Background Obstructive sleep apnea （OSA） can cause cognitive dysfunction and may be a reversible cause of cognitive loss in patients with Alzheimer＇s disease （AD）. Chronic exposure to intermittent hypoxia （IH）,...Background Obstructive sleep apnea （OSA） can cause cognitive dysfunction and may be a reversible cause of cognitive loss in patients with Alzheimer＇s disease （AD）. Chronic exposure to intermittent hypoxia （IH）, such as encountered in OSA, is marked by neurodegenerative changes in rat brain. We investigated the change of thioredoxin （Trx）, spatial learning and memory in rats exposed to chronic intermittent hypoxia （CIH）. Methods Forty healthy male Sprague-Dawley （SD） rats were randomly divided into four groups of ten each： a CIH＋normal saline （CIH＋NS group）, a N-acetylcystein-treated CIH （CIH＋NAC） group, a sham CIH group （sham CIH＋NS）, and a sham NAC-treated sham CIH （CIH＋NAC） group. Spatial learning and memory in each group was assessed with the Morris water maze. Real-time PCR and Western blotting were used to examine mRNA and protein expression of Trx in the hippocampus tissue. The terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling （TUNEL） method was used to detect the apoptotic cells of the hippocampus CA1 region. Results CIH-rats showed impaired spatial learning and memory in the Morris water maze, including longer mean latencies for the target platform, reduced numbers of passes over the previous target platform and a smaller percentage of time spent in the target quadrant. Trx mRNA and protein levels were significantly decreased in the CIH-hippocampus, meanwhile, an elevated apoptotic index revealed apoptosis of hippocampal neurons of rats exposed to CIH. The rats, which acted better in the Morris water maze, showed higher levels of the Trx mRNA and protein in the hippocampus; apoptotic index of the neurons in the hippocampus of each group was negatively correlated with the Trx mRNA and protein levels. Conclusion The Trx deficit likely plays an important role in the impaired spatial learning and memory in the rats exposed to CIH and may work through the apoptosis of neurons in the hippocampus.展开更多
OBJECTIVE: To investigate the effects of electroacupuncture(EA) at the Guanyuan(CV 4) or Sanyinjiao(SP 6) acupoints on the hypothalamus-pituitary-ovary(HPO) axis and spatial learning and memory in female mice.METHODS:...OBJECTIVE: To investigate the effects of electroacupuncture(EA) at the Guanyuan(CV 4) or Sanyinjiao(SP 6) acupoints on the hypothalamus-pituitary-ovary(HPO) axis and spatial learning and memory in female mice.METHODS: Nine-month-old female mice with senescence-accelerated mouse prone 8(SAMP8)were divided into three groups: the disease model,EA-Guanyuan and EA-Sanyinjiao groups. Concurrently, 9-month old female mice with senescence-accelerated mouse resistance 1(SAMR1)were set as the control model group. The two treatment groups were given the same pattern of EA stimulation. Gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone(FSH) and Serum estradiol levels in the Hypothalamus-pituitary-ovary axis were assessed by enzyme-linked immunosorbent assay to determinethe HPO axis function level. Spatial learning and memory were assessed by the Morris Water Maze(MWM) test.RESULTS:(a) HPO axis: compared with the control model group, the disease model group displayed a decrease in E2 levels(P < 0.01), and an increase in Gn RH, LH and FSH levels(P < 0.01). E2 levels were increased in EA treatment groups compared with the disease model group(P < 0.05). In contrast,Gn RH and LH and FSH levels were reduced(P <0.05). EA-Sanyinjiao group was superior than EA-Guanyuan group on increasing E2 and declining Gn RH levels(P < 0.01).(b) The MWM test demonstrated that the response latency in the EA-Sanyinjiao treatment group declined from day 2 to day5 compared with the disease model group(P <0.05), whereas the EA-Guanyuan treatment group showed no significant difference.CONCLUSION: EA can regulate hormone(E2, FSH,LH, Gn RH) levels in the HPO axis and the spatial learning and memory ability in female SAMP8 mice. Moreover, this effect may have been more pronounced in the EA-Sanyinjiao group than the EA-Guanyuan group. The underlying mechanism of the EA-induced changes may be related to gonadal hormone shifts in the HPO axis, followed by an improvement in spatial learning and memory.展开更多
Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapopto...Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapoptosis when activated.Sprague-Dawley rats at postnatal day 7 were subcutaneously injected in the neck with ketamine 20 mg/kg,six times at 2-hour intervals.At 0,1,3,and 6 hours after final injection,western blot assay was used to detect the expression of cleaved caspase-3,p66ShcA,and phosphorylated p66ShcA.We found that the expression of activated p66ShcA and caspase-3 increased after ketamine exposure and peaked at 3 hours.The same procedure was performed on a different group of rats.At the age of 4 weeks,spatial learning and memory abilities were tested with the Morris water maze.Latency to find the hidden platform for these rats was longer than it was for control rats,although the residence time in the target quadrant was similar.These findings indicate that ketamine exposure resulted in p66ShcA being activated in the course of an apoptotic cascade during the neonatal period.This may have contributed to the deficit in spatial learning and memory that persisted into adulthood.The experimental protocol was approved by the Institutional Animal Care and Use Committee at the University of Texas at Arlington,USA (approval No.A13.008) on January 22,2013.展开更多
Objective To examine the effect of docosahexaenoic acid （DHA） deficiency in brain on spatial learning and memory in rats. Methods Sprague Dawley rats were fed with an n-3 fatty acid deficient diet for two generation...Objective To examine the effect of docosahexaenoic acid （DHA） deficiency in brain on spatial learning and memory in rats. Methods Sprague Dawley rats were fed with an n-3 fatty acid deficient diet for two generations to induce DHA depletion in brain, DHA in seven brain regions was analyzed using the gas-liquid chromatography. Morris water maze （MWM） was employed as an assessing index of spatial learning and memory in the n-3 fatty acid deficient adult rats of second generation. Results Feeding an n-3 deficient diet for two generations depleted DHA differently by 39%-63% in the seven brain regions including cerebellum, medulla, hypothalamus, striatum, hippocampus, cortex and midbrain, The MWM test showed that the n-3 deficient rats took a longer time and swam a longer distance to find the escape platform than the n-3 Adq group. Condusion The spatial learning and memory in adult rats are partially impaired by brain DHA depletion.展开更多
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 81070067）.
文摘Background Obstructive sleep apnea （OSA） can cause cognitive dysfunction and may be a reversible cause of cognitive loss in patients with Alzheimer＇s disease （AD）. Chronic exposure to intermittent hypoxia （IH）, such as encountered in OSA, is marked by neurodegenerative changes in rat brain. We investigated the change of thioredoxin （Trx）, spatial learning and memory in rats exposed to chronic intermittent hypoxia （CIH）. Methods Forty healthy male Sprague-Dawley （SD） rats were randomly divided into four groups of ten each： a CIH＋normal saline （CIH＋NS group）, a N-acetylcystein-treated CIH （CIH＋NAC） group, a sham CIH group （sham CIH＋NS）, and a sham NAC-treated sham CIH （CIH＋NAC） group. Spatial learning and memory in each group was assessed with the Morris water maze. Real-time PCR and Western blotting were used to examine mRNA and protein expression of Trx in the hippocampus tissue. The terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling （TUNEL） method was used to detect the apoptotic cells of the hippocampus CA1 region. Results CIH-rats showed impaired spatial learning and memory in the Morris water maze, including longer mean latencies for the target platform, reduced numbers of passes over the previous target platform and a smaller percentage of time spent in the target quadrant. Trx mRNA and protein levels were significantly decreased in the CIH-hippocampus, meanwhile, an elevated apoptotic index revealed apoptosis of hippocampal neurons of rats exposed to CIH. The rats, which acted better in the Morris water maze, showed higher levels of the Trx mRNA and protein in the hippocampus; apoptotic index of the neurons in the hippocampus of each group was negatively correlated with the Trx mRNA and protein levels. Conclusion The Trx deficit likely plays an important role in the impaired spatial learning and memory in the rats exposed to CIH and may work through the apoptosis of neurons in the hippocampus.
基金Supported by the National Natural Science Foundation of China(30973686)Medicinal Science and Techology Research Project(BWS11J052)+3 种基金the National key scientific instrument and equipment development project(2012YQ0401400901)the National Science and Techology Major Project(2012ZX09J12201)the National Key Technology R&D Program of China(2009BAK59B01)the Foundation of State Key Laboratory of Space Medicine Fundamentals and Application,China Astronaut Research and Training Center(SMFA10B01,SMFA12B05)
基金the National Science Foundation of China(the Experimental Research on Acupuncture for Prevention and Treatment Alzheimer's Disease Based on the Adjustment Imbalances of NIM,No.81072768)
文摘OBJECTIVE: To investigate the effects of electroacupuncture(EA) at the Guanyuan(CV 4) or Sanyinjiao(SP 6) acupoints on the hypothalamus-pituitary-ovary(HPO) axis and spatial learning and memory in female mice.METHODS: Nine-month-old female mice with senescence-accelerated mouse prone 8(SAMP8)were divided into three groups: the disease model,EA-Guanyuan and EA-Sanyinjiao groups. Concurrently, 9-month old female mice with senescence-accelerated mouse resistance 1(SAMR1)were set as the control model group. The two treatment groups were given the same pattern of EA stimulation. Gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone(FSH) and Serum estradiol levels in the Hypothalamus-pituitary-ovary axis were assessed by enzyme-linked immunosorbent assay to determinethe HPO axis function level. Spatial learning and memory were assessed by the Morris Water Maze(MWM) test.RESULTS:(a) HPO axis: compared with the control model group, the disease model group displayed a decrease in E2 levels(P < 0.01), and an increase in Gn RH, LH and FSH levels(P < 0.01). E2 levels were increased in EA treatment groups compared with the disease model group(P < 0.05). In contrast,Gn RH and LH and FSH levels were reduced(P <0.05). EA-Sanyinjiao group was superior than EA-Guanyuan group on increasing E2 and declining Gn RH levels(P < 0.01).(b) The MWM test demonstrated that the response latency in the EA-Sanyinjiao treatment group declined from day 2 to day5 compared with the disease model group(P <0.05), whereas the EA-Guanyuan treatment group showed no significant difference.CONCLUSION: EA can regulate hormone(E2, FSH,LH, Gn RH) levels in the HPO axis and the spatial learning and memory ability in female SAMP8 mice. Moreover, this effect may have been more pronounced in the EA-Sanyinjiao group than the EA-Guanyuan group. The underlying mechanism of the EA-induced changes may be related to gonadal hormone shifts in the HPO axis, followed by an improvement in spatial learning and memory.
基金supported by the National Natural Science Foundation of China,No.81200851(to DL)the National Institutes of Health of the USA,No.NS 040723(to QL)
文摘Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapoptosis when activated.Sprague-Dawley rats at postnatal day 7 were subcutaneously injected in the neck with ketamine 20 mg/kg,six times at 2-hour intervals.At 0,1,3,and 6 hours after final injection,western blot assay was used to detect the expression of cleaved caspase-3,p66ShcA,and phosphorylated p66ShcA.We found that the expression of activated p66ShcA and caspase-3 increased after ketamine exposure and peaked at 3 hours.The same procedure was performed on a different group of rats.At the age of 4 weeks,spatial learning and memory abilities were tested with the Morris water maze.Latency to find the hidden platform for these rats was longer than it was for control rats,although the residence time in the target quadrant was similar.These findings indicate that ketamine exposure resulted in p66ShcA being activated in the course of an apoptotic cascade during the neonatal period.This may have contributed to the deficit in spatial learning and memory that persisted into adulthood.The experimental protocol was approved by the Institutional Animal Care and Use Committee at the University of Texas at Arlington,USA (approval No.A13.008) on January 22,2013.
文摘Objective To examine the effect of docosahexaenoic acid （DHA） deficiency in brain on spatial learning and memory in rats. Methods Sprague Dawley rats were fed with an n-3 fatty acid deficient diet for two generations to induce DHA depletion in brain, DHA in seven brain regions was analyzed using the gas-liquid chromatography. Morris water maze （MWM） was employed as an assessing index of spatial learning and memory in the n-3 fatty acid deficient adult rats of second generation. Results Feeding an n-3 deficient diet for two generations depleted DHA differently by 39%-63% in the seven brain regions including cerebellum, medulla, hypothalamus, striatum, hippocampus, cortex and midbrain, The MWM test showed that the n-3 deficient rats took a longer time and swam a longer distance to find the escape platform than the n-3 Adq group. Condusion The spatial learning and memory in adult rats are partially impaired by brain DHA depletion.
基金This work was supported by the Ministry of Science and Technology of China(No.2006CB500807)the Program for Changjiang Scholars and Innovative Research Team in University from Ministry of Education of China the National Natural Science Foundation of China(No.30225023,30430240,30611120530).
