Synapses are key structures in neural networks,and are involved in learning and memory in the central nervous system.Investigating synaptogenesis and synaptic aging is important in understanding neural development and...Synapses are key structures in neural networks,and are involved in learning and memory in the central nervous system.Investigating synaptogenesis and synaptic aging is important in understanding neural development and neural degeneration in diseases such as Alzheimer disease and Parkinson’s disease.Our previous study found that synaptogenesis and synaptic maturation were harmonized with brain development and maturation.However,synaptic damage and loss in the aging cerebellum are not well understood.This study was designed to investigate the occurrence of synaptic aging in the cerebellum by observing the ultrastructural changes of dendritic spines and synapses in cerebellar Purkinje cells of aging mice.Immunocytochemistry,Di I diolistic assays,and transmission electron microscopy were used to visualize the morphological characteristics of synaptic buttons,dendritic spines and synapses of Purkinje cells in mice at various ages.With synaptic aging in the cerebellum,dendritic spines and synaptic buttons were lost,and the synaptic ultrastructure was altered,including a reduction in the number of synaptic vesicles and mitochondria in presynaptic termini and smaller thin specialized zones in pre-and post-synaptic membranes.These findings confirm that synaptic morphology and function is disrupted in aging synapses,which may be an important pathological cause of neurodegenerative diseases.展开更多
Cold exposure is an external stress factor that causes skin frostbite as well as a variety of diseases.Estrogen might participate in neuroprotection after cold exposure,but its precise mechanism remains unclear.In thi...Cold exposure is an external stress factor that causes skin frostbite as well as a variety of diseases.Estrogen might participate in neuroprotection after cold exposure,but its precise mechanism remains unclear.In this study,mice were exposed to 10°C for 7 days and 0–4°C for 30 days to induce a model of chronic cold exposure.Results showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions,MAP1LC3-labeled autophagic cells,Iba1-labeled activated microglia,and interleukin-1β-positive pyramidal cells were increased in the hippocampal CA1 area.Chronic cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor,G protein-coupled receptor 30.These results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations,including oxidative stress,neuronal autophagy,and neuroimmunoreactivity.Moreover,estrogen exerts a neuroprotective effect on cold exposure.展开更多
To investigate the pattern of neural differentiation and synaptogenesis in the mouse retina, immunolabeling, Brd U assay and transmission electron microscopy were used. We show that the neuroblastic cell layer is the ...To investigate the pattern of neural differentiation and synaptogenesis in the mouse retina, immunolabeling, Brd U assay and transmission electron microscopy were used. We show that the neuroblastic cell layer is the germinal zone for neural differentiation and retinal lamination. Ganglion cells differentiated initially at embryonic day 13（E13）, and at E18 horizontal cells appeared in the neuroblastic cell layer. Neural stem cells in the outer neuroblastic cell layer differentiated into photoreceptor cells as early as postnatal day 0（P0）, and neural stem cells in the inner neuroblastic cell layer differentiated into bipolar cells at P7. Synapses in the retina were mainly located in the outer and inner plexiform layers. At P7, synaptophysin immunostaining appeared in presynaptic terminals in the outer and inner plexiform layers with button-like structures. After P14, presynaptic buttons were concentrated in outer and inner plexiform layers with strong staining. These data indicate that neural differentiation and synaptogenesis in the retina play important roles in the formation of retinal neural circuitry. Our study showed that the period before P14, especially between P0 and P14, represents a critical period during retinal development. Mouse eye opening occurs during that period, suggesting that cell differentiation and synaptic formation lead to the attainment of visual function.展开更多
基金supported by the Science and Technology Projects of Henan Province of China,No.172102310001the Biology Advantage Discipline Fund of Henan Province of China
文摘Synapses are key structures in neural networks,and are involved in learning and memory in the central nervous system.Investigating synaptogenesis and synaptic aging is important in understanding neural development and neural degeneration in diseases such as Alzheimer disease and Parkinson’s disease.Our previous study found that synaptogenesis and synaptic maturation were harmonized with brain development and maturation.However,synaptic damage and loss in the aging cerebellum are not well understood.This study was designed to investigate the occurrence of synaptic aging in the cerebellum by observing the ultrastructural changes of dendritic spines and synapses in cerebellar Purkinje cells of aging mice.Immunocytochemistry,Di I diolistic assays,and transmission electron microscopy were used to visualize the morphological characteristics of synaptic buttons,dendritic spines and synapses of Purkinje cells in mice at various ages.With synaptic aging in the cerebellum,dendritic spines and synaptic buttons were lost,and the synaptic ultrastructure was altered,including a reduction in the number of synaptic vesicles and mitochondria in presynaptic termini and smaller thin specialized zones in pre-and post-synaptic membranes.These findings confirm that synaptic morphology and function is disrupted in aging synapses,which may be an important pathological cause of neurodegenerative diseases.
基金supported by the Henan Province Foundation for Key University Teachers in China,No.16A330001,15A180031the Henan Postdoctoral Foundation in China,No.2015051a grant from the Henan Province Research Program of Basic and Advanced Technology in China,No.162300410102
文摘Cold exposure is an external stress factor that causes skin frostbite as well as a variety of diseases.Estrogen might participate in neuroprotection after cold exposure,but its precise mechanism remains unclear.In this study,mice were exposed to 10°C for 7 days and 0–4°C for 30 days to induce a model of chronic cold exposure.Results showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions,MAP1LC3-labeled autophagic cells,Iba1-labeled activated microglia,and interleukin-1β-positive pyramidal cells were increased in the hippocampal CA1 area.Chronic cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor,G protein-coupled receptor 30.These results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations,including oxidative stress,neuronal autophagy,and neuroimmunoreactivity.Moreover,estrogen exerts a neuroprotective effect on cold exposure.
基金supported by the National Natural Science Foundation of China,No.31070952 and U1204311the Scientific Research Foundation of Henan University of China,No.0000A40475 and 0000A40356
文摘To investigate the pattern of neural differentiation and synaptogenesis in the mouse retina, immunolabeling, Brd U assay and transmission electron microscopy were used. We show that the neuroblastic cell layer is the germinal zone for neural differentiation and retinal lamination. Ganglion cells differentiated initially at embryonic day 13（E13）, and at E18 horizontal cells appeared in the neuroblastic cell layer. Neural stem cells in the outer neuroblastic cell layer differentiated into photoreceptor cells as early as postnatal day 0（P0）, and neural stem cells in the inner neuroblastic cell layer differentiated into bipolar cells at P7. Synapses in the retina were mainly located in the outer and inner plexiform layers. At P7, synaptophysin immunostaining appeared in presynaptic terminals in the outer and inner plexiform layers with button-like structures. After P14, presynaptic buttons were concentrated in outer and inner plexiform layers with strong staining. These data indicate that neural differentiation and synaptogenesis in the retina play important roles in the formation of retinal neural circuitry. Our study showed that the period before P14, especially between P0 and P14, represents a critical period during retinal development. Mouse eye opening occurs during that period, suggesting that cell differentiation and synaptic formation lead to the attainment of visual function.
