Background::Cerebrovascular disease (CVD) ranks among the foremost factors responsible for mortality on a global scale. The mortality patterns of CVDs and temporal trends in China need to be well-illustrated and updated.Methods::We collected mortality data on patients with CVD from Chinese Center for Disease Control and Prevention’s Disease Surveillance Points (CDC-DSP) system. The mortality of CVD in 2020 was described by age, sex, residence, and region. The temporal trend from 2013 to 2019 was evaluated using joinpoint regression, and estimated rates of decline were extrapolated until 2030 using time series models.Results::In 2019, the age-standardized mortality in China (ASMRC) per 100,000 individuals was 113.2. The ASMRC for males (137.7/10 5) and rural areas (123.0/10 5) were both higher when stratified by gender and urban/rural residence. The central region had the highest mortality (126.5/10 5), the western region had a slightly lower mortality (123.5/10 5), and the eastern region had the lowest mortality (97.3/10 5). The age-specific mortality showed an accelerated upward trend from aged 55-59 years, with maximum mortality observed in individuals over 85 years of age. The age-standardized mortality of CVD decreased by 2.43% (95% confidence interval, 1.02-3.81%) annually from 2013 to 2019. Notably, the age-specific mortality of CVD increased from 2013 to 2019 for the age group of over 85 years. In 2020, both the absolute number of CVD cases and the crude mortality of CVD have increased compared to their values in 2019. The estimated total deaths due to CVD were estimated to reach 2.3 million in 2025 and 2.4 million in 2030. Conclusion::The heightened focus on the burden of CVD among males, rural areas, the central and western of China, and individuals aged 75 years and above has emerged as a pivotal determinant in further decreasing mortalities, consequently presenting novel challenges to strategies for disease prevention and control.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To explore the impact of the sialic acid binding lectin-E(Siglec-E)on the inhibitory properties of parthenolide(PTL)against lipopolysaccharide(LPS)-induced M1 polarization of microglia(BV2).Methods ①Single cell sequencing data of Siglece related mouse brain tissue was obtained from Gene Expression Omnibus(GEO)database and divided into the WT group(n=3)and the Siglece-/-group(n=4).The microglia cells were screened,and the enrichment analysis was performed to analyze related differential genes and pathways.BV2 cells were constructed by the shRNA interference technique and were divided into NC-shRNA and Siglece-shRNA to detect the expression level of Siglec-E(Siglece).② NC-shRNA and Siglece-shRNA cells were respectively divided into the Control group,LPS group,PTL group and PTL+LPS group(n=3).The mRNA levels of markers of M1 polarization in microglia,iNOS,IL-1 β and IL-6,were detected by RT-qPCR.Siglecefl/fl and Cx3cr1cre mice were mated to obtain microglia-specific Siglece deletion(Siglecefl/fl×Cx3cr1cre)mice,and LPS-induced neuroinflammation model was established.③ Nine WT and Siglecefl/fl×Cx3cr1cre male mice were assigned to the Control group,LPS group and PTL+LPS group(n=3).RT-qPCR,immunofluorescence assay and Western blotting were used to verify the knock-out effect and polarization-related pathways,and to investigate the mechanism of Siglec-E affecting PTL inhibition of M1 polarization of microglia.Results Compared with the NC-shRNA group,the expression of Siglec-E in the Siglece-shRNA group was significantly decreased(P<0.01),indicating that the Siglec-E knock-down cell model was successfully established.With the stimulation of LPS,mRNA levels ofiNOS,IL-1 β and IL-6 were significantly up-regulated compared with the Control group both in shRNA cells and Siglece-shRNA cells(P<0.01).With the influence of PTL and LPS,the markers of M1 polarization in NC-shRNA cells mentioned before were significantly decreased(P<0.05),while for Siglice-shRNA cells,there were no significant changes in the markers of M1 polarization.PTL inhibited the phosphorylation of JNK and IκB protein(P<0.01)and the nuclear translocation of NF-κB in BV2 cells,down-regulated Siglec-E,and weakened the inhibitory effect.Compared with mice in the WT group,the expression of Siglec-E in microglia of Siglecefl/fl×Cx3cr1cre mice was decreased significantly(P<0.01),and the inhibitory effect of PTL on the phosphorylation of NF-κB in microglia of Siglecefl/fl×Cx3cr1cre mice was also decreased.Conclusion The absence of Siglec-E in microglia attenuates the inhibition of M1 polarization by the MAPK/NF-κB pathway targeted by PTL.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.

Objective To investigate the effects of pre-electroacupuncture(EA)on spatial learning and memory,the locus coeruleus-hippocampal neural circuit,and neuroinflammation in Alzheimer's disease(AD)-like rats,and to explore the possible mechanism of pre-EA in preventing and treating AD.Methods Thirty-six male SD rats were divided into the normal,model,EA,and sham EA groups using the random number table method,with nine rats per group.An AD-like rat model was prepared through intraperitoneal injection of 120 mg/(kg·d)D-galactose for eight consecutive weeks.After daily intraperitoneal injection,the rats in the EA group underwent EA stimulation at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints with a continuous wave,frequency of 50 Hz,and a current of 1 mA for 20 min once a day for 8 weeks.The sham EA group was only superficially punctured to the subcutaneous tissue at the"Neiguan"(PC6)and"Jianshi"(PC5)acupoints without electricity,and the rest of the operations were the same as those in the EA group.The Morris water maze experiment was then used to evaluate the spatial learning and memory of the rats.Immunofluorescence labeling was used to detect dopamine β hydroxylase and c-Fos co-localization in the locus coeruleus of noradrenergic neurons,as well as glial fibrillary acidic protein and tumor necrosis factor-α(TNF-α)co-localization in the CA1 area of the hippocampus of astrocytes.Western blotting was used to measure the protein expressions of norepinephrine(NE),β2-adrenergic receptor(β2AR),β-inhibitory protein 2(β-arrestin2),nuclear transcription factor-κB(NF-κB)inhibitory factor protein α(IκBα),and NF-κB in the hippocampus of rats.An enzyme-linked immunosorbent assay was used to detect the TNF-α,interleukin-1β(IL-1β),and interleukin-6(IL-6)contents in hippocampal tissue.Results Compared with the normal group,the average escape latency of the model group rats was prolonged,and the times of crossing platform and exploration time in the target quadrant were reduced(P<0.01),while the EA intervention can shorten the average escape latency and increase the times of crossing platform and exploration time in the target quadrant(P<0.01).Compared with the normal group,the expression of co-located noradrenergic neurons in the model group decreased,co-located astrocytes increased(P<0.01);NE,β2AR,β-arrestin2,and IκBα protein expression decreased(P<0.01),NF-κB protein expression increased(P<0.01);the contents of TNF-α,IL-1β,and IL-6 increased(P<0.01).Compared with the model group,the EA group showed an increase in the expression of co-located noradrenergic neurons,a decrease in co-located astrocytes(P<0.01),an increase in NE,β2AR,β-arrestin2,and IκBα protein expressions(P<0.01),a decrease in NF-κB protein expression(P<0.01),and a decrease in TNF-α,IL-1β,and IL-6 levels(P<0.01).No significant difference was observed in the above indicators between the model and sham EA groups.Conclusion Pre-EA at"Neiguan"(PC6)and"Jianshi"(PC5)can alleviate learning and memory dysfunction,alleviate noradrenergic neuronal loss in the locus coeruleus,inhibit astrocyte activation,protect the locus coeruleus-hippocampal neural circuit,and may be associated with inhibiting β2AR/β-arrestin2/NF-κB inflammatory pathway activation.