Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain-derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor (BDNF) is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal (HPA) axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield (CA3) and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages (2 months and 15 months) were randomly assigned to six groups: two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field (OF) test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals (age: F=6.173, P <0.05, stress: F=6.056, P <0.05). Stress was the main factor affecting sucrose preference (F=123.608, P <0.05). Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals (P <0.05). The older stress rats showed a lower sucrose preference than young stress rats (P <0.05). Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square (P <0.05), exhibiting fewer vertical movements (P <0.05) and less grooming (P <0.05). Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups (P <0.05), a reduction that was still present at the eighth day after stress (P <0.05). Stress and age were the main factors affecting the expression of BDNF (F=9.408, P <0.05; F=106.303, P <0.05). The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

Effects of unpredictable chronic stress on behavior and brain- derived neurotrophic factor expression in CA3 subfield and dentate gyrus of the hippocampus in different aged rats

Background Brain-derived neurotrophic factor （BDNF） is a stress-responsive intercellular messenger modifying hypothalamic-pituitary-adrenal （HPA） axis activity. The interaction between stress and age in BDNF expression is currently not fully understood. This study was conducted to observe unpredictable stress effect on behavior and BDNF expression in CA3 subfield （CA3） and dentate gyrus of hippocampus in different aged rats. Methods Forty-eight Wistar rats of two different ages （2 months and 15 months） were randomly assigned to six groups： two control groups and four stress groups. The rats in the stress group received three weeks of unpredictable mild stress. The depression state and the stress level of the animals were determined by sucrose preference test and observation of exploratory behavior in an open field （OF） test. The expressions of BDNF in CA3 and dentate gyrus of the hippocampus were measured using immunohistochemistry. Results Age and stress had different effects on the behavior of different aged animals （age： F=6.173, P〈0.05, stress： F=6.056, P 〈0.05）. Stress was the main factor affecting sucrose preference （F=123.608, P 〈0.05）. Decreased sucrose preference and suppressed behavior emerged directly following stress, lasting to at least the eighth day after stress in young animals （P 〈0.05）. The older stress rats showed a lower sucrose preference than young stress rats （P 〈0.05）. Older control rats behaved differently from the younger control animals in the OF test, spending more time in the central square （P 〈0.05）, exhibiting fewer vertical movements （P 〈0.05） and less grooming （P 〈0.05）. Following exposure to stress, older-aged rats showed no obvious changes in vertical movement and grooming. This indicates that aged rats were in an unexcited state before the stress period, and responded less to stressful stimuli than younger rats. There was significantly lower BDNF expression in the CA3 and dentate gyrus regions of the hippocampus following stress in both age groups （P〈0.05）, a reduction that was still present at the eighth day after stress （P〈0.05）. Stress and age were the main factors affecting the expression of BDNF （F=9.408, P 〈0.05; F=106.303, P 〈0.05）. The aged stress group showed lower BDNF expression compared to the young stressed group at every testing time point. Conclusion Stress has age-dependent effects on behavioral responses and hippocampal BDNF expression in rats.     

白松片对抑郁模型大鼠海马脑源性神经营养因子和酪氨酸激酶B表达的影响

目的采用慢性应激复制抑郁大鼠模型,观测白松片对抑郁模型大鼠海马BDNF、TrkB表达的影响,探讨白松片的抗抑郁作用机制。方法将大鼠随机分为正常组、模型组、白松片组、氟西汀组,采用连续21d慢性轻度不可预见性应激配合孤养复制抑郁模型。运用免疫组化方法研究白松片对抑郁模型大鼠海马CA1、CA3区锥体细胞和齿状回颗粒细胞BDNF、TrkB蛋白表达的影响。结果与正常组相比,模型组大鼠海马CA1、CA3区和齿状回BDNF、TrkB免疫反应阳性神经元平均灰度值上升,分别为107. 73±3. 43、119. 40±6. 36、109. 20±4. 65;与模型组相比,白松片组大鼠海马CA1、CA3区和齿状回BDNF、TrkB免疫反应阳性神经元平均灰度值下降,分别为105. 80±3. 32、109. 87±4. 82、105. 00±2. 56。结论白松片增加抑郁模型大鼠海马BDNF、TrkB的表达,可能是其抗抑郁作用的分子机制之一。     

跑台运动对脑卒中后抑郁大鼠抑郁样行为、海马氧化应激及海马CA1区BDNF表达的影响

目的 观察脑卒中慢性应激大鼠抑郁样行为、海马氧化应激及海马CA1区脑源性神经营养因子(BDNF)表达的变化和中等强度跑台运动的干预作用,探讨跑台运动影响卒中后抑郁(PSD)大鼠抑郁行为的可能机制.方法 将44只大鼠随机分为4组:即假手术组(sham)、卒中组(MCAO)、卒中抑郁组(PSD)及PSD运动组(PSD+E)...     

慢性应激大鼠脑源性营养因子的表达分析

目的 探讨慢性不可预知轻度应激(CUMS)大鼠模型各脑区脑源性神经营养因子(BDNF)的表达及抗抑郁药对BDNF表达的影响.方法 将24只雄性SD大鼠随机分为三组(n=8):A组为对照组;B组为CUMS应激组;C组为CUMS应激+西太普兰用药组(每天腹腔注射西酞普兰水溶液2 mL,10 mg/kg).实验为期6周,每周称量大鼠体质量,每3周测试大鼠的糖水偏爱度,造模前及造模6周末通过旷场试验评价大鼠行为.6周后处死大鼠获取脑组织,采用Real-Time PCR检测各脑区BDNFmRNA表达水平.结果 第6周末,B组大鼠的糖水偏爱度明显低于A、C两组(P＜0.05)且行为增多.应激实验开始后,B、C两组大鼠体质量均明显低于A组(P＜0.05).B组BDNF mRNA在海马中的表达高于A组,但差异无统计学意义(P=0.07);C组纹状体中BDNF mRNA表达明显低于A组(P＜0.05).结论 慢性应激可能引起海马BDNF表达升高,抗抑郁药物可能导致纹状体BDNF表达降低.     

慢性染铅大鼠海马脑源性神经营养因子的改变

Objective: To investigate the changes of brain derived neurotrophic factor(BDNF) in hippocampus of chronic lead exposed rats. Methods: Wistar rats were exposed to lead by drinking 0.02%、0.2% lead acetate solution for three months, respectively. Investigate the changes of learning and memory ability by Y-labyrinth experiment, study the changes of BDNF positive neuron in CA1, CA3 and dentate gyrus in hippocampus of rats by immunohistochemistry. Results: BDNF positive neurons distribute everywhere in the hippocampus under normal condition. Compared with the contral group, the number of BDNF positive neurons in the hippocampus subregions were decreased significantly of two different dosage (0.02%, 0.2% ) chronic lead exposed groups( P ＜ 0. 05). Conclusion: These results suggest that the reduction of BDNF positive neuron in hippocampus might be related to the impact of lead on learning and memory.     

红藻氨酸诱导大鼠癫痫发作时海马mGluR5 mRNA表达变化的动态观察

目的 探讨红藻氨酸（KA,10mg.kg^-1)诱导大鼠癫痫发作时海马代谢型谷氨酸受体5亚型（mGluR5)mRNA表达变化的病理特征。方法 采用同位素S^35 dATP标记寡核苷酸探针原位杂交法检测大鼠癫痫发作前后海马mGluR5mRNA的表达变化。通过图像分析系统进行定量处理。同时观察大鼠行为学及脑电变化。结果 KA注射后大鼠均出现严重边缘性惊厥,脑电图表现为阵发性癫痫样放电,正常大鼠海马中有丰富的mGluR5 mRNA表达,以齿状回和CA1区表达较高,KA注射后海马各区mGLuR5 mRNA表达呈时间依赖性下调,CA1,CA3,CA4区表达在2h呈现出显著性差异（P＜0．05）,齿状回区表达在1h即有显著性差异（P＜0．01）,至72h各区表达均至最低。结论 mGluR5在癫痫发作后表达下降可能有助于限制神经元网络的异常兴奋性,使细胞发挥自身保护性作用。     

大鼠脑局部缺血再灌流后c-fos mRNA及c-Fos蛋白的表达

线栓法复制大鼠大脑中动脉缺血再灌流动物模型 ,于缺血 1h后分别再灌流 1h及 2h。原位杂交及免疫组化染色显示 ,再灌流 1h及 2h ,缺血侧额叶及顶叶皮质、海马各区以及齿状回c fosmRNA及c Fos蛋白表达均有不同程度诱导 ,于再灌流前电针“百会”及“风府”2穴 3 0min ,c fosmRNA和c Fos蛋白的诱导于再灌流 1h及 2h在缺血侧额叶、顶叶皮质 (P <0 .0 0 1 )及齿状回 (P <0 .0 1 )均显著增加 ;海马各区c Fos蛋白表达于再灌流 2h亦有显著增加(CA1与CA4:P <0 .0 5 ;CA2与CA3 :P <0 .0 1 )。该区c fosmRNA表达增加仅见于再灌流 1h的CA1及CA4区 (P <0 .0 5 )。HE染色示缺血区的神经元变性亦减轻。结果表明 :再灌流前给予电针处理使c fosmRNA及其产物c Fos蛋白表达增加 ,可能与电针对脑缺血再灌流动物模型的脑保护作用有关     

慢性脑灌注不足老龄大鼠脑内BDNF的表达

目的探讨老龄大鼠慢性灌注不足后脑内脑源性神经营养因子(brain-derived neurotrophic,BDNF)的表达在血管性痴呆形成中的作用.方法采用Pulsinelli四血管阻断(4-vessel occlusion,4VO)改良法建立血管性痴呆大鼠模型,穿梭箱系统检测大鼠的学习记忆能力.应用免疫组化ABC法检测海马各区及额、颞叶皮层BDNF的表达.结果4VO 1周组海马CA1区BDNF阳性细胞数与对照组比较显著减少(P＜0.01),2周组、4周组仍进行性下降(P＜0.01),2月组与4周组无显著差异(P＞0.05).CAI区BDNF的表达与大鼠AAR成绩变化规律基本一致.3 d组额、颞叶皮层BDNF表达显著增加,1周组CA3、齿状回及颞叶皮层BDNF显著减少(P＜0.01),而后BDNF的表达无明显变化.结论慢性脑灌注不足老龄大鼠脑内BDNF表达的减少可能在血管性痴呆的形成中起重要作用.     

重组人促红细胞生成素对衰老大鼠脑组织不同部位BDNF表达的影响

目的 探讨重组人促红细胞生成素(rhEPO)对衰老大鼠脑组织内不同部位脑源性神经营养因子(BDNF)表达的影响.方法 40只2月龄雄性SD大鼠,随机分为4组:阴性对照组(N),D-半乳糖组(D),EPO干预组(E),阳性对照组(P),每组10只.应用免疫组化染色对比观察外源性rhEPO干预后D-半乳糖衰老大鼠脑组织不同部位BDNF表达的变化.结果 不同组大鼠比较发现相同部位BDNF表达存在显著差异:D组大鼠海马CA1、CA3、DG及额叶皮质区BDNF阳性细胞计数较N组相同部位明显减少(P<0.05),而应用rhEPO干预后的E组和P组大鼠海马CA1、CA3、DG及大脑皮质运动区BDNF阳性细胞计数较D组及N组相同部位显著增加(P<0.05);但E组和P组比较无差异.同组大鼠不同部位BDNF阳性细胞比较发现:同组大鼠不同部位BDNF阳性细胞个数存在显著不同(P<0.05),其中额叶皮质区阳性细胞数最多,其次是海马CA3区,海马DG区,海马CA1区.结论 rhEPO对增强大鼠神经细胞BDNF的表达具有普遍性,提示rhEPO可能能够通过增强内源性BDNF对神经系统衰老发挥保护作用.     

戊四氮点燃大鼠海马星形胶质细胞巢蛋白的表达

目的：观察戊四氮点燃大鼠海马各区巢蛋白(nestin)的表达,以探讨其与癫痫发病机制的关系。方法：将20只成年雄性SD大鼠随机分为实验组和对照组,实验组采用戊四氮点燃大鼠模型,观察大鼠痫性发作行为和脑电图表现,用免疫组织化学方法观察海马各区星形细胞活化标志巢蛋白表达的变化。结果：实验组大鼠于4周后均达到点燃状态,而对照组行为正常。2组脑电图背境电活动以a节律为主,实验组Ⅳ或Ⅴ级痫性发作时脑电图均出现典型的高波幅棘慢波、尖慢波。实验组海马各区nestin阳性星形细胞较对照组明显增多。结论：戊四氮点燃引起海马内nestin阳性星性细胞明显增加,提示癫痫脑组织内存在星形细胞增生和活化,这可能是癫痫脑组织胶质化及点燃维持的病理基础。     

乌灵胶囊增加慢性不可预见性温和应激大鼠海马连接蛋白43的表达改善神经再生（英文）

目的：探讨乌灵胶囊对慢性不可预见性温和应激（chronic unpredictable mild stress , CMS）抑郁模型大鼠海马齿状回脑源性神经营养因子（brain-derived neurotrophic factor , BDNF）、神经再生,以及连接蛋白43（connexin 43 ,Cx43）表达的影响。方法：45只成年雄性Sprague-Dawley大鼠随机分入对照组（n=15）、模型组（n=15）和乌灵胶囊组（n=15）。模型组和乌灵胶囊组大鼠接受连续3周的CMS,造模期间,乌灵胶囊按100 mg/（kg.d）加入乌灵胶囊组大鼠的膳食中,连续治疗21 d。采用糖水偏爱实验评价大鼠的抑郁程度。抑郁行为测试结束后,取双侧海马组织,用免疫组织化学法检测BDNF与5-溴脱氧尿苷（5-bromodeoxyuridine ,BrdU）的表达;用逆转录聚合酶链反应和蛋白印迹法检测海马中Cx43 mRNA与蛋白表达。结果：慢性应激大鼠齿状回BDNF阳性表达、新生细胞数及Cx43 mRNA和蛋白表达水平均较正常大鼠明显下降。乌灵胶囊治疗后,CMS大鼠抑郁行为得到改善,异常的海马神经再生恢复,Cx43 mRNA和蛋白表达变得正常,但BDNF表达无明显改变。结论：乌灵胶囊可增加CMS模型大鼠海马神经再生及改善抑郁症状,其机制可能与增加Cx43表达有关,与BDNF无关。