Repetitive traumatic brain injury impacts adult neurogenesis in the hippocampal dentate gyrus,leading to long-term cognitive impairment.However,the mechanism underlying this neurogenesis impairment remains unknown.In ...Repetitive traumatic brain injury impacts adult neurogenesis in the hippocampal dentate gyrus,leading to long-term cognitive impairment.However,the mechanism underlying this neurogenesis impairment remains unknown.In this study,we established a male mouse model of repetitive traumatic brain injury and performed long-term evaluation of neurogenesis of the hippocampal dentate gyrus after repetitive traumatic brain injury.Our results showed that repetitive traumatic brain injury inhibited neural stem cell proliferation and development,delayed neuronal maturation,and reduced the complexity of neuronal dendrites and spines.Mice with repetitive traumatic brain injuryalso showed deficits in spatial memory retrieval.Moreover,following repetitive traumatic brain injury,neuroinflammation was enhanced in the neurogenesis microenvironment where C1q levels were increased,C1q binding protein levels were decreased,and canonical Wnt/β-catenin signaling was downregulated.An inhibitor of C1 reversed the long-term impairment of neurogenesis induced by repetitive traumatic brain injury and improved neurological function.These findings suggest that repetitive traumatic brain injury–induced C1-related inflammation impairs long-term neurogenesis in the dentate gyrus and contributes to spatial memory retrieval dysfunction.展开更多
Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infectio...Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.展开更多
The cases of landing and impact of the heavy rain of typhoon in Fujian are analyzed. From the research of the mainly weather systems which caused heavy rain and the distribution characteristics of atmospheric circulat...The cases of landing and impact of the heavy rain of typhoon in Fujian are analyzed. From the research of the mainly weather systems which caused heavy rain and the distribution characteristics of atmospheric circulation situation field, we conclude that on the basis of Fujian special geographical location and terrain, there are four types (easterly jet, warm-type sheer, inverted V-shaped trough of typhoon, westerly trough) are conductive to the circulation patterns of causing the heavy rain of typhoon. Through studying a number of typical model cases of heavy rain of typhoon, we can reveal the mechanism which causes the heavy rain of typhoon by the mostly influencing systems in different circulation backgrounds and the causes of the heavy rain of typhoon.展开更多
Based on the ERA5 reanalysis data and the surface observations from automatic weather stations, a comparative analysis has been conducted toinvestigate the differences in heavy rainfall distributions caused by two lan...Based on the ERA5 reanalysis data and the surface observations from automatic weather stations, a comparative analysis has been conducted toinvestigate the differences in heavy rainfall distributions caused by two landfalling tropical cyclones (TCs): LUPIT (2109) and LISA (9610). Thetwo TCs have similar tracks, intensity and landing points, but show different asymmetric features in their rainstorm location relative to their tracks.The results indicate that the TC rainfall differences are mainly caused by different rainstorm formation mechanisms. The wind shear contributesmost to the rainstorm of LISA, while land-sea contrast and topographical effect are the main factors of LUPIT rainstorm. Under the influence ofstrong environmental vertical wind shear and the weak cold air invasion from the west, the circulation center of LISA tilts westward with height,which cooperates with the low-level water vapor convergence and vertical ascending movement on the western side of the TC center to jointlycause the heavy rainstorm to the west of LISA center. In contrast, LUPIT has weak environmental vertical wind shear and no obvious structuretilting with height. Topographic effect plays a crucial role in causing the heavy rainstorm on the north of TC center. The southeasterly jet isblocked by the Taimu Mountain in the northeastern Fujian Province, and the strong ascending motion caused by the terrain-induced convergenceappears to the north of LUPIT center. In addition, the moisture convergence is more pronounced in the north and weaker in the south. Theintrusion of weak cold air from the east to the coastal areas of central-northern Fujian, and the moisture-convergence distribution, jointly cause theheavy rainstorm to the north of LUPIT.展开更多
基金supported by the Fundamental Research Program of Shanxi Province of China,No.20210302124277the Science Foundation of Shanxi Bethune Hospital,No.2021YJ13(both to JW)。
文摘Repetitive traumatic brain injury impacts adult neurogenesis in the hippocampal dentate gyrus,leading to long-term cognitive impairment.However,the mechanism underlying this neurogenesis impairment remains unknown.In this study,we established a male mouse model of repetitive traumatic brain injury and performed long-term evaluation of neurogenesis of the hippocampal dentate gyrus after repetitive traumatic brain injury.Our results showed that repetitive traumatic brain injury inhibited neural stem cell proliferation and development,delayed neuronal maturation,and reduced the complexity of neuronal dendrites and spines.Mice with repetitive traumatic brain injuryalso showed deficits in spatial memory retrieval.Moreover,following repetitive traumatic brain injury,neuroinflammation was enhanced in the neurogenesis microenvironment where C1q levels were increased,C1q binding protein levels were decreased,and canonical Wnt/β-catenin signaling was downregulated.An inhibitor of C1 reversed the long-term impairment of neurogenesis induced by repetitive traumatic brain injury and improved neurological function.These findings suggest that repetitive traumatic brain injury–induced C1-related inflammation impairs long-term neurogenesis in the dentate gyrus and contributes to spatial memory retrieval dysfunction.
基金Hubei Natural Science Foundation of China,Grant/Award Number:2024AFB593。
文摘Background:Rabies virus(RABV)-derived neuronal tracing tools are extensively applied in retrograde tracing due to their strict retrograde transsynaptic transfer property and low neurotoxicity.However,the RABV infection and expression of fluorescence products would be gradually cleared while the infected neurons still survive,a phenomenon known as non-cytolytic immune clearance(NCLIC).This phenomenon introduced the risk of fluorescence loss and led to the omission of a subset of neurons that should be labeled,thereby interfering in the analysis of tracing results.Methods:To compensate for the fluorescence loss problem,in this study,we developed a novel marker footprints(MF)mouse,involving a Cre recombinase-dependent red fluorescent reporter system and systemic expression of glycoprotein(G)and ASLV-A receptor(TVA).Using this mouse model combined with the well-developed RABV-EnvA-ΔG-GFP-Cre viral tool,we developed a novel green-to-red spectral labeling strategy.Results:Neurons in the MF mouse could be co-labeled with green fluorescence from the very quick expression of the viral tool and with red fluorescence from the relatively slow expression of the neuron itself,so neurons undergoing NCLIC with green fluorescence loss could be relabeled red.Furthermore,newly infected neurons could be labeled green and other neurons could be labeled yellow due to the temporal expression difference between the two fluorescent proteins.Conclusions:This is the first polysynaptic retrograde tracing labeling strategy that could label neurons using spectral fluorescence colors with only one injection of the viral tool,enabling its application in recognizing the labeling sequence of neurons in brain regions and enhancing the spatiotemporal resolution of neuronal tracing.
文摘The cases of landing and impact of the heavy rain of typhoon in Fujian are analyzed. From the research of the mainly weather systems which caused heavy rain and the distribution characteristics of atmospheric circulation situation field, we conclude that on the basis of Fujian special geographical location and terrain, there are four types (easterly jet, warm-type sheer, inverted V-shaped trough of typhoon, westerly trough) are conductive to the circulation patterns of causing the heavy rain of typhoon. Through studying a number of typical model cases of heavy rain of typhoon, we can reveal the mechanism which causes the heavy rain of typhoon by the mostly influencing systems in different circulation backgrounds and the causes of the heavy rain of typhoon.
文摘Based on the ERA5 reanalysis data and the surface observations from automatic weather stations, a comparative analysis has been conducted toinvestigate the differences in heavy rainfall distributions caused by two landfalling tropical cyclones (TCs): LUPIT (2109) and LISA (9610). Thetwo TCs have similar tracks, intensity and landing points, but show different asymmetric features in their rainstorm location relative to their tracks.The results indicate that the TC rainfall differences are mainly caused by different rainstorm formation mechanisms. The wind shear contributesmost to the rainstorm of LISA, while land-sea contrast and topographical effect are the main factors of LUPIT rainstorm. Under the influence ofstrong environmental vertical wind shear and the weak cold air invasion from the west, the circulation center of LISA tilts westward with height,which cooperates with the low-level water vapor convergence and vertical ascending movement on the western side of the TC center to jointlycause the heavy rainstorm to the west of LISA center. In contrast, LUPIT has weak environmental vertical wind shear and no obvious structuretilting with height. Topographic effect plays a crucial role in causing the heavy rainstorm on the north of TC center. The southeasterly jet isblocked by the Taimu Mountain in the northeastern Fujian Province, and the strong ascending motion caused by the terrain-induced convergenceappears to the north of LUPIT center. In addition, the moisture convergence is more pronounced in the north and weaker in the south. Theintrusion of weak cold air from the east to the coastal areas of central-northern Fujian, and the moisture-convergence distribution, jointly cause theheavy rainstorm to the north of LUPIT.
