单侧磨牙缺失对老年学习记忆减退大鼠基底前脑胆碱能系统的影响

目的:探讨单侧缺牙对不同学习记忆能力老年大鼠基底前脑胆碱能系统的影响。方法:用Morris水迷宫筛选出老年记忆减退鼠和老年记忆正常鼠,拔除单侧磨牙后2个月,用免疫组化和组织化学染色观察对其斜角带核垂直支胆碱能神经元和海马CA1区、前额皮质胆碱能纤维密度的影响。结果:斜角带核垂直支ChAT阳性细胞数和海马CA1区、前额皮质AChE阳性纤维密度在老年记忆减退鼠中,拔牙组较对照组(未拔牙)明显下降;海马CA1区AChE阳性纤维密度在老年记忆正常鼠中,拔牙组较对照组明显下降。结论:单侧磨牙缺失可加速老年学习记忆减退鼠基底前脑胆碱能系统的损害。     

植物雌激素对去卵巢大鼠基底前脑胆碱能神经元的影响

目的：观察植物雌激素对去卵巢大鼠基底前脑胆碱能神经元表达的影响，探讨植物雌激素在中枢神经系统的保护作用及机制。方法：采用乙酰胆碱转移酶(ChAT)免疫组织化学ABC法，观察去卵巢大鼠5w后各组基底前脑内侧隔核(MS)，斜角带垂直支(VDB)胆碱能神经元的数目。结果：与去卵巢对照组相比，植物雌激素用药组、雌激素用药组的内侧隔核，斜角带垂直支胆碱能神经元数目明显升高(P＜0．05)，与假手术组差别不明显。结论：本研究提示植物雌激素能明显增加去卵巢大鼠基底前脑胆碱能神经元的表达，从而对中枢神经系统退行性病变起保护作用，并有望预防和治疗老年性痴呆。     

康复新对去卵巢大鼠学习记忆能力和基底前脑胆碱能神经元的影响

目的 探讨康复新对去卵巢大鼠的学习记忆能力的影响及其可能机制.方法 3月龄健康雌性SD大鼠36只,随机分成4组,即假手术组、去卵巢对照组、康复新低剂量组和康复新高剂量组,分别进行干预.8周后用Y迷宫检测大鼠的空间学习记忆能力,用免疫组化染色检测大鼠基底前脑不同区域胆碱能神经元的数目.结果 康复新高剂量组大鼠"学会"所需总训练次数、训练错误次数及记忆检测时错误反应次数与去卵巢对照组比较明显减少(P＜0.05),与假手术组相比差异无统计学意义(P＞0.05);康复新液高、低剂量组大鼠基底前脑内侧隔核(MS)、斜角带核垂直支(vDB)和水平支(hDB)的ChAT阳性神经元数量增多;高剂量组基底前脑各区的ChAT阳性神经元数明显高于去卵巢对照组(P＜0.05),与假手术组相比差异无统计学意义(P＞0.05);而且康复新高剂量组大鼠vDB和hDB的ChAT阳性神经元数明显高于康复新低剂量组(P＜0.05).结论 康复新液可显著改善去卵巢大鼠学习记忆能力,其作用可能是通过增加基底前脑胆碱能神经元的功能实现的;康复新液有望成为防治雌激素撤退引起的神经功能障碍的药物.     

银杏叶提取物改善AD模型鼠学习记忆功能的作用

目的 :研究银杏叶提取物 (EGb)对早老性痴呆 (AD)模型鼠学习记忆等认知功能的影响和对基底前脑隔区胆碱能神经元的保护作用。方法 :大鼠随机分成预防组、治疗组和对照组。各组切割右侧海马伞后分别用EGb(预防组及治疗组 )和蒸馏水 (对照组 )灌胃连续 6周。其中预防组在手术前先用EGb灌胃 2周。各组在术后次日及灌胃 6周后进行行为学检测。脑切片经Nissl、NOS组织化学和ChAT免疫组织化学染色 ,观察损伤侧内侧隔核和斜角带垂直支中NOS和ChAT阳性神经元的变化 ,并对ChAT阳性神经元作图像分析。数据分别用方差分析、SNK检验及 χ2 检验作统计学处理。结果 :行为学检测证实 ,EGb用药组AD模式鼠的学习记忆等认知功能较对照组明显改善 ,其中预防组效果又较治疗组为好 ;形态学检测证实 ,EGb用药组AD模式鼠损伤侧内侧隔核和斜角带垂直支中NOS、ChAT阳性神经元数目及ChAT阳性神经元的面积和周径等均优于对照组 ,预防组结果又优于治疗组。结论 :EGb对AD模型鼠学习记忆等认知功能障碍有一定的改善作用 ,这一作用是通过保护基底前脑隔区胆碱能神经元而实现的 ,其中预防效果比治疗效果更优     

胰岛素与尼莫地平对大鼠基底前脑胆碱能神经元及空间学习记忆的影响

目的探讨胰岛素与尼莫地平对基底前脑胆碱能神经元与学习记忆在1型糖尿病脑病发生中的影响。方法将成年雄性Wistar大鼠随机分成糖尿病组、干预组、载体组及正常对照组。用链脲佐菌素成功建立成1型糖尿病模型12周后,对干预组大鼠每日皮下注射长效胰岛素(3 IU)、腹腔注射尼莫地平(20 mg/kg),连续用药6周,在相同条件下对载体组大鼠注射等体积的无药物液体,但对糖尿病组或正常对照组大鼠未进行任何处理。应用Morris水迷宫及胆碱乙酰转移酶(ChAT)免疫组化方法,分别测定各组大鼠的空间学习记忆能力及基底前脑胆碱能神经元的变化。结果糖尿病组大鼠内侧隔核、斜角带核垂直支、斜角带核水平支的ChAT阳性神经元数均明显减少(P<0.05),空间学习记忆能力也明显下降(P<0.05);干预组大鼠以上三个核团的ChAT阳性神经元数与学习记忆能力均明显大于糖尿病组大鼠(P<0.05),但干预组的各项指标仍然明显低于载体组大鼠或正常对照组大鼠(P<0.05)。结论在糖尿病的长期自然发展过程中,若不进行治疗则可累及到基底前脑胆碱能神经元,导致学习记忆障碍,这可能是引发1型糖尿病脑病的一个负性因素;此时联合应用胰岛素与尼莫地平仍可有效遏制该脑病向纵深发展的恶性势头。     

侧脑室注射192-IgG-saporin致痴呆动物模型的实验研究

建立老年性痴呆模型大鼠,并观察其学习记忆能力及基底前脑胆碱能神经元数目的变化。在成年SD大鼠左侧侧脑室注射免疫毒素192-IgG-saporin(2.5μg/5μl),3周后行Y迷宫检测其学习和记忆能力;4周后处死大鼠,采用免疫组化结合图像分析技术观察各组大鼠基底前脑ChAT阳性神经元数目的变化。结果显示:模型组大鼠的学习记忆能力与正常组相比明显下降(P<0.01);模型组基底前脑的内侧隔核(MS)和斜角带垂直部(VDB)胆碱能神经元数目分别减少至正常组的9.70%和14.09%,与正常组相比均明显下降(P<0.01);学习、记忆能力与基底前脑胆碱能神经元数目密切相关。上述结果表明应用192-IgG-saporin免疫毒素能成功建立AD大鼠动物模型,该模型可用于抗痴呆药物的筛选及药效的评价。     

内侧隔核与学习记忆

基底前脑胆碱能系统一直被认为与动物的学习记忆能力密切相关。内侧隔核是基底前脑系统的一个重要核团,与周围结构的纤维联系比较复杂。它通过隔海马通路影响动物的学习与空间记忆能力。本文主要是对内侧隔核的解剖关系、内侧隔核与海马和学习记忆的关系以及影响内侧隔核胆碱能神经元功能变化的因素等方面进行综述。     

Genistein对去卵巢大鼠基底前脑胆碱能神经元影响的体内研究

本文旨在研究染料木素(genistein)对去卵巢大鼠基底前脑胆碱能神经元的影响。雌性大鼠双侧卵巢切除2周后用genistein和雌激素替代治疗1周。称子宫重量以确定手术是否成功及雌二醇(E2)的治疗是否有效。用免疫组化染色、RT-PCR和Westernblot等方法对胆碱能神经元数量、ChAT基因和蛋白的表达量进行检测。结果显示:去卵巢3周后子宫变轻,雌激素替代治疗能增加去卵巢子宫的重量,而genistein替代治疗对去卵巢子宫的重量影响不明显;去卵巢3周后,内侧隔核(MS)和斜角带垂直臂核(VDB)内的胆碱能神经元数量、ChAT基因和蛋白的表达量均明显减少,雌激素和genistein替代治疗后能显著增加去卵巢大鼠MS和VDB内的胆碱能神经元数量、ChAT基因和蛋白的表达量。本研究结果提示:genistein对去卵巢大鼠基底前脑胆碱能神经元具有类似雌激素样神经保护作用,而对子宫影响不明显。     

神经干细胞移植对老年痴呆模型鼠基底前脑胆碱能神经元和学习记忆能力的影响

目的:探讨神经干细胞移植对老年性痴呆模型鼠基底前脑胆碱能神经元及学习记忆能力的影响.方法:利用无血清培养技术获得新生SD鼠的基底前脑神经干细胞,切断SD大鼠左侧穹隆海马伞,基底前脑注射神经干细胞.4周后行Y迷宫测试学习记忆能力,免疫组化结合图像分析技术观察各组大鼠基底前脑胆碱能神经元变化.结果:损伤组损伤侧的内侧隔核(MS)和斜角带核(VDB)的NGFR阳性神经元大量减少,分别减少59.7%和5 1.4%.NSC移植组损伤侧的NGFR阳性神经元得到补充和保护,MS和VDB细胞数分别下降22.0%和26.1%.同时,NSC移植组损伤侧MS的NGFR阳性神经元的面积、周长显著增大(P＜0.01),灰度显著增加(P＜0.01);损伤侧VDB的NGFR阳性神经元的面积明显增大且灰度明显增加(P＜0.05),周长显著增大(P＜0.01).Y迷宫测试结果显示,NSC移植组大鼠的空间学习能力得到明显改善(P＜0.05),记忆能力得到显著提高(P＜0.01),基底前脑NGFR阳性细胞数与大鼠的空间学习记忆能力呈正相关.结论:神经干细胞移植对老年性痴呆模型鼠基底前脑胆碱能神经元有明显的补充和保护作用,同时大鼠的学习记忆能力得到明显的改善.     

胰岛素促进基底前脑胆碱能神经元树突的增生

本实验采用２月龄ＳＤ大鼠３０只，建立隔－海马通路损伤模型，分别存活２和４周．实验用药组给予胰岛素脑室内注射（０．６ｕ／次／３ｄ）．到期动物用Ｇｏｌｇｉ－Ｃｏｘ改良技术染片，并用ＣａｍｅｒａＬｕｃｉｄａ描绘出基底前脑内侧隔核和斜角带核神经元全貌，按Ｓｈｏｌｌ方法分析神经元树突结构．结果显示，基底前脑内侧隔核和斜角带核神经元树突结构在损伤后发生较大变化，神经元树突野明显缩小，但在胰岛素用药组，树突的截点数，总长均大于对照组（Ｐ＜０．０１）．Ｓｈｏｌｌ线性回归分析结果显示，用药组神经元树突的截距大于对照组（Ｐ＜０．０５），斜率小于对照组（Ｐ＜０．０５）．因此，本文认为胰岛素具有减少损伤后基底前脑内侧隔核和斜角带核神经元树突的丢失．促讲其增生的作用．     

老年性学习记忆减退大鼠新皮质和海马结构胆碱能纤维的定量研究

用Ｍｏｒｒｉｓ水迷宫行为检测方法以青年组平均逃避潜伏期９５％和９９％正常值范围上限值为界将老年大鼠分为学习记忆正常组（老年正常组）和学习记忆减退组（老年减退组）,以Ｈｅｄｒｅｅｎ等推荐的ＡＣｈＥ组织化学染色方法结合形态计量方法对各组大鼠的额、枕、内嗅皮质、海马ＣＡ１区多形层、腔隙分子层和齿状回分子层外带的胆碱能纤维密度进行分析,结果显示老年减退组较老年正常组、青年组各层（除枕叶外）ＡＣｈＥ阳性纤维数量均明显减少（Ｐ０．０５,Ｐ＜０．０１）。老年正常组与青年组相比各层阳性纤维数量有所减少,但除海马ＣＡ１区腔隙分子层差异显著外,其余差异均无显著性。相关分析结果表明大鼠各层ＡＣｈＥ阳性纤维数量与其平均逃避潜伏期呈负相关关系,与原平台象限游泳距离占总距离百分比呈正相关关系。本研究提示老年性学习记忆能力减退与新皮质、海马结构胆碱能纤维溃变密切相关。     

Age-related changes in rostral basal forebrain cholinergic and GABAergic projection neurons: relationship with spatial impairment

Both cholinergic and GABAergic projections from the rostral basal forebrain contribute to hippocampal function and mnemonic abilities. While dysfunction of cholinergic neurons has been heavily implicated in age-related memory decline, significantly less is known regarding how age-related changes in codistributed GABAergic projection neurons contribute to a decline in hippocampal-dependent spatial learning. In the current study, confocal stereology was used to quantify cholinergic (choline acetyltransferase [ChAT] immunopositive) neurons, GABAergic projection (glutamic decarboxylase 67 [GAD67] immunopositive) neurons, and total (neuronal nuclei [NeuN] immunopositive) neurons in the rostral basal forebrain of young and aged rats that were first characterized on a spatial learning task. ChAT immunopositive neurons were significantly but modestly reduced in aged rats. Although ChAT immunopositive neuron number was strongly correlated with spatial learning abilities among young rats, the reduction of ChAT immunopositive neurons was not associated with impaired spatial learning in aged rats. In contrast, the number of GAD67 immunopositive neurons was robustly and selectively elevated in aged rats that exhibited impaired spatial learning. Interestingly, the total number of rostral basal forebrain neurons was comparable in young and aged rats, regardless of their cognitive status. These data demonstrate differential effects of age on phenotypically distinct rostral basal forebrain projection neurons, and implicate dysregulated cholinergic and GABAergic septohippocampal circuitry in age-related mnemonic decline.     

Recognition of novel objects and their location in rats with selective cholinergic lesion of the medial septum

The importance of cholinergic neurons projecting from the medial septum (MS) of the basal forebrain to the hippocampus in memory function has been controversial. The aim of this study was to determine whether loss of cholinergic neurons in the MS disrupts object and/or object location recognition in male Sprague-Dawley rats. Animals received intraseptal injections of either vehicle, or the selective cholinergic immunotoxin 192 IgG-saporin (SAP). 14 days later, rats were tested for novel object recognition (NOR). Twenty-four hours later, these same rats were tested for object location recognition (OLR) (recognition of a familiar object moved to a novel location). Intraseptal injections of SAP produced an 86% decrease in choline acetyltransferase (ChAT) activity in the hippocampus, and a 31% decrease in ChAT activity in the frontal cortex. SAP lesion had no significant effect on NOR, but produced a significant impairment in OLR in these same rats. The results support a role for septo-hippocampal cholinergic projections in memory for the location of objects, but not for novel object recognition.     

Effects of gonadectomy on immunoreactivity for choline acetyltransferase in the cortex, hippocampus, and basal forebrain of adult male rats

Androgens are known to affect cognitive and mnemonic aspects of spatial processing. The cholinergic system is thought to play an important role in cognition and memory, but little is known about the interaction between androgen and cholinergic neurons. The present study focused on the effects of testosterone on the cholinergic neurons in the anterior cingulate cortex, the posterior parietal cortex, the hippocampus, and the basal forebrain including the medial septum, i.e., regions related to spatial processing. We examined choline acetyltransferase (ChAT) immunoreactivity in three groups of adult male rats: sham-operated (Sham), 28-day gonadectomized (GDX), and 28-day gonadectomized with immediate implantation of testosterone propionate (GDX+TP). Comparison of the Sham and GDX+TP groups demonstrated that the GDX group had significantly decreased cell counts of ChAT-immunoreactive neurons in anterior cingulate cortex layer II/III, posterior parietal cortex layer II/III, and the medial septum, but not in the other basal forebrain subregions examined (the horizontal part of the diagonal band of Broca and the substantia innominata). The GDX group also had significantly reduced hippocampal ChAT-immunoreactive fiber pixel density. The GDX+TP group maintained ChAT-immunoreactive cell counts in the anterior cingulate cortex, posterior parietal cortex, and medial septum equivalent to those in the Sham group. Less than 1% of identified cells showed colocalization of immunoreactivity for ChAT and androgen receptor in the cell bodies of the cortex and basal forebrain.Our observations demonstrate that the presence or absence of testosterone for 4 weeks influenced the cholinergic population region-specifically in the adult rat brain.     

Microanatomical and electrophysiological changes of the rat dentate gyrus caused by lesions of the nucleus basalis magnocellularis

The effect of unilateral or bilateral lesions of the nucleus basalis magnocellularis (NBM) on the dentate gyrus of the hippocampus were assessed using microanatomical and electrophysiological techniques. NBM is the main cholinergic basal forebrain nucleus that supplies the fronto-parietal cortex. Lesions were induced using the neurotoxin ibotenic acid or a radio-frequency system and did not affect glutamic acid decarboxylase activity both in the frontal cortex and in the hippocampus. At 4 weeks after lesioning, a loss of choline acetyltransferase (ChAT) activity and of ChAT-immunoreactive fibres was observed in the frontal cortex but not in the hippocampus and no changes in the density of granule neurons of the dentate gyrus or in the hippocampal long-term potentiation (LTP) were noticeable. At 8 weeks after lesioning the loss of both ChAT activity and of ChAT-immunoreactive fibres persisted in the frontal cortex of NBM-lesioned rats. Moreover, at this time a significant decrease in the density of granule neurons in the dentate gyrus accompanied by a reduced probability of dentate LTP induction were observed in both ibotenic acid- and radio-frequency-lesioned rats. These findings have shown that although NBM does not send direct cholinergic projections to the hippocampus, lesions of this cholinergic nucleus are accompanied by delayed neurodegenerative changes involving the dentate gyrus. This suggests the occurrence of indirect connections between NBM and the hippocampus, the functional relevance of which should be explored.     

免疫毒素192-IgG-saporin侧脑室注射建立阿尔茨海默病动物模型的实验研究

目的建立大鼠阿尔茨海默病(Alzheimer′sdisease,AD)动物模型,并观察其学习记忆能力及基底前脑胆碱能神经元改变。方法采用SD大鼠侧脑室注射192-IgG-saporin(2.5μg/5μl),21d后行Y迷宫检测,28d后处死大鼠,免疫组化观察基底前脑神经生长因子受体(NGFR)阳性神经元细胞数的变化。结果Y迷宫检测显示模型组大鼠的学习次数、记忆能力(107.38±9.34、3.75±0.71)较正常组明显下降(P<0.01)。免疫组化显示模型组损伤侧在内侧隔核(MS)和斜角带垂直支(VDB)的NGFR阳性神经元细胞数(7.50±1.77、15.00±2.27)与正常组对应侧比较分别减少81.96%和84.23%(P<0.01),MS和VDB的NGFR阳性神经元面积和周长降低(P<0.05),灰度值升高(P<0.05)。结论免疫毒素192-IgG-saporin侧脑室注射可以模拟AD行为学改变和部分病理学特征。     

神经干细胞与血管性痴呆大鼠海马胆碱能神经元变化的相关性

背景：血管性痴呆患者存在额叶皮质及海马胆碱能神经元受损,可能是导致患者认知功能受损的形态学基础。 目的：探讨神经干细胞与血管性痴呆大鼠海马胆碱能神经元变化的相关性。 方法：纳入90只SD大鼠,随机均分为3组,其中假手术组仅分离颈总动脉,模型组和神经干细胞移植组采用两血管结扎法建立血管性痴呆动物模型,神经干细胞移植组在建立血管性痴呆动物模型之后向大鼠海马CA1区注射5 μL神经干细胞,另外两组按照同样的操作注射相同剂量的生理盐水。移植后第3,7,14,30,60天,分别处死各组6只大鼠,采用S-P免疫组化法检测各组脑实质BrdU阳性细胞和ChAT阳性细胞分布情况,利用Morris水迷宫系统检测大鼠学习记忆能力。 结果与结论：BrdU阳性细胞主要分布在大脑皮质区以及海马区,尤其是血管周围。在基底核和丘脑以及室管膜区,可观察到少量BrdU阳性细胞存在。随着时间的推移,BrdU阳性细胞数目不断下降,到移植后60 d,仅存在少量BrdU阳性细胞存活。移植后不同时间模型组和神经干细胞移植组的ChAT阳性细胞数均显著大于假手术组(P < 0.05);模型组ChAT阳性细胞数显著低于神经干细胞移植组(P < 0.05)。模型组寻找平台时间显著长于假手术组,穿越平台次数显著少于假手术组(P < 0.05);神经干细胞移植组的寻找平台时间显著短于模型组,穿越平台次数显著大于模型组(P < 0.05)。结果表明神经干细胞可以在大鼠脑内存活并发生迁移,显著改善血管性痴呆大鼠学习记忆能力,相关机制可能与海马胆碱能神经元分化和生长有关。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程      

基底前脑巢蛋白免疫阳性神经元研究现状及展望

目的阐述基底前脑nestin免疫阳性神经元的研究现状,为后续研究提供依据。方法对近年发表的有关基底前脑nestin免疫阳性神经元的文献进行分析和综述。结果在人和大鼠的基底前脑存在着一群能表达nestin的成熟神经元,这群神经元是区别于胆碱能神经元和γ-氨基丁酸能神经元的独立的神经元。其形态和分布与胆碱能神经元相似,向海马、大脑皮质及丘脑投射,与学习记忆及神经元的可塑性有关。结论基底前脑nestin免疫阳性神经元的化学属性、纤维联系及电生理特征等有待于进一步研究。这些研究将有助于我们了解成熟神经元表达nestin的功能意义,并为相关疾病的诊治提供新的视角。