对香豆酸对慢性束缚应激诱导小鼠抑郁样行为的作用

目的:探索对香豆酸(p-CA)对慢性束缚应激(CRS)诱导小鼠抑郁样行为的作用。方法:实验分两批进行,第一批小鼠随机分成对照组(Control),慢性束缚应激组(CRS)和慢性束缚应激+p-CA组(CRS+p-CA),每组8只,其中慢性束缚应激小鼠每天接受4 h的束缚应激,连续束缚21 d,而对照组小鼠留在笼中不被打扰。第22日小鼠腹腔注射溶媒(10%吐温80)或p-CA(100mg/kg),注射后1 h进行自发活动测试(LMA),注射后4 h进行强迫游泳测试(FST),注射后24 h进行悬尾测试。第二批小鼠随机分成慢性束缚应激组(CRS),慢性束缚应激+ANA-12(原肌球蛋白激酶B拮抗剂)组(CRS+ANA-12)和慢性束缚应激+p-CA组(CRS+p-CA)慢性束缚应激+p-CA+ANA-12组(CRS+p-CA+ANA-12),每组8只,4组小鼠每天接受4 h的束缚应激,连续束缚21d。第22日小鼠腹腔注射溶媒(10%吐温80)或p-CA(100 mg/kg),ANA-12(0.5 mg/kg)在p-CA注射前30 min给药。注射后1 h进行自发活动测试(LMA),注射后2 ...     

GDNF在慢性应激和老化致小鼠行为与认知损伤中的作用

目的:探讨慢性应激对不同月龄小鼠空间学习记忆功能的影响,以及小鼠前脑皮层和海马胶质细胞源性神经营养因子(GDNF)的作用。方法:采用多因素慢性应激动物模型,通过旷场试验和Morris水迷宫试验,检测不同月龄小鼠行为及空间学习记忆能力,并检测GDNF在小鼠脑海马和前脑皮层的表达。结果:与青年(2月龄)小鼠比较,老年(15月龄)小鼠的自发活动和探究行为明显减少,空间学习记忆能力明显降低(P<0.05,P<0.01),且海马CA3区、齿状回和前脑皮层GDNF表达明显下降(P<0.05,P<0.01);在慢性应激后,与对照组比较,青年和老年应激组小鼠的自发活动和探究行为显著减少,空间学习记忆能力显著降低(P<0.05,P<0.01),且小鼠前脑皮层和海马GDNF表达显著下降(P<0.05,P<0.01),老年应激小鼠变化更加显著。结论:脑的老化和慢性应激导致小鼠行为及空间学习记忆功能改变,可能与海马和前脑皮层神经元GDNF表达的变化密切相关。     

浅析BDNF改善痴呆老龄鼠记忆障碍CA1区GrayⅠ型突触结构相关参数的变化

目的探讨BDNF（Brain derived neurotrophic factor）改善痴呆老龄鼠记忆障碍的机制。方法利用Morris迷宫试验观察脑内微量注射BDNF对痴呆小鼠自发活动和记忆巩固过程的影响,应用透射电镜和形态计量学分析痴呆老龄鼠海马GrayⅠ型突触的突出结构参数的变化。结果BDNF使痴呆小鼠在新异环境中的自发活动和探究行为明显增多;并显著延长电击后24 h的步入潜伏期（STL）;BDNF使痴呆老龄鼠海马CA1区GrayⅠ型突触的体积密度、面积密度、比表面和面数密度较治疗前增大,突触平均面积增大;突出界面曲率、突出间隙宽度、突出后致密物质均较治疗前增大,而较正常对照组减小。结论突触结构的变化和突出数量的减少是痴呆发病的病理机制之一;BDNF能够促进突触重建,改善痴呆老龄鼠的学习记忆。     

产对香豆酸酿酒酵母菌株的构建及优化

对香豆酸(p-coumaric acid)作为苯丙素类物质、芪类物质及黄酮类物质的重要前体化合物,在生物医药、化妆品及食品工业中均有广泛的应用价值。以酿酒酵母作为底盘菌株,利用合成生物学原理构建一株高产对香豆酸的人工酵母细胞。通过对比不同拷贝数的酪氨酸解氨酶(tyrosine ammonia lyase)合成的对香豆酸产量,发现随着基因拷贝数的增加对香豆酸的产量也相应提高;同时对酪氨酸的负反馈调控相关的蛋白质进行氨基酸定点突变得到Aro4pK229L和Aro7pG141S,利用delta位点将突变后的基因整合至酵母基因组,并挑取24株构建成功的酵母细胞进行发酵验证,发现菌株最高产量与最低产量相差28.87mg/L;为了进一步增加对香豆酸的代谢通量,对生成芳香醇类物质的旁路基因ARO10和PDC5进行敲除,发现同时敲除两个基因的菌株对香豆酸的产量最高,是敲除前产量的2.05倍(从42.71mg/L到87.56mg/L)。此外,通过设计前体酪氨酸的梯度添加实验,发现当添加1mmol/L的酪氨酸时,对香豆酸产量达到峰值(174.57±0.30)mg/L,相较于未添加时提高了将近1倍。通过运用合成生物学原理在酿酒酵母中实现了对香豆酸的高产,为后续的芪类化合物和黄酮类化合物生物合成奠定了基础。     

老年与青年小鼠慢性应激后抑郁样行为的观察

目的：探讨慢性应激后不同月龄小鼠抑郁样行为的变化,以及海马和前脑皮层胰岛素样神经营养因子-Ⅱ （IGF-Ⅱ）的作用。方法：昆明品系小白鼠3月龄（青年）和14月龄（老年）,随机分为青年对照组和青年应激组、老年对照组和老年应激组,每组12只、雌雄各半。多因素慢性应激21 d,建立抑郁小鼠模型。采用悬尾实验和蔗糖偏好实验评价小鼠的抑郁样行为;并且检测小鼠海马和前脑皮层IGF-Ⅱ的表达水平。结果：与青年对照组相比,老年对照组小鼠的累积不动时间明显增多（P<0.05）,蔗糖消耗度明显降低（P<0.05）,并且IGF-Ⅱ阳性神经元数目在海马CA1区、CA3区、齿状回（D G）和前脑皮层均明显减少（P<0.01或P<0.05）;慢性应激后,青年应激组小鼠的第一次静止不动时间、累积不动时间和蔗糖消耗度与其对照组比较均有显著性差异（P均<0.01）,IGF-Ⅱ阳性神经元数目在CA1、DG和前脑皮层均显著减少（P<0.05或P<0.01）;与老年对照组比较,老年应激组小鼠的第一次静止不动时间明显减少（P<0.05）、累积不动时间显著增加（P<0.0 5）和蔗糖消耗度明显减少（P<0.05）,海马CA1、CA3和DG区IGF-Ⅱ阳性神经元数目均显著减少（P <0.05或P<0.01）。结论：慢性应激后小鼠的抑郁样行为可能与海马和前脑皮层IGF-Ⅱ表达的下调密切相关。     

束缚应激对D-氨基半乳糖联合脂多糖诱导小鼠肝损伤的保护作用

目的探讨束缚应激对D-氨基半乳糖联合脂多糖（D–galactosamine and lipopolysaccharide combination,D＋L）诱导的小鼠肝损伤的保护作用。方法正常BALB/c小鼠随机分为正常对照组（con）、应激对照组（str）、模型组（D＋L）、束缚应激组（D＋L＋str）。con组小鼠常规饲养;str组小鼠给予定时定量的束缚应激;D＋L组小鼠腹腔注射D-氨基半乳糖和脂多糖的混合溶液,1次/2天;D＋L＋str组小鼠腹腔注射等量D＋L混合液后,给予与str组相同的束缚应激。第8周,各组小鼠取血检测血清AST、ALT,肝脏固定后HE及Masson染色观察小鼠肝脏结构、细胞形态及纤维化程度。结果第8周D＋L＋str组与D＋L组小鼠相比,血清ALT和AST显著降低（P〈0.01）,AST/ALT显著增高（P〈0.01）;HE及Masson染色显示,D＋L组小鼠肝小叶结构紊乱,出现结节性增生及大量上皮细胞核浓缩、溶解、坏死,枯否氏细胞浸润,而D＋L＋str组未见明显病理变化;纤维化程度评分显示,D＋L＋str组与D＋L组小鼠相比,病理评分与纤维显色吸光度值均显著降低（P〈0.05）。结论束缚应激对D＋L诱导的小鼠肝损伤具有一定保护作用。     

CFA注射致炎性疼痛过程中海马内BDNF的表达及作用研究

目的:探索完全弗氏佐剂(Complete Freund’s Adjuvant,CFA)致炎性疼痛后大鼠海马内脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)表达的变化及其作用。方法:雄性SD大鼠随机分为溶媒对照组和实验组,实验组大鼠左侧足底皮下注射CFA和生理盐水混合溶剂100μL,建立炎性疼痛模型,注射后大鼠分别存活1天、4天、7天、14天(n=20只/组)。在建模前和建模后不同时间点采用Von Frey纤维检测大鼠50%机械缩足阈值(paw withdrawal threshold,PWT)的变化。采用强迫游泳实验和糖水偏好实验检测大鼠抑郁样行为,采用RT-PCR检测不同时间点大鼠海马中BDNF m RNA的水平,采用ELISA和免疫组织化学法检测BDNF的表达变化。结果:足底注射CFA后1天50%PWT下降,持续至14天仍低于基础值。在强迫游泳实验中,注射CFA7天后的大鼠不动时间百分比增加,一直持续到CFA注射后14天。糖水偏好实验中注射CFA后7天组、14天组大鼠表现出对糖水偏好的降低,提示注射CFA后7天大鼠出现抑郁样行为并持续到第14天。在足底注射CFA第7天后BDNF m RNA和BDNF的水平达到高峰,第14天表达下调并基本恢复正常水平。结论:结果提示,足底注射CFA能诱导大鼠产生炎性痛,CFA注射7天后出现抑郁样行为,此时海马内BDNF m RNA和BDNF蛋白水平均上调,可能与足底注射CFA后出现的抑郁样行为的发生密切相关。     

脑源性神经营养因子与抑郁症的研究进展

脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)是人体内含量最多的神经营养因子,在神经系统的发育和功能维持中起至关重要的作用.研究表明,抗抑郁剂通过提高BDNF表达来促进神经细胞的生存,增加突触可塑性及神经发生.     

不同焦虑程度青少年首发广泛性焦虑障碍患者血清NPY、5-HT、BDNF的变化及其与生活应激、炎症因子和记忆功能的相关性分析

摘要 目的：探讨不同焦虑程度青少年首发广泛性焦虑障碍（GAD）患者血清神经肽Y（NPY）、5-羟色胺（5-HT）、脑源性神经营养因子（BDNF）的变化及其与生活应激、炎症因子和记忆功能的相关性。方法：选择2019年1月至2021年12月成都市精神卫生中心收治的147例青少年首发GAD患者,根据广泛性焦虑量表（GAD-7）分为轻度焦虑组（5-9分,50例）、中度焦虑组（10-14分,65例）、重度焦虑组（15-21分,32例）。检测血清NPY、5-HT、BDNF、C反应蛋白（CRP）、白细胞介素（IL）-1α、IL-6水平,采用学生生活应激问卷（SLSI）、延迟匹配测验（DMS）评估生活应激水平和记忆功能。比较组间血清NPY、5-HT、BDNF、CRP、IL-1α、IL-6水平以及SLSI、DMS差异,分析血清NPY、5-HT、BDNF水平与血清CRP、IL-1α、IL-6水平及SLSI、DMS的相关性。结果：重度焦虑组血清NPY、5-HT、BDNF水平低于中度焦虑组和轻度焦虑组（P＜0.05）,且中度焦虑组低于轻度焦虑组（P＜0.05）,重度焦虑组CRP、IL-1α、IL-6水平以及SLSI评分高于中度焦虑组和轻度焦虑组（P＜0.05）,且中度焦虑组高于轻度焦虑组（P＜0.05）。重度焦虑组总延迟反应时间、无延迟反应时间长于中度焦虑组和轻度焦虑组（P＜0.05）,且中度焦虑组长于轻度焦虑组（P＜0.05）;重度焦虑组总延迟正确数、无延迟正确数少于中度焦虑组和轻度焦虑组（P＜0.05）,且中度焦虑组少于轻度焦虑组（P＜0.05）。青少年首发GAD患者血清NPY、5-HT、BDNF水平与SLSI评分、CRP、IL-1α、IL-6、总延迟反应时间、无延迟反应时间呈负相关（P＜0.05）,与总延迟正确数、无延迟正确数呈正相关（P＜0.05）。结论：青少年首发GAD患者随着焦虑程度加重,其生活应激强度增强、炎症因子水平升高,记忆功能减弱,且均与患者血清NPY、5-HT、BDNF水平降低有关。     

电针早期干预对创伤后应激模型大鼠的行为及前额叶皮质BDNF、IL-1β和IL-6水平的影响

目的:观察电针(Electroacupuncture,EA)早期干预对创伤后应激(Posttraumatic stress disorder,PTSD)模型大鼠的焦虑样行为及前额叶皮质(Prefrorntal cortex,PFC)中脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)、白介素1β(Interleukin-1beta,IL-1β)和白介素6(Interleukin-6,IL-6)水平的影响。方法:将32只雄性SD大鼠经环境适应后,随机分为Sham组、Sham+EA组、ESPS组和ESPS+EA组,每组8只。对ESPS组和ESPS+EA组大鼠进行增强型单次延长应激(Enhanced single prolonged stress,ESPS)造模处理,其他两组不接受ESPS,但是置于同一实验室环境。造模结束后24 h,各组大鼠进行EA干预:Sham+EA组和ESPS+EA组的大鼠每天接受EA刺激(百会穴,1 m A,2/15 Hz)30 min,连续1周;另外两组给予假刺激(无电流)每天30 min,连续1周。静置一周后,采用旷场和高架十字实验观察各组大鼠的行为,之后处死大鼠,分别用蛋白质印迹法和酶联免疫法(Enzyme-linked immunosorbent assay,ELISA)检测各组大鼠PFC中BDNF的表达水平以及IL-1β和IL-6的水平。结果:(1)ESPS处理导致大鼠焦虑样行为,在旷场中心区运动距离和探索时间百分比减少,在高架十字开臂运动距离及停留时间百分比减少。ESPS组大鼠PFC中BDNF表达下降,IL-1β和IL-6的水平升高;(2)EA早期干预可以改善大鼠的焦虑样行为,提高ESPS模型大鼠PFC中BDNF的表达,降低IL-6的水平,对IL-1β的影响无统计学差异。结论:EA早期干预改善了ESPS诱导的大鼠焦虑样的行为,这可能与其增加了PFC中BDNF表达,降低了炎性因子IL-6的表达有关。     

Age-dependent effects of chronic stress on brain plasticity and depressive behavior

Exposure to chronic mild stress (CMS) is known to induce anhedonia in adult animals, and is associated with induction of depression in humans. However, the behavioral effects of CMS in young animals have not yet been characterized, and little is known about the long-term neurochemical effects of CMS in either young or adult animals. Here, we found that CMS induces anhedonia in adult but not in young animals, as measured by a set of behavioral paradigms. Furthermore, while CMS decreased neurogenesis and levels of brain-derived neurotrophic factor (BDNF) in the hippocampus of adult animals, it increased these parameters in young animals. We also found that CMS altered alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor GluR1 subunit levels in the hippocampus and the nucleus accumbens of adult, but not young animals. Finally, no significant differences were observed between the effects of CMS on circadian corticosterone levels in the different age groups. The substantially different neurochemical effects chronic stress exerts in young and adult animals may explain the behavioral resilience to such stress young animals possess.     

A novel trimeric peptide, Neuropep-1-stimulating brain-derived neurotrophic factor expression in rat brain improves spatial learning and memory as measured by the Y-maze and Morris water maze

Abundant studies have shown possible links between low levels of brain-derived neurotrophic factor (BDNF) and neurological diseases such as Alzheimer's disease, Parkinson's disease, and depression, as well as stress and anxiety; therefore, BDNF could be a therapeutic target for neurological disorders. In the present study, a positional scanning-synthetic peptide combinatorial library was utilized to identify a peptide modulator of BDNF expression in the hippocampal neuronal cell line, H19-7. A novel tripeptide (Neuropep-1) induced a significant increase of BDNF mRNA and protein levels in H19-7 cells. Pre-treatment of TrkB inhibitor (K252a) did not block Neuropep-1-induced BDNF up-regulation. These results indicate that Neuropep-1 may up-regulate BDNF expression that might be independent of the TrkB receptor pathway. Tail vein injection of Neuropep-1 significantly up-regulated BDNF expression, TrkB phosphorylation, and its downstream signals including activation of Akt, ERK, and cAMP response element binding in the rat hippocampus. To evaluate improvement of spatial learning and memory (SLM) by Neuropep-1-induced BDNF up-regulation, the Y-maze and Morris water maze tests were performed. These results showed Neuropep-1 injection improved SLM performance with increase of BDNF and TrkB expression, activation of TrkB downstream signals in rat hippocampus compared with the control group. However, phosphorylation levels of TrkB were not changed when it was normalized to the level of TrkB expression. The difference on TrkB phosphorylation in Neuropep-1-injected rats may be affected by behavioral tests. These results suggest that Neuropep-1 may improve SLM via activation of the BDNF/TrkB signaling pathway in the rat hippocampus. Therefore, our findings represent that Neuropep-1 might be a potential candidate for treatment of learning and memory disorders as well as neurological diseases involving the abnormal expression of BDNF.     

二氢杨梅素改善慢性社会挫败应激小鼠认知与情感障碍*

目的:探索二氢杨梅素(DHM)对慢性社会挫败应激小鼠认知与情感障碍的作用及其可能机制。方法:将C57BL/6J小鼠随机分成对照组(Control)、慢性社会挫败应激组(CSDS)和慢性社会挫败应激+DHM组(CSDS+DHM),每组14只,每天将两个应激组小鼠放入ICR攻击鼠的饲养笼中10 min,之后取出放于ICR攻击鼠饲养笼的旁边笼中,连续应激10 d,在应激5 d后,每天按10 ml/kg的量分别腹腔注射一次2%的DMSO或20 mg/kg的DHM(分散于2% DMSO中),连续注射5 d,之后每组取10只小鼠进行新颖物体识别测试、Y迷宫测试、社会交互和旷场测试、行为学测试,剩余4只小鼠于实验结束后24 h内断头取脑,采用Western blot法检测海马组织SIRT1水平。结果:与Control组比较,CSDS组小鼠的学习记忆显著降低,焦虑水平显著升高,在悬尾测试(TST)和强迫游泳测试(FST)中的不动时间显著升高,海马SIRT1蛋白水平显著降低(P均＜0.05或P＜0.01);与CSDS组比较,CSDS+DHM组小鼠学习记忆显著提高,小鼠焦虑水平显著降低,在TST和FST中不动时间显著降低,海马SIRT1蛋白水平显著升高(P均＜0.05或P＜0.01)。结论:DHM可改善CSDS诱导小鼠的认知障碍、焦虑样行为和抑郁样行为,并提高海马SIRT1蛋白的表达水平。     

Acute forced exercise increases Bdnf IV mRNA and reduces exploratory behavior in C57BL/6J mice

Acute exercise has been shown to improve memory in humans. Potential mechanisms include increased Bdnf expression, noradrenergic activity and modification of glutamate receptors. Because mice are commonly used to study exercise and brain plasticity, it is important to explore how acute exercise impacts behavior in this model. C57BL/6J mice were assigned to three groups: control, moderate‐intensity running, and high‐intensity running. Control mice were placed on a stationary treadmill for 30 minutes and moderate‐ and high‐intensity mice ran for 30 minutes at 12 and 15‐17 m/min, respectively. Mice were sacrificed immediately after running and the hippocampus removed. Total Bdnf, Bdnf exon IV, and glutamate receptor subunits were quantified with quantitative polymerase chain reaction. Total and phosphorylated GluR1 (Ser845 and Ser831) protein was quantified following immunoblotting. Utilizing the same protocol for control and high‐intensity running, object location memory was examined in a separate cohort of mice. Anxiety‐like behavior was assessed in the open field task (OFT) in a third cohort of mice that were separated into four groups: control‐saline, control‐DSP‐4, acute exercise‐saline, and acute exercise‐DSP‐4. DSP‐4 was used to lesion the central noradrenergic system. We observed higher Bdnf IV mRNA in high‐intensity runners compared to controls, but no effects of acute exercise on memory. In the OFT, runners traveled less distance and spent more time grooming than controls. DSP‐4 did not attenuate the effects of exercise. A single bout of exercise increases Bdnf IV mRNA in an intensity‐dependent manner; however, high‐intensity running reduces exploratory behavior in C57BL/6J mice.     

Amphetamine-induced locomotion and gene expression are altered in BDNF heterozygous mice

Administration of amphetamine overstimulates medium spiny neurons (MSNs) by releasing dopamine and glutamate from afferents in the striatum. However, these afferents also release brain-derived neurotrophic factor (BDNF) that protects striatal MSNs from overstimulation. Intriguingly, all three neurochemicals increase opioid gene expression in MSNs. In contrast, striatal opioid expression is less in naive BDNF heterozygous (BDNF(+/-)) vs. wild-type (WT) mice. This study was designed to determine whether partial genetic depletion of BDNF influences the behavioral and molecular response to an acute amphetamine injection. An acute injection of amphetamine [5 mg/kg, intraperitoneal (i.p.)] or saline was administered to WT and BDNF(+/-) mice. WT and BDNF(+/-) mice exhibited similar locomotor activity during habituation, whereas BDNF(+/-) mice exhibited more prolonged locomotor activation during the third hour after injection of amphetamine. Three hours after amphetamine injection, there was an increase of preprodynorphin mRNA in the caudate putamen and nucleus accumbens (Acb) and dopamine D(3) receptor mRNA levels were increased in the Acb of BDNF(+/-) and WT mice. Striatal/cortical trkB and BDNF, and mesencephalic tyrosine hydroxylase mRNA levels were only increased in WT mice. These results indicate that BDNF modifies the locomotor responses of mice to acute amphetamine and differentially regulates amphetamine-induced gene expression.     

慢性束缚应激对SD和Wistar大鼠学习记忆能力的影响

目的探讨慢性束缚应激对Wistar、SD两种品系大鼠学习记忆能力的影响,为应激模型中实验动物的选择提供依据。方法对两种品系大鼠(Wistar、SD)采用每天束缚10 h,束缚28 d建立慢性应激模型。采用物体认知新物体识别实验和Morris水迷宫空间学习、工作记忆行为学检测方法,观察束缚应激对两种品系实验动物学习记忆能力的影响。结果束缚28 d后,物体识别实验中,Wistar、SD模型组的辨别指数(discrimination index,DI)均低于对照组,但只有SD两组间差异存在显著性(P0.05);水迷宫空间学习阶段,SD模型组潜伏期高于对照组,第5天差异有显著性(P0.05),而Wistar模型组与对照组间的潜伏期没有差异;水迷宫工作记忆阶段,SD大鼠模型组与正常组比较,潜伏期显著增加(P0.05),Wistar模型大鼠的潜伏期与对照组比较没有显著差异。结论新物体识别实验和水迷宫实验,这两种反应动物不同学习记忆能力的行为学实验结果都表明,慢性束缚应激(10 h,28 d)对SD大鼠学习记忆能力的损伤较Wistar大鼠明显。SD大鼠可能更适合作为慢性应激所致学习记忆损伤动物模型。