BACKGROUND:To investigate the mechanism underlying the basal forebrain-DMN/solv cholinergic projection-induced attenuation of brain injury after cardiopulmonary resuscitation(CPR).METHODS:Forty-six male Sprague-Dawley...BACKGROUND:To investigate the mechanism underlying the basal forebrain-DMN/solv cholinergic projection-induced attenuation of brain injury after cardiopulmonary resuscitation(CPR).METHODS:Forty-six male Sprague-Dawley rats were randomly divided into five groups:the sham group(n=6),the return of spontaneous circulation(ROSC) group(n=10),the optogenetic activation(CHAT-Light-CHR2) group(n=10),the optogenetic inhibition(CHAT-Light-NpHR) group(n=10),and the optogenetic activation combined with left cervical vagotomy(CHAT-Light-CHR2 + Lc VGX) group(n=10).Excitatory(CHR2) or inhibitory(NpHR) optogenetic viruses were injected into the basal forebrain(BF) of rats,followed by the implantation of ceramic ferrules.After three weeks of viral expression,the sham group received tracheotomy and catheterization only,the ROSC group underwent tracheotomy,asphyxial cardiac arrest,and CPR,and the CHR2 and NpHR groups received post-ROSC optogenetic activation or inhibition,respectively.The CHAT-Light-CHR2 + LcVGX group was pretreated with left cervical vagotomy followed by post-ROSC activation.Post-ROSC assessments included neurofunctional deficit score(NDS),histopathology(HE/Nissl/TUNEL staining and CD11b microglial activation) in the hippocampal CA1/prefrontal cortex,serum cytokines(IL-1β,IL-6 and TNF-α),and whole-brain immunofluorescence(c-Fos/CHAT) for neuronal activation mapping.RESULTS:Compared with the rats of sham group,rats of the ROSC group presented reduced NDS,neuronal loss,increased apoptosis,elevated CD11b expression,and increased cytokine levels.CHAT-CHR2 activation improved NDS,reduced neuronal loss and apoptosis,and decreased CD11b expression and TNF-α levels.CHAT-NpHR inhibition caused no improvement in NDS but exacerbated neuronal loss and CD11b expression elevation.CHAT-CHR2+LcVGX reversed these protective effects.Whole-brain immunofluorescence staining revealed that optogenetic activation of cholinergic neurons in the BF of the CHAT-Light-CHR2 group excited neurons in the DMN/solv region,which were identified as dopaminergic neurons.CONCLUSION:Cholinergic projections from the basal forebrain-DMN/solv may alleviate systemic and neuroinflammatory responses through the cholinergic anti-inflammatory pathway and mitigate brain injury following CPR.展开更多
基金supported by grants from the Medical and Health Research Project of Zhejiang Province (No.2023KY1167)the Key Discipline Group of Trauma Treatment in Huzhou City (No.XKQ-HT-202103C)Young Talent Program of Huzhou Central Hospital (No.2020YC15)。
文摘BACKGROUND:To investigate the mechanism underlying the basal forebrain-DMN/solv cholinergic projection-induced attenuation of brain injury after cardiopulmonary resuscitation(CPR).METHODS:Forty-six male Sprague-Dawley rats were randomly divided into five groups:the sham group(n=6),the return of spontaneous circulation(ROSC) group(n=10),the optogenetic activation(CHAT-Light-CHR2) group(n=10),the optogenetic inhibition(CHAT-Light-NpHR) group(n=10),and the optogenetic activation combined with left cervical vagotomy(CHAT-Light-CHR2 + Lc VGX) group(n=10).Excitatory(CHR2) or inhibitory(NpHR) optogenetic viruses were injected into the basal forebrain(BF) of rats,followed by the implantation of ceramic ferrules.After three weeks of viral expression,the sham group received tracheotomy and catheterization only,the ROSC group underwent tracheotomy,asphyxial cardiac arrest,and CPR,and the CHR2 and NpHR groups received post-ROSC optogenetic activation or inhibition,respectively.The CHAT-Light-CHR2 + LcVGX group was pretreated with left cervical vagotomy followed by post-ROSC activation.Post-ROSC assessments included neurofunctional deficit score(NDS),histopathology(HE/Nissl/TUNEL staining and CD11b microglial activation) in the hippocampal CA1/prefrontal cortex,serum cytokines(IL-1β,IL-6 and TNF-α),and whole-brain immunofluorescence(c-Fos/CHAT) for neuronal activation mapping.RESULTS:Compared with the rats of sham group,rats of the ROSC group presented reduced NDS,neuronal loss,increased apoptosis,elevated CD11b expression,and increased cytokine levels.CHAT-CHR2 activation improved NDS,reduced neuronal loss and apoptosis,and decreased CD11b expression and TNF-α levels.CHAT-NpHR inhibition caused no improvement in NDS but exacerbated neuronal loss and CD11b expression elevation.CHAT-CHR2+LcVGX reversed these protective effects.Whole-brain immunofluorescence staining revealed that optogenetic activation of cholinergic neurons in the BF of the CHAT-Light-CHR2 group excited neurons in the DMN/solv region,which were identified as dopaminergic neurons.CONCLUSION:Cholinergic projections from the basal forebrain-DMN/solv may alleviate systemic and neuroinflammatory responses through the cholinergic anti-inflammatory pathway and mitigate brain injury following CPR.
