Sensitive smell discrimination is based on structural plasticity of the olfactory bulb,which depends on migration and integration of newborn neurons from the subventricular zone.In this study,we examined the relations...Sensitive smell discrimination is based on structural plasticity of the olfactory bulb,which depends on migration and integration of newborn neurons from the subventricular zone.In this study,we examined the relationship between neural stem cell status in the subventricular zone and olfactory function in rats with diabetes mellitus.Streptozotocin was injected through the femoral vein to induce type 1 diabetes mellitus in Sprague-Dawley rats.Two months after injection,olfactory sensitivity was decreased in diabetic rats.Meanwhile,the number of Brd U-positive and Brd U＋/DCX＋double-labeled cells was lower in the subventricular zone of diabetic rats compared with agematched normal rats.Western blot results revealed downregulated expression of insulin receptorβ,phosphorylated glycogen synthase kinase 3β,and β-catenin in the subventricular zone of diabetic rats.Altogether,these results indicate that diabetes mellitus causes insulin deficiency,which negatively regulates glycogen synthase kinase 3β and enhances β-catenin degradation,with these changes inhibiting neural stem cell proliferation.Further,these signaling pathways affect proliferation and differentiation of neural stem cells in the subventricular zone.Dysfunction of subventricular zone neural stem cells causes a decline in olfactory bulb structural plasticity and impairs olfactory sensitivity in diabetic rats.展开更多
Traumatic brain injury （TBI） is the leading cause of death and disability of persons under 45 years old in the United States, affecting over 1.5 million individtials each year. It had been th ought that recovery fro...Traumatic brain injury （TBI） is the leading cause of death and disability of persons under 45 years old in the United States, affecting over 1.5 million individtials each year. It had been th ought that recovery from such injuries is severely limited due to the inability of the adult bra in to replace damaged neurons. However, recent studies indicate that the mature mammalian central nervous system （CNS） has the potential to replenish damaged neurons by proliferation and neuronal differentiation of adult neural stem/progenitor cells residing in the neurogenic regions in the brain. Furthermore, increasing evidence indicates that these endogenous stem/ progenitor cells may play regenerative and reparative roles in response to CNS injuries or diseases. In support of this notion, heightened levels of cell proliferation and neurogenesis have been ob- served in response to brain trauma or insults suggesting that the brain has the inherent potential to restore populations of damaged or destroyed neurons. This review will discuss the potential functions of adult neurogenesis and recent development of strategies aiming at harnessing this neurogenic capacity in order to repopulate and repair the injured brain.展开更多
The discovery that new neurons are produced in some regions of the adult mammalian brain is a paradigm-shift in neuroscience research.These new-born cells are produced from neuroprogenitors mainly in the subventricula...The discovery that new neurons are produced in some regions of the adult mammalian brain is a paradigm-shift in neuroscience research.These new-born cells are produced from neuroprogenitors mainly in the subventricular zone at the margin of the lateral ventricle,subgranular zone in the hippocampal dentate gyrus and in the striatum,a component of the basal ganglia,even in humans.In the human hippocampus,neuroblasts are produced even in elderlies.The regulation of adult neurogenesis is a complex phenomenon involving a multitude of molecules,neurotransmitters and soluble factors released by different sources including glial cells.Microglia,the resident macrophages of the central nervous system,are considered to play an important role on the regulation of adult neurogenesis both in physiological and pathological conditions.Following stroke and other acute neural disorders,there is an increase in the numbers of neuroblast production in the neurogenic niches.Microglial activation is believed to display both beneficial and detrimental role on adult neurogenesis after stroke,depending on the activation level and brain location.In this article,we review the scientific evidence addressing the role of microglial activation on adult neurogenesis after ischemia.A comprehensive understanding of the microglial role after stroke and other neural disorders it is an important step for development of future therapies based on manipulation of adult neurogenesis.展开更多
Neurogenesis is the process by which cells divide, migrate, and subsequently differentiate into a neuronal phenotype. Significant rates of neurogenesis persist into adulthood in two brain regions, the subgranular zone...Neurogenesis is the process by which cells divide, migrate, and subsequently differentiate into a neuronal phenotype. Significant rates of neurogenesis persist into adulthood in two brain regions, the subgranular zone of the dentate gyrus and the subventricular zone of the lateral ventricles. Cells of the subventricular zone divide and migrate via the rostral migratory stream to the olfactory bulb where they differentiate into granule and pefiglomerular cells. With the discovery of large-sca^e neurogenesis in the adult brain, there have been significant efforts to identify the mechanisms that control this process as well as the role of these cells in neuronal functioning. Although many questions remain unanswered, new insights appear daily about adult neurogenesis, regulatory mechanisms, and the fates of the progeny. In this review we highlight the main studies investigating factors that regulate neurogenesis in the subventricular zone, neuronal migration to the olfactory bulb, neuronal integration into the existing bulbar network and shortly discuss the functional meaning of this process.展开更多
基金partly supported by the National Natural Science Foundation of China,No.81370448,81570725
文摘Sensitive smell discrimination is based on structural plasticity of the olfactory bulb,which depends on migration and integration of newborn neurons from the subventricular zone.In this study,we examined the relationship between neural stem cell status in the subventricular zone and olfactory function in rats with diabetes mellitus.Streptozotocin was injected through the femoral vein to induce type 1 diabetes mellitus in Sprague-Dawley rats.Two months after injection,olfactory sensitivity was decreased in diabetic rats.Meanwhile,the number of Brd U-positive and Brd U＋/DCX＋double-labeled cells was lower in the subventricular zone of diabetic rats compared with agematched normal rats.Western blot results revealed downregulated expression of insulin receptorβ,phosphorylated glycogen synthase kinase 3β,and β-catenin in the subventricular zone of diabetic rats.Altogether,these results indicate that diabetes mellitus causes insulin deficiency,which negatively regulates glycogen synthase kinase 3β and enhances β-catenin degradation,with these changes inhibiting neural stem cell proliferation.Further,these signaling pathways affect proliferation and differentiation of neural stem cells in the subventricular zone.Dysfunction of subventricular zone neural stem cells causes a decline in olfactory bulb structural plasticity and impairs olfactory sensitivity in diabetic rats.
文摘Traumatic brain injury （TBI） is the leading cause of death and disability of persons under 45 years old in the United States, affecting over 1.5 million individtials each year. It had been th ought that recovery from such injuries is severely limited due to the inability of the adult bra in to replace damaged neurons. However, recent studies indicate that the mature mammalian central nervous system （CNS） has the potential to replenish damaged neurons by proliferation and neuronal differentiation of adult neural stem/progenitor cells residing in the neurogenic regions in the brain. Furthermore, increasing evidence indicates that these endogenous stem/ progenitor cells may play regenerative and reparative roles in response to CNS injuries or diseases. In support of this notion, heightened levels of cell proliferation and neurogenesis have been ob- served in response to brain trauma or insults suggesting that the brain has the inherent potential to restore populations of damaged or destroyed neurons. This review will discuss the potential functions of adult neurogenesis and recent development of strategies aiming at harnessing this neurogenic capacity in order to repopulate and repair the injured brain.
基金supported by the Brazilian National Council for Scientific Research。
文摘The discovery that new neurons are produced in some regions of the adult mammalian brain is a paradigm-shift in neuroscience research.These new-born cells are produced from neuroprogenitors mainly in the subventricular zone at the margin of the lateral ventricle,subgranular zone in the hippocampal dentate gyrus and in the striatum,a component of the basal ganglia,even in humans.In the human hippocampus,neuroblasts are produced even in elderlies.The regulation of adult neurogenesis is a complex phenomenon involving a multitude of molecules,neurotransmitters and soluble factors released by different sources including glial cells.Microglia,the resident macrophages of the central nervous system,are considered to play an important role on the regulation of adult neurogenesis both in physiological and pathological conditions.Following stroke and other acute neural disorders,there is an increase in the numbers of neuroblast production in the neurogenic niches.Microglial activation is believed to display both beneficial and detrimental role on adult neurogenesis after stroke,depending on the activation level and brain location.In this article,we review the scientific evidence addressing the role of microglial activation on adult neurogenesis after ischemia.A comprehensive understanding of the microglial role after stroke and other neural disorders it is an important step for development of future therapies based on manipulation of adult neurogenesis.
文摘Neurogenesis is the process by which cells divide, migrate, and subsequently differentiate into a neuronal phenotype. Significant rates of neurogenesis persist into adulthood in two brain regions, the subgranular zone of the dentate gyrus and the subventricular zone of the lateral ventricles. Cells of the subventricular zone divide and migrate via the rostral migratory stream to the olfactory bulb where they differentiate into granule and pefiglomerular cells. With the discovery of large-sca^e neurogenesis in the adult brain, there have been significant efforts to identify the mechanisms that control this process as well as the role of these cells in neuronal functioning. Although many questions remain unanswered, new insights appear daily about adult neurogenesis, regulatory mechanisms, and the fates of the progeny. In this review we highlight the main studies investigating factors that regulate neurogenesis in the subventricular zone, neuronal migration to the olfactory bulb, neuronal integration into the existing bulbar network and shortly discuss the functional meaning of this process.
基金This work was supported by Grant from National Natural ScienceFoundation of China (30200291, 30170300) and Natural Science Foundation of Shaanxi Province,China(2002C250,2001SM63).
