Introduction of neurogenesis： Neurogenesis is a process charac- terized by the production and differentiation of new neurons from neural stem cells （Emsley et al., 2005）. This was previously thought to occur in pre...Introduction of neurogenesis： Neurogenesis is a process charac- terized by the production and differentiation of new neurons from neural stem cells （Emsley et al., 2005）. This was previously thought to occur in prenatal and early postnatal development only; how- ever, several studies have shown that it occurs continuously in our adult brains as well, mainly in the lateral ventricles of the brain, the lining of the subventricular zone （SVZ）, and the subgranular zone （SGZ） of the dentate gyrus （part of the hippocampal complex）. Neurogenesis may also be induced in the adult brain by injury or degeneration of the central nervous system （CNS）. In this instance, new neurons have been found in other parts of the brain, such as in the neocortex, amygdala, substantia nigra and tegmentum of the midrain, the brain stem and spinal cord （Wang and Jin, 2014）. There are numerous steps involved in differentiating neural stem cells into fully-grown neurons, starting with stem cell proliferation, then migration and survival, followed by commitment to neuronal lineage, and lastly the assimilation of the new neurons into existing brain circuits, ranging from up in the neocortex to down in the spinal cord. Neurogenesis is a dynamic process that is modulated by several factors, both intrinsic and extrinsic, such as growth and transcriptional factors, cell surface receptors, signal transduction molecules, and cytokine or chemokines. In adult brains, physio- logical as well as pathological conditions can affect neurogenesis. Neural stem cell proliferation and neuronal differentiation can be inhibited by infection or invoked inflammation. The interruption of neurogenesis in adult brains leads to hippocampus-dependent learning and behavior impairment （Yan et al., 2007）.展开更多
文摘Introduction of neurogenesis： Neurogenesis is a process charac- terized by the production and differentiation of new neurons from neural stem cells （Emsley et al., 2005）. This was previously thought to occur in prenatal and early postnatal development only; how- ever, several studies have shown that it occurs continuously in our adult brains as well, mainly in the lateral ventricles of the brain, the lining of the subventricular zone （SVZ）, and the subgranular zone （SGZ） of the dentate gyrus （part of the hippocampal complex）. Neurogenesis may also be induced in the adult brain by injury or degeneration of the central nervous system （CNS）. In this instance, new neurons have been found in other parts of the brain, such as in the neocortex, amygdala, substantia nigra and tegmentum of the midrain, the brain stem and spinal cord （Wang and Jin, 2014）. There are numerous steps involved in differentiating neural stem cells into fully-grown neurons, starting with stem cell proliferation, then migration and survival, followed by commitment to neuronal lineage, and lastly the assimilation of the new neurons into existing brain circuits, ranging from up in the neocortex to down in the spinal cord. Neurogenesis is a dynamic process that is modulated by several factors, both intrinsic and extrinsic, such as growth and transcriptional factors, cell surface receptors, signal transduction molecules, and cytokine or chemokines. In adult brains, physio- logical as well as pathological conditions can affect neurogenesis. Neural stem cell proliferation and neuronal differentiation can be inhibited by infection or invoked inflammation. The interruption of neurogenesis in adult brains leads to hippocampus-dependent learning and behavior impairment （Yan et al., 2007）.
