Melatonin is a hormone synthesized and released primarily by the pineal gland. Its secretion fol-lows a circadian rhythm with a peak overnight. Its secretion is initiated approximately to the three months of age and c...Melatonin is a hormone synthesized and released primarily by the pineal gland. Its secretion fol-lows a circadian rhythm with a peak overnight. Its secretion is initiated approximately to the three months of age and continues to rise during the childhood. Previous to the puberty there is a de-crease of melatonin secretion that continues until the old age. Melatonin has effects in the body and acts through at least four mechanisms: membrane receptors, orphan nuclear receptors, calmodulin and free radicals. It has been suggested that aging can be a consequence of the oxidation of cells that eventually become vulnerable to injury and die. This work reviews the antioxidant effects of melatonin in a rodent model, on the formation of free radicals, on the MAP2 protein expression and on the electrophysiology of the hippocampus at different ages. The results indicate that melatonin maintains in a “best” state to the experimental animals compared to controls. It suggests the use of melatonin as a therapy to prevent or delay the aging effects on the cells.展开更多
Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial pro...Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial proteins in hippocampal cell apoptosis after transient cerebral ischemia-reperfusion injury in aged rats using a comparative proteomics strategy. Our exper-imental results show that the aged rat brain is sensitive to ischemia-reperfusion injury and that transient ischemia led to cell apoptosis in the hippocampus and changes in memory and cognition of aged rats. Differential proteomics analysis suggested that this phenomenon may be mediated by mitochondrial proteins associated with energy metabolism and apoptosis in aged rats. This study provides potential drug targets for the treatment of transient cerebral isch-emia-reperfusion injury.展开更多
Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clin...Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clinical symptoms and delay the progression of Alzheimer＇s disease. The present study replicated a rat model of aging induced by injecting quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of eleutheroside B or E （50, 100, 200 mg/kg）, and rats injected with Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose eleutheroside B or E. Hematoxylin-eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced cholinesterase activity, and dose-dependent increases in acetylcholine content and decreases in choline content following eleutheroside B or E treatment, similar to those seen in the Huperzine A group. These findings indicate that eleutheroside B or E improves learning and memory in aged rats. These effects of eleutheroside B or E may be mediated by activation of cholinesterase or enhanced reuse of choline to accelerate the synthesis of acetylcholine in hippocampal neurons.展开更多
Melatonin, the pineal indole is characterized by being a compound that crosses all cell membranes and which has been attributed to several mechanisms of action. Among these it is the ability to reduce free radicals, t...Melatonin, the pineal indole is characterized by being a compound that crosses all cell membranes and which has been attributed to several mechanisms of action. Among these it is the ability to reduce free radicals, thereby reducing the potential aging and cell death. Studies in different age Wistar rats have shown that chronic application of melatonin, in the hippocampus, reduces the concentration of free radicals and keeps its architecture. This study showed that melatonin increases the firing rate and favors the presence of bursting activity in animals of different ages. It is suggested that melatonin conserved hippocampal cells in good anatomical and physiological condition probably as a result of the elimination of free radicals.展开更多
The changes in density of M-cholinergic receptors in different areas of senile rats and the regulatory action of Huang Qi (黄芪Radix Astragali, a drug for warming yang and replenishing qi) were observed by autoradiogr...The changes in density of M-cholinergic receptors in different areas of senile rats and the regulatory action of Huang Qi (黄芪Radix Astragali, a drug for warming yang and replenishing qi) were observed by autoradiography. The results showed that the gray scale displayed in brain sections was clear and mainly distributed in the cortex, hippocampus and striate body, while that due to nonspecific combination was negligible. The gray scale in the cortex, hippocampus and striate body of the experimental group was markedly lower than that in the young control rats, decreased respectively by 24.87%, 14.12% and 12.76% (all P<0.05); but it was obviously higher than those in the senile control rats, increased respectively by 24.15%, 14.38% and 13.47% (P<0.05). The data indicate that Huang Qi (黄芪Radix Astragali) may up-regulate the decreased density of M-cholinergic receptors in the brain of senile rats.展开更多
目的:探讨长期有氧运动干预对脑衰老过程中大鼠学习记忆能力以及海马脑源性神经营养因子(BDNF)表达的影响。方法:将30只3月龄SD雄性大鼠随机分成青年对照组(YC组)、衰老对照组(OC组)和衰老运动组(OS组)3组,每组10只。OC组和OS组腹腔注...目的:探讨长期有氧运动干预对脑衰老过程中大鼠学习记忆能力以及海马脑源性神经营养因子(BDNF)表达的影响。方法:将30只3月龄SD雄性大鼠随机分成青年对照组(YC组)、衰老对照组(OC组)和衰老运动组(OS组)3组,每组10只。OC组和OS组腹腔注射D-半乳糖100 mg/kg/d,持续6周,OS组同期每日进行1小时游泳运动。6周后用Morris水迷宫实验评估各组大鼠的学习与记忆能力;然后断头取大鼠海马,分别采用Real Time-PCR和Western Blot技术检测其BDNF m RNA和BDNF蛋白的表达水平;取大脑皮质,进行自由基指标检测。结果:在Morris水迷宫定位航行试验中,与YC组相比,OC组平均逃避潜伏期显著延长(P<0.01);与OC组相比,OS组平均逃避潜伏期缩短(P<0.01)。在空间探索实验中,OC组平均穿越平台区域次数显著性少于YC组与OS组(P<0.01,P<0.05)。OC组海马BNDF m RNA和BNDF蛋白表达水平均低于YC组(P<0.01,P<0.05),而OS组海马BNDF m RNA和BNDF蛋白表达水平高于OC组(P<0.01,P<0.05)。结论:衰老过程中进行有氧运动可延缓脑衰老引起的学习记忆能力下降。有氧运动可上调衰老过程中大鼠海马BDNF的表达,这可能是有氧运动延缓脑衰老、改善学习记忆能力的分子机制之一。展开更多
文摘Melatonin is a hormone synthesized and released primarily by the pineal gland. Its secretion fol-lows a circadian rhythm with a peak overnight. Its secretion is initiated approximately to the three months of age and continues to rise during the childhood. Previous to the puberty there is a de-crease of melatonin secretion that continues until the old age. Melatonin has effects in the body and acts through at least four mechanisms: membrane receptors, orphan nuclear receptors, calmodulin and free radicals. It has been suggested that aging can be a consequence of the oxidation of cells that eventually become vulnerable to injury and die. This work reviews the antioxidant effects of melatonin in a rodent model, on the formation of free radicals, on the MAP2 protein expression and on the electrophysiology of the hippocampus at different ages. The results indicate that melatonin maintains in a “best” state to the experimental animals compared to controls. It suggests the use of melatonin as a therapy to prevent or delay the aging effects on the cells.
基金supported by a grant from Ministry of Science and Technology of Qingdao City,No.10-3-4-7-8-JCH
文摘Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial proteins in hippocampal cell apoptosis after transient cerebral ischemia-reperfusion injury in aged rats using a comparative proteomics strategy. Our exper-imental results show that the aged rat brain is sensitive to ischemia-reperfusion injury and that transient ischemia led to cell apoptosis in the hippocampus and changes in memory and cognition of aged rats. Differential proteomics analysis suggested that this phenomenon may be mediated by mitochondrial proteins associated with energy metabolism and apoptosis in aged rats. This study provides potential drug targets for the treatment of transient cerebral isch-emia-reperfusion injury.
基金supported by the Foundation from Department of Education of Hubei Province,No.D20111903
文摘Eleutheroside B or E, the main component of Acanthopanax, can relieve fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of acetylcholine significantly attenuate clinical symptoms and delay the progression of Alzheimer＇s disease. The present study replicated a rat model of aging induced by injecting quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of eleutheroside B or E （50, 100, 200 mg/kg）, and rats injected with Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose eleutheroside B or E. Hematoxylin-eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced cholinesterase activity, and dose-dependent increases in acetylcholine content and decreases in choline content following eleutheroside B or E treatment, similar to those seen in the Huperzine A group. These findings indicate that eleutheroside B or E improves learning and memory in aged rats. These effects of eleutheroside B or E may be mediated by activation of cholinesterase or enhanced reuse of choline to accelerate the synthesis of acetylcholine in hippocampal neurons.
文摘Melatonin, the pineal indole is characterized by being a compound that crosses all cell membranes and which has been attributed to several mechanisms of action. Among these it is the ability to reduce free radicals, thereby reducing the potential aging and cell death. Studies in different age Wistar rats have shown that chronic application of melatonin, in the hippocampus, reduces the concentration of free radicals and keeps its architecture. This study showed that melatonin increases the firing rate and favors the presence of bursting activity in animals of different ages. It is suggested that melatonin conserved hippocampal cells in good anatomical and physiological condition probably as a result of the elimination of free radicals.
文摘The changes in density of M-cholinergic receptors in different areas of senile rats and the regulatory action of Huang Qi (黄芪Radix Astragali, a drug for warming yang and replenishing qi) were observed by autoradiography. The results showed that the gray scale displayed in brain sections was clear and mainly distributed in the cortex, hippocampus and striate body, while that due to nonspecific combination was negligible. The gray scale in the cortex, hippocampus and striate body of the experimental group was markedly lower than that in the young control rats, decreased respectively by 24.87%, 14.12% and 12.76% (all P<0.05); but it was obviously higher than those in the senile control rats, increased respectively by 24.15%, 14.38% and 13.47% (P<0.05). The data indicate that Huang Qi (黄芪Radix Astragali) may up-regulate the decreased density of M-cholinergic receptors in the brain of senile rats.
文摘目的:探讨长期有氧运动干预对脑衰老过程中大鼠学习记忆能力以及海马脑源性神经营养因子(BDNF)表达的影响。方法:将30只3月龄SD雄性大鼠随机分成青年对照组(YC组)、衰老对照组(OC组)和衰老运动组(OS组)3组,每组10只。OC组和OS组腹腔注射D-半乳糖100 mg/kg/d,持续6周,OS组同期每日进行1小时游泳运动。6周后用Morris水迷宫实验评估各组大鼠的学习与记忆能力;然后断头取大鼠海马,分别采用Real Time-PCR和Western Blot技术检测其BDNF m RNA和BDNF蛋白的表达水平;取大脑皮质,进行自由基指标检测。结果:在Morris水迷宫定位航行试验中,与YC组相比,OC组平均逃避潜伏期显著延长(P<0.01);与OC组相比,OS组平均逃避潜伏期缩短(P<0.01)。在空间探索实验中,OC组平均穿越平台区域次数显著性少于YC组与OS组(P<0.01,P<0.05)。OC组海马BNDF m RNA和BNDF蛋白表达水平均低于YC组(P<0.01,P<0.05),而OS组海马BNDF m RNA和BNDF蛋白表达水平高于OC组(P<0.01,P<0.05)。结论:衰老过程中进行有氧运动可延缓脑衰老引起的学习记忆能力下降。有氧运动可上调衰老过程中大鼠海马BDNF的表达,这可能是有氧运动延缓脑衰老、改善学习记忆能力的分子机制之一。
