Chronic migraine(CM)is a prevalent and highly debilitating neurological disorder.Functional magnetic resonance imaging(fMRI)studies have demonstrated associations between abnormal brain region activation and CM,yet th...Chronic migraine(CM)is a prevalent and highly debilitating neurological disorder.Functional magnetic resonance imaging(fMRI)studies have demonstrated associations between abnormal brain region activation and CM,yet the underlying complex neural circuitry mechanisms remain unclear.The spinal trigeminal nucleus caudalis(Sp5C)serves as the primary central hub for orofacial nociceptive input,receiving trigeminal pain signals and projecting to higher-order centers such as the thalamus.Therefore,we sought to investigate whether the Sp5C region and its associated circuits were involved in CM pathogenesis.In this study,we established a CM mouse model through repeated intraperitoneal injections of nitroglycerin(NTG).Using a combination of in vivo fiber photometry and in vitro c-Fos immunohistochemistry,we found a marked periorbital and plantar mechanical allodynia in CM mice,accompanied by increased glutamatergic neuronal activity in Sp5C.Chemogenetic manipulation of Sp5C glutamatergic neurons(Sp5CV^(glut2))bidirectionally modulated migraine-like behaviors and induced pain-related affective states,as evidenced by conditioned place preference/aversion(CPP/CPA)paradigms.Anterograde viral tracing revealed dense projections from Sp5C^(Vglut2)to the subthalamic nucleus(STN),which was activated in CM mice.Optogenetic activation of the Sp5C-STN pathway similarly produced migraine-like behaviors and pain-related aversive memory in mice.Altogether,we revealed a critical role of the Sp5CVglut2-STN circuit in the development and modulation of CM.Our findings provide novel mechanistic insights into the central mechanisms underlying CM,establishing potential theoretical foundations for clinical diagnosis and therapeutic development.展开更多
A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,...A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.展开更多
This study aimed to identify the physiological mechanisms enabling low-N-tolerant maize cultivar to maintain higher photosynthesis and yield under low-N,low-light,and combined stress.In a three-year field trial of low...This study aimed to identify the physiological mechanisms enabling low-N-tolerant maize cultivar to maintain higher photosynthesis and yield under low-N,low-light,and combined stress.In a three-year field trial of low-N-tolerant and low-N-sensitive maize cultivars under two N fertilization(normal N:240 kg N ha^(−1);low-N:150 kg N ha^(−1))and two light conditions(normal light;low-light:35%light reduction),the tolerant cultivar showed higher net photosynthetic rate than the sensitive one.Random Forest analysis and Structural Equation Modeling identified PSI donor-side limitation(elevated Y_(ND))as the key photosynthetic constraint.The tolerant cultivar maintained higher D1 and PsaA protein levels and preferentially allocated photosynthetic N to electron transport.This strategy reduced Y_(ND)and sustained photosystem stability,thus improving carboxylation efficiency and resulting in higher photosynthesis.展开更多
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act...Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.展开更多
基金supported by the National Natural Science Foundation of China(No.32571336 and 32271048)Research Funds of Centre for Leading Medicine and Advanced Technologies of IHM(No.2025IHM01100)。
文摘Chronic migraine(CM)is a prevalent and highly debilitating neurological disorder.Functional magnetic resonance imaging(fMRI)studies have demonstrated associations between abnormal brain region activation and CM,yet the underlying complex neural circuitry mechanisms remain unclear.The spinal trigeminal nucleus caudalis(Sp5C)serves as the primary central hub for orofacial nociceptive input,receiving trigeminal pain signals and projecting to higher-order centers such as the thalamus.Therefore,we sought to investigate whether the Sp5C region and its associated circuits were involved in CM pathogenesis.In this study,we established a CM mouse model through repeated intraperitoneal injections of nitroglycerin(NTG).Using a combination of in vivo fiber photometry and in vitro c-Fos immunohistochemistry,we found a marked periorbital and plantar mechanical allodynia in CM mice,accompanied by increased glutamatergic neuronal activity in Sp5C.Chemogenetic manipulation of Sp5C glutamatergic neurons(Sp5CV^(glut2))bidirectionally modulated migraine-like behaviors and induced pain-related affective states,as evidenced by conditioned place preference/aversion(CPP/CPA)paradigms.Anterograde viral tracing revealed dense projections from Sp5C^(Vglut2)to the subthalamic nucleus(STN),which was activated in CM mice.Optogenetic activation of the Sp5C-STN pathway similarly produced migraine-like behaviors and pain-related aversive memory in mice.Altogether,we revealed a critical role of the Sp5CVglut2-STN circuit in the development and modulation of CM.Our findings provide novel mechanistic insights into the central mechanisms underlying CM,establishing potential theoretical foundations for clinical diagnosis and therapeutic development.
基金supported by the National Key Research and Development Program of China(2022YFD190160304 and 2018YFD0301206)Natural Science Foundation of Sichuan Province(2022NSFSC0013)Sichuan Provincial Maize Innovation Team Construction Project(SCCXTD-2023-02).
文摘A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.
基金supported by the Key Program of Natural Science Foundation of Sichuan Province(2022NSFSC0013)National Key Research and Development Program of China(2022YFD1901603,2023YFD2301902).
文摘This study aimed to identify the physiological mechanisms enabling low-N-tolerant maize cultivar to maintain higher photosynthesis and yield under low-N,low-light,and combined stress.In a three-year field trial of low-N-tolerant and low-N-sensitive maize cultivars under two N fertilization(normal N:240 kg N ha^(−1);low-N:150 kg N ha^(−1))and two light conditions(normal light;low-light:35%light reduction),the tolerant cultivar showed higher net photosynthetic rate than the sensitive one.Random Forest analysis and Structural Equation Modeling identified PSI donor-side limitation(elevated Y_(ND))as the key photosynthetic constraint.The tolerant cultivar maintained higher D1 and PsaA protein levels and preferentially allocated photosynthetic N to electron transport.This strategy reduced Y_(ND)and sustained photosystem stability,thus improving carboxylation efficiency and resulting in higher photosynthesis.
基金financially supported by the National Key Research and Development Program of China(2022YFD190160304)Natural Science Foundation of Sichuan Province(2022NSFSC0013)+1 种基金Sichuan Maize Innovation Team Construction Project(SCCXTD-2022-02)National Key Research and Development Program of China(2018YFD0301206)。
文摘Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.
