beta1 subunit of the enzyme soluble guanylyl cyclase, which can be activated by nitric oxide. Our results under light and electron microscopy demonstrated that the migrating neuroblasts (type A cells) were beta1-immunopositive. The astrocytes (type B cells), immature precursors (type C cells) and ependymal cells (type E cells) were beta1-immunonegative. The neurochemical characteri…
Binge administration of 3,4-methylenedioxymethamphetamine ("ecstasy") impairs the survival of neural precursors in adult rat dentate gyrus.
2006
3,4-Methylenedioxymethamphetamine (MDMA) is a potent stimulant and hallucinogenic drug whose ability to regulate neurogenesis in the adult has not been previously investigated. We used 5'-bromo-2-deoxyuridine (BrdU) and Ki-67 as mitotic markers, and doublecortin (DCX) as a marker of immature neurons, to study proliferation, survival and maturation of adult-generated cells in the dentate gyrus (DG) of the hippocampus following binge administration of MDMA (8 injections of 5 mg/kg at 6 h intervals). The results showed that MDMA treatment did not affect cytogenesis in the DG, but significantly decreased the survival rate of cells incorporated after 2 weeks to the granular layer of the DG by ca…
Neuroplasticity and environment: A pharmacotherapeutic approach toward preclinical and clinical understanding
2021
International audience; Emerging research in the field of behavioral neuroscience has demonstrated the fundamental role of the cerebral organization. For brain development, various important functions are required for instance synaptic plasticity and neurogenesis. This property is described in terms of neuroplasticity. Neuroplasticity denotes the extraordinary ability of the brain for the recognition of its structure and function after an experience with some external stimuli and involves in the various behavioral processes of the brain such as cognitive functions. It has multiple factors that can range from gene alteration to environmental factors. Environmental factors exert both negative…
Astrocytes give rise to new neurons in the adult mammalian hippocampus
2001
Neurogenesis in the dentate gyrus of the hippocampus persists throughout life in many vertebrates, including humans. The progenitors of these new neurons reside in the subgranular layer (SGL) of the dentate gyrus. Although stem cells that can self-renew and generate new neurons and glia have been cultured from the adult mammalian hippocampus, the in vivo primary precursors for the formation of new neurons have not been identified. Here we show that SGL cells, which express glial fibrillary acidic protein and have the characteristics of astrocytes, divide and generate new neurons under normal conditions or after the chemical removal of actively dividing cells. We also describe a population o…
Glutathione and cellular redox control in epigenetic regulation.
2015
Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. Over recent years, growing evidence has suggested a link between redox metabolism and the control of epigenetic mechanisms. The effect of the redox control, oxidative stress, and glutathione (GSH) on the epigenetic mechanisms occur at different levels affecting DNA methylation, miRNAs expression, and histone post-translational modifications (PTMs). Furthermore, a number of redox PTMs are being described, so enriching the histone code. Pioneer works showed how oxidized GSH inhibits the activity of S-adenosyl methionine synthetase, MAT1A, a key en…
In vivo and ex vivo magnetic resonance spectroscopy of the infarct and the subventricular zone in experimental stroke
2015
Ex vivo high-resolution magic-angle spinning (HRMAS) provides metabolic information with higher sensitivity and spectral resolution than in vivo magnetic resonance spectroscopy (MRS). Therefore, we used both techniques to better characterize the metabolic pattern of the infarct and the neural progenitor cells (NPCs) in the ipsilateral subventricular zone (SVZi). Ischemic stroke rats were divided into three groups: G0 (non-stroke controls, n = 6), G1 (day 1 after stroke, n = 6), and G7 (days 6 to 8 after stroke, n =12). All the rats underwent MRS. Three rats per group were analyzed by HRMAS. The remaining rats were used for immunohistochemical studies. In the infarct, both techniques detect…
Development of the GABAergic system from birth to adolescence.
2011
The neurotransmitter GABA (γ-aminobutyric acid), acting via inotropic GABAA and metabotropic GABAB receptors, plays an essential role in a variety of distinct neuronal processes, including regulation of neuronal excitability, determination of temporal aspects of spike trains, control of the size and propagation of neuronal assemblies, generation of oscillatory activity, and neuronal plasticity. Although the developmental switch between excitatory and inhibitory GABAA receptor–mediated responses is widely appreciated, the fact that the postnatal maturation of the GABAergic system lasts until late adolescence is not so persuasively promoted. This review summarizes recent knowledge of the mat…
PSA-NCAM is expressed in immature, but not recently generated, neurons in the adult cat cerebral cortex layer II
2011
Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the …
Calretinin/PSA-NCAM immunoreactive granule cells after hippocampal damage produced by kainic acid and DEDTC treatment in mouse.
2003
There is a dramatic increase in the number of lightly immunoreactive calretinin cells in the granular layer of the dentate gyrus of the mouse hippocampus 1 day after excitotoxic injury using kainic acid combined with the zinc chelator diethyldithiocarbamate. At 7 days after treatment, these cells are strongly immunoreactive for calretinin and for the polysialated form of the glycoprotein neural cell adhesion molecule (PSA-NCAM). The reexpression of calretinin and PSA-NCAM after treatment corresponds well with the loss of input from the damaged hilar mossy cells. These cells could be considered immature granule cells since they are immunoreactive to markers for immature cells such as PSA-NCA…