Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice ...Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.展开更多
Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal s...Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal stress alters the phenotype of offspring via immunological mechanisms and that immunological dysfunction, such as elevated interleukin-18 levels, has been reported in cultures of microglia. Prenatal restraint stress(PRS) in rats permits direct experimental investigation of the link between prenatal stress and adverse outcomes. However, the majority of studies have focused on the consequences of PRS delivered in the second half of pregnancy, while the effects of early prenatal stress have rarely been examined. Therefore, pregnant rats were subjected to PRS during early/middle and late gestation(days 8–14 and 15–21, respectively). PRS comprised restraint in a round plastic transparent cylinder under bright light(6500 lx) three times per day for 45 minutes. Differences in interleukin-18 expression in the hippocampus and in behavior were compared between offspring rats and control rats on postnatal day 75. We found that adult male offspring exposed to PRS during their late prenatal periods had higher levels of anxiety-related behavior and depression than control rats, and both male and female offspring exhibited higher levels of depression-related behavior, impaired recognition memory and diminished exploration of novel objects. Moreover, an elevated level of interleukin-18 was observed in the dorsal and ventral hippocampus of male and female early-and late-PRS offspring rats. The results indicate that PRS can cause anxiety and depression-related behaviors in adult offspring and affect the expression of interleukin-18 in the hippocampus. Thus, behavior and the molecular biology of the brain are affected by the timing of PRS exposure and the sex of the offspring. All experiments were approved by the Animal Experimentation Ethics Committee at Kunming Medical University, China(approval No. KMMU2019074) in January 2019.展开更多
Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the spec...Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear.Therefore,further investigation is necessary.Methods:We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis,social behavioural tests,hippocampal electrophysiology,immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR.Additionally,we utilized optogenetics and administered ursolic acid(UA)via oral gavage to examine the effects of these agents on social memory in mice.Results:The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1(vCA1)under both physiological conditions and AD-like tau pathology.As tau progressively accumulated,vCA1,especially its excitatory and parvalbumin(PV)neurons,were fully filled with mislocated and phosphorylated tau(p-Tau).This finding was not observed for dorsal hippocampal CA1(dCA1).The overexpression of human tau(hTau)in excitatory and PV neurons mimicked AD-like tau accumulation,significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1.Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory.Notably,1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB(TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory.Conclusion:This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation.Notably,our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.展开更多
BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nuc...BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE： To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 （Gi2） in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING： A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA （Shanghai, China） between September 2002 and March 2004. MATERIALS： Thirty-six, healthy, male, Sprague-Dawley （SD） rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory （China）; naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory （China）; and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc （USA）. METHODS： Thirty-six SD rats were randomly divided into six groups （n = 6）： （1） acute morphine-dependent group, （2） acute abstinent group, （3） acute control group, （4） chronic morphine-dependent group, （5） chronic abstinent group, and （6） chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine （5 mg/kg）, one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone （5 mg/kg）. Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20：00, which increased by 5 mg/kg at 8：00, 12：00, and 20：00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone （5 mg/kg） at 8：00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES： The concentration of Gi2 protein in the five brain regions （ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus） was detected by immunohistochemistry. RESULTS： In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group （P 〈 0.01）, while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus （P 〈 0.01 ） compared to the chronic control group. CONCLUSION： Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.展开更多
基金supported financially by the National Natural Science Foundation of China,No.82071272(to YZ).
文摘Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.
基金supported by the National Natural Science Foundation of China,No.81260296(to LJA)and 81300987(to QLi)
文摘Exposure to maternal stress during prenatal life is associated with an increased risk of neuropsychiatric disorders, such as depression and anxiety, in offspring. It has also been increasingly observed that prenatal stress alters the phenotype of offspring via immunological mechanisms and that immunological dysfunction, such as elevated interleukin-18 levels, has been reported in cultures of microglia. Prenatal restraint stress(PRS) in rats permits direct experimental investigation of the link between prenatal stress and adverse outcomes. However, the majority of studies have focused on the consequences of PRS delivered in the second half of pregnancy, while the effects of early prenatal stress have rarely been examined. Therefore, pregnant rats were subjected to PRS during early/middle and late gestation(days 8–14 and 15–21, respectively). PRS comprised restraint in a round plastic transparent cylinder under bright light(6500 lx) three times per day for 45 minutes. Differences in interleukin-18 expression in the hippocampus and in behavior were compared between offspring rats and control rats on postnatal day 75. We found that adult male offspring exposed to PRS during their late prenatal periods had higher levels of anxiety-related behavior and depression than control rats, and both male and female offspring exhibited higher levels of depression-related behavior, impaired recognition memory and diminished exploration of novel objects. Moreover, an elevated level of interleukin-18 was observed in the dorsal and ventral hippocampus of male and female early-and late-PRS offspring rats. The results indicate that PRS can cause anxiety and depression-related behaviors in adult offspring and affect the expression of interleukin-18 in the hippocampus. Thus, behavior and the molecular biology of the brain are affected by the timing of PRS exposure and the sex of the offspring. All experiments were approved by the Animal Experimentation Ethics Committee at Kunming Medical University, China(approval No. KMMU2019074) in January 2019.
基金supported in part by the National Natural Science Foundation of China(91949205,82071219,82001134,31730035,81721005,and 82201584)the Hubei Provincial Key S&T Program(2018ACA142)the Guangdong Provincial Key S&T Program(2018B030336001).
文摘Background:Episodic memory loss is a prominent clinical manifestation of Alzheimer’s disease(AD),which is closely related to tau pathology and hippocampal impairment.Due to the heterogeneity of brain neurons,the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear.Therefore,further investigation is necessary.Methods:We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis,social behavioural tests,hippocampal electrophysiology,immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR.Additionally,we utilized optogenetics and administered ursolic acid(UA)via oral gavage to examine the effects of these agents on social memory in mice.Results:The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1(vCA1)under both physiological conditions and AD-like tau pathology.As tau progressively accumulated,vCA1,especially its excitatory and parvalbumin(PV)neurons,were fully filled with mislocated and phosphorylated tau(p-Tau).This finding was not observed for dorsal hippocampal CA1(dCA1).The overexpression of human tau(hTau)in excitatory and PV neurons mimicked AD-like tau accumulation,significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1.Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory.Notably,1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB(TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory.Conclusion:This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation.Notably,our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.
文摘目的观察针刺对海洛因复吸大鼠脑神经细胞凋亡的影响。方法采用剂量递增法复制海洛因成瘾大鼠模型,将40只Wistar大鼠平均分成正常组、模型组、针刺组、药物组,于实验第39天取4组大鼠海马、中脑腹侧被盖区(ventral tegmental area,VTA)脑组织,光镜下观察神经细胞坏死情况,采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(terminal deoxynucleotidyl transferase mediated nick end labeling,TUNEL)检测脑神经细胞凋亡情况。结果光镜下可见模型组大鼠脑海马、VTA神经细胞丢失、变性较严重,核溶解消失,神经细胞变性坏死及间质水肿明显,并可见筛状软化灶。针刺组未见明显筛状软化灶,神经细胞变性坏死及间质水肿程度较模型组、药物组减轻。针刺组神经细胞间质水肿较轻,未见明显筛状软化灶,神经细胞水肿坏死变性较少量。与正常组比较,模型组大鼠脑海马、VTA中TUNEL染色阳性细胞数显著增多(P<0.01);与模型组、药物组比较,针刺组大鼠脑海马、VTA中TUNEL染色阳性细胞数显著减少(P<0.01)。结论海洛因成瘾可致大鼠脑神经细胞凋亡,针刺"百会"、"大椎"穴可抑制神经细胞凋亡。
文摘BACKGROUND： Drug addiction involves two main central nervous systems, namely the dopamine and noradrenaline systems. These systems are primarily distributed in five brain regions： the ventral tegmental area, the nucleus accumbens, the prefrontal cortex, the hippocampus, and the locus coeruleus. OBJECTIVE： To investigate regional changes of guanine nucleotide binding protein-inhabitant 2 （Gi2） in dopaminergic and noradrenergic neurons in brains of morphine-tolerant and -dependent rats. DESIGN, TIME, AND SETTING： A randomized control study was performed at the Department of Neurobiology in the Second Military Medical University of Chinese PLA （Shanghai, China） between September 2002 and March 2004. MATERIALS： Thirty-six, healthy, male, Sprague-Dawley （SD） rats were used to establish morphine-dependent models. Morphine hydrochloride was a product of Shenyang First Pharmaceutical Factory （China）; naloxone hydrochloride was a product of Beijing Four-Ring Pharmaceutical Factory （China）; and α subunit of Gi2 antibody was offered by Santa Cruz Biotechnology, lnc （USA）. METHODS： Thirty-six SD rats were randomly divided into six groups （n = 6）： （1） acute morphine-dependent group, （2） acute abstinent group, （3） acute control group, （4） chronic morphine-dependent group, （5） chronic abstinent group, and （6） chronic control group. Rats in the acute morphine-dependent and the acute groups were injected with morphine （5 mg/kg）, one injection every two hours, for a total of eight injections. In the acute and chronic morphine-dependent rat models, morphine withdrawal syndrome was precipitated by an injection of naloxone （5 mg/kg）. Rats in the acute control group were given a peritoneal injection of physiological saline at the same administration time as the above two groups. Rats in the chronic morphine-dependent and chronic abstinent groups were injected with morphine three times per day. The administration dose on day 1 was initially 5 mg/kg at 20：00, which increased by 5 mg/kg at 8：00, 12：00, and 20：00 until day 7. On day 13, the dose continuously increased by 10 mg/kg until a chronic morphine-dependent rat model was successfully induced. Afterwards, the rats presented with withdrawal syndromes on naloxone （5 mg/kg） at 8：00 on the same day. Rats in the chronic control group were injected with physiological saline at the same time of the two chronic groups. MAIN OUTCOME MEASURES： The concentration of Gi2 protein in the five brain regions （ventral tegmental area, nucleus accumbens, prefrontal cortex, locus coeruleus, and hippocampus） was detected by immunohistochemistry. RESULTS： In the acute morphine-dependent and acute abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, compared to the acute control group （P 〈 0.01）, while no obvious changes were detected in other brain regions. In the chronic morphine-dependent and chronic abstinent groups, Gi2 protein concentration was significantly decreased in the nucleus accumbens, but significantly increased in the locus coeruleus （P 〈 0.01 ） compared to the chronic control group. CONCLUSION： Morphine dependence and tolerance may induce obvious reductions of Gi2 protein levels in the nucleus accumbens of rats. Chronic morphine dependence desensitizes the homologous neurons.
