强迫游泳大鼠脑内信号分子ERK1/2磷酸化水平的变化

通过观察强迫游泳时大鼠脑内不同核团内ERK1/2磷酸化水平变化,探讨与负性心理应激有关的脑内环路。将大鼠置于高60cm、水深约30cm的玻璃缸内,先预游15min,24h后进行5min的强迫游泳,观察大鼠游泳过程中的不动时间。游泳完毕后将大鼠灌流处死,对全脑组织进行磷酸化ERK1/2(pERK1/2)的免疫组织化学染色及其与酪氨酸羟化酶(TH)在部分核团内的免疫荧光双标细胞。强迫游泳后前额叶皮质、外侧隔区、下丘脑室旁核、海马CA13区、杏仁内侧亚核和皮质亚核、孤束核等脑区/核团中pERK1/2阳性细胞数显著增多;而杏仁中央亚核、下丘脑视上核内的磷酸化ERK1/2蛋白水平下降,阳性细胞数明显减少。免疫荧光双标结果表明,孤束核内部分pERK1/2阳性细胞呈TH免疫反应阳性。上述结果表明,以上脑区/核团内的神经元可能和负性心理应激的中枢调控有关,ERK1/2信号通路参与了其调控过程。此外,孤束核中的儿茶酚胺能神经元可能参与了心理应激的脑内活动。     

磷酸化的细胞外信号调节蛋白激酶1/2在正常小鼠脑内的免疫细胞化学定位

细胞外信号调节蛋白激酶(ERK)1/2是重要的信号转导分子。现已知在正常动物的中枢神经系统内有其活化形式即磷酸化的ERK1/2(pERK1/2)分子的存在,但其在小鼠脑内的分布目前还没有全面的观察。本研究用免疫组织化学技术(ABC法)研究了pERK1/2样免疫反应阳性产物在脱臼处死的正常小鼠全脑内的分布。结果发现pERK1/2在正常小鼠脑内有广泛的表达,阳性产物主要存在于神经元,亦见于个别白质内的胶质细胞,脑膜及室管膜细胞也有表达。强阳性表达的核团主要有:岛皮质、视听皮质、边缘前皮质、扣带前皮质、海马垂直部、弓状核、蓝斑和小脑Purkinje细胞;中等阳性表达的核团主要有:感觉运动皮质、外侧隔区、内侧杏仁核、皮质杏仁核和外侧杏仁核、丘脑室旁核前部、视交叉上核、穹隆下器、终板血管器、前腹侧视前核和下丘脑背内侧核;弱阳性表达的核团主要有:视上核、下丘脑室旁核大细胞部、下丘脑后区、顶盖前区、室周灰质腹外侧柱、A5区、孤束核和延髓腹外侧网状结构等。本文结果观察到pERK1/2在正常小鼠脑内广泛存在,提示pERK1/2作为重要的信号转导分子,可能参与许多脑区在正常状态下的功能活动,揭示其分布特点为了解其在脑内的多样性功能提供了形态学依据。     

小鼠E-W核神经元中磷酸化ERK1/2在异氟醚麻醉-苏醒过程中的表达变化

为了观察小鼠脑内E-W核神经元中磷酸化的ERK1/2(pERK1/2)在异氟醚吸入麻醉-苏醒过程中的表达变化,为探讨E-W核在麻醉效应产生机制中的作用提供形态学证据。我们将36只8周龄雄性BALB/c小鼠随机分为6组。第1组为清醒对照组(Con);第2、3组为异氟醚麻醉组(Iso-1、Iso-2:分别吸入1.0MAC异氟醚5min和1h);4～6组为异氟醚麻醉苏醒组(W-1、W-2:吸入1.0MAC异氟醚5min后停药2min、30min;W-3:吸入1.0MAC异氟醚1h后停药30min)。用免疫组织化学方法(ABC法)观察各时间点E-W核内pERK1/2阳性细胞并计数;用荧光双重标记法进一步明确pERK1/2阳性神经元的性质。结果显示:正常清醒小鼠E-W核内pERK1/2阳性细胞数量很少(2.2±1.5);异氟醚麻醉过程中pERK1/2表达显著增高(阳性细胞计数,Iso-1∶40.9±8.1;Iso-2∶40.2±9.6,与清醒对照相比,P<0.001);苏醒30min时pERK1/2表达降至正常对照组水平(W-2∶2.1±2.2;W-3∶0.75±1.2)。pERK1/2阳性神经元部分呈促肾上腺皮质激素释放激素(CRF)阳性,部分是乙酰胆碱(ChAT)阳性。上述结果提示,异氟醚麻醉过程中小鼠脑内E-W核神经元被激活,ERK1/2信号通路可能通过兴奋CRF能和Ach能神经元对瞳孔反射及麻醉应激效应进行调控。     

异氟醚麻醉对脑内ERK1/2和PKCγ磷酸化水平的影响

目的:探讨异氟醚麻醉对脑内ERK1/2和PKCγ磷酸化水平的影响.方法:采用雄性BALB/c小鼠, 随机分为5组, 即对照组(Con):未麻醉;异氟醚麻醉5 min组(Iso-1);异氟醚麻醉1 h组(Iso-2);麻醉1 h后停药2 min组(E-1):异氟醚麻醉1 h后, 小鼠脱离麻醉环境2 min;麻醉1 h后停药1 h组(E-2):异氟醚麻醉1 h后, 小鼠脱离麻醉环境1 h.用异氟醚进行麻醉后进行Western blot.以β-Actin为内参, pERK A/Actin A为ERK表达水平指标, pPKCγ A/Actin A为pPKCγ表达水平指标.结果:在Con组, pERK1/2和pPKCγ呈现高表达状态, 给予异氟醚麻醉处理组(Iso-1和Iso-2组), pERK1/2和pPKCγ表达减弱(P＜0.05), 当异氟醚麻醉停止后(E-1和E-2组), pERK1/2和pPKCγ表达逐渐恢复, 与Con组相比无统计学差异, 与异氟醚处理组相比, 有统计学差异(P＜0.05).结论:异氟醚麻醉-苏醒过程中, 脑中部分核团pERK1/2和pPKCγ水平发生显著变化.     

磷酸化PKCγ在正常小鼠脑内的免疫组织化学定位

为了研究磷酸化的蛋白激酶Cγ(pPKCγ)在小鼠脑内的区域分布,为进一步了解其在脑内的功能提供线索。我们将BALB/c小鼠脱臼处死,灌流取脑,行免疫组织化学染色,观察pPKCγ阳性反应产物在脑内的分布。观察到pPKCγ阳性产物主要见于神经元的胞浆和突起中,在正常小鼠脑内表达广泛。仅很少量胶质细胞被染色,着色浅淡。海马CA1区锥体细胞,小脑的浦肯野氏细胞,大脑新皮质V层细胞,边缘前皮质、岛皮质的深层细胞以及前梨皮质的颗粒层细胞,外侧嗅束核、杏仁基底外侧核和杏仁外侧核的神经元,以及穹窿、锥体束纤维等均有强或较强的pPKCγ表达;吻侧丘脑大多数核团,尾侧丘脑的内侧膝状体核及外侧膝状体的背侧核,脑干耳蜗背侧核的表浅部位,三叉神经感觉核簇及巨细胞网状结构神经元中均有弱阳性表达。本实验研究揭示正常状态下小鼠脑内pPKCγ表达广泛,但有区域特异性,提示PKCγ可能参与正常状态下脑内部分脑区/核团神经元的功能活动。     

限制饮水对大鼠脑核团内蛋白激酶ERK1/2磷酸化水平的影响

目的研究限制饮水应激对大鼠脑内磷酸化蛋白激酶ERK1／2（pERK1／2）水平的影响。方法58只雄性Wistar大鼠分为对照组（C,n=4）、定时给水组（TW,n=18）、空瓶刺激组（EB,n=18）、限制饮水组（WR,n=18）,后3组动物同置一室。TW组、EB组和WR组再按限制饮水时间分为3d、7d和14d3个亚组。各实验组在最后一次实验刺激后1h用免疫组织化学方法观察脑内pERK1／2表达的变化。并对相关核团中pERK1／2阳性细胞的面积进行图像分析。结果与对照组相比。实验刺激后引起大鼠脑内下丘脑室旁核（PVN）、视上核（SON）、腹外侧隔区（LSV）、内侧杏仁核（MeA）、中央杏仁核（CeA）和孤束核（NTS）等核团的pERK1／2表达显著增强;其中,EB组和WR组在SON、LSV、MeA和CeApERK1／2的表达均显著强于TW组,且EB组在LSV、MeA、CeA和NTSpERK1／2的表达增强和回落的时间要显著早于WR组。除PVN仅与刺激时间有关外,其余核团均与刺激时间和方式双重因素有关。结论限制饮水应激激活脑内PVN、SON、LSV、MeA、CeA和NTS等核团。物理性应激和心理性应激激活的中枢核团活动有一定差别。     

大鼠同性别社会交往引起主嗅觉系统相关脑区pERK1/2表达变化

目的:探讨大鼠同性别社会交往行为脑内pERK1/2的表达与可能作用。方法:采用三箱室社会交往箱检测雄性大鼠同性别社会交往行为,运用免疫组织化学染色观察动物10 min社会交往行为后脑内pERK1/2的表达;采用10%硫酸锌(ZnSO4)滴鼻嗅觉剥夺后观察大鼠同性别社会交往行为以及脑pERK1/2的表达状况。结果:大鼠呈现明显的同性别社会交往偏好;社会交往后,pERK1/2在与主嗅觉系统相关的脑区(如主嗅球、内嗅皮质、梨状皮质等)以及眶额皮质、前扣带皮质等脑区表达明显增加;嗅觉剥夺后大鼠的同性别社会交往行为显著减少,pERK1/2在主嗅觉系统相关脑区表达明显下降。结论:主嗅觉系统参与了雄性大鼠同性别社会交往行为,pERK1/2表达水平变化随着社会交往行为改变而改变,提示ERK1/2信号通路可能参与大鼠同性别社会交往行为。     

不同标本制备法对小鼠小肠组织中ERK1/2和pERK1/2免疫组织化学定位的影响

目的:本研究针对丝裂原活化蛋白激酶(MAPK)家族成员细胞外信号调节激酶(ERK1/2),以及磷酸化的ERK1/2(pERK1/2),探讨不给任何刺激时,用不同标本制备法检测ERK1/2在小鼠小肠组织中的免疫组织化学定位。方法:分别应用灌流固定脱水法(PF-DH),浸泡固定脱水法(IM-DH),快速冻结-冻结置换法(QF-FS)制备的标本,通过免疫组织化学显色检测ERK1/2和pERK1/2在肠上皮中的定位。结果:应用PF-DH法,ERK1/2位于几乎所有上皮细胞的核中,而pERK1/2在上皮细胞中很难检测到。应用IM-DH法,ERK1/2位于所有上皮细胞的胞质和核内,pERK1/2仅位于小肠绒毛顶部的上皮细胞内,而不存在于肠隐窝区域的上皮细胞中。应用QF-FS法制备的标本中,ERK1/2定位于所有上皮细胞的胞质中,而pERK1/2主要存在于肠隐窝部位和肠绒毛顶部的上皮细胞中。结论:本研究结果提示,用不同的标本制备方法会影响ERK1/2的免疫组织化学定位。通过比较不同标本制备方法取材的小鼠小肠组织中的ERK1/2和pERK1/2的免疫组织化学定位,得出QF-FS法可能为最接近活体状态的小鼠小肠组织中的ERK1/2和pERK1/2定位的方法。     

去铁敏阻抑ob/ob小鼠海马脑区的Tau蛋白过度磷酸化

目的研究去铁敏(DFO)对ob/ob小鼠脑内Tau过度磷酸化的影响,以探讨铁沉积是否涉及糖尿病(DM)的神经病理。方法繁育12只6月龄ob/ob小鼠,随机分为DFO组和对照组(n=6),分别给予腹腔注射DFO(100 mg·kg^-1)或空白溶剂15d。采用免疫组织化学和Western blot方法,检测小鼠海马脑区的Tau蛋白磷酸化及其调控蛋白激酶和磷酸酶的表达变化;DAB增强的Perl’s染色检测海马铁离子的分布。结果DFO处理后,ob/ob小鼠海马脑区Tau蛋白无明显变化,而在Ser396和Thr231位点的磷酸化水平降低。相应地,DFO组小鼠脑内蛋白激酶GSK3β和CDK5的活性显著下调,磷酸酶PP2A及其活性上调。另外,DFO组小鼠海马脑区的铁染色强度减弱。结论DFO能够有效改善ob/ob小鼠海马脑区的Tau病理,为揭示铁参与DM诱发的神经病理提供了新证据。     

低氧预适应鼠脑海马组织内与cPKCγ相互作用的ERK1/2磷酸化水平降低

目的探讨与经典型蛋白激酶Cγ(cPKCγ)相互作用的细胞外信号调节激酶1/2(ERK1/2)的磷酸化水平在小鼠脑低氧预适应形成过程中的变化。方法用成年雄性BalB/c小鼠制备整体低氧预适应模型,将小鼠随机分为正常对照(H0)、早期低氧预适应(H3)和延迟性低氧预适应(H6)3组。应用免疫共沉淀,Western blot等方法检测胞质和膜相关成分中与cPKCγ相互作用的ERK1/2的磷酸化水平。结果小鼠海马组织中ERK1/2能与cPKCγ免疫共沉淀,且与H0组相比,H3及H6组ERK1/2的204位酪氨酸磷酸化水平明显降低(P<0.05)。结论小鼠海马组织中,cPKCγ与ERK1/2存在相互作用,且可能参与了脑低氧预适应的发生和发展。     

The Effect of Sevoflurane Inhalation on Gabaergic Neurons Activation: Observation on the GAD67‐GFP Knock‐In Mouse

The mechanisms underlying volatile anesthesia agents are not well elucidated. Emerging researches have focused on the participation of γ‐aminobutyric acid (GABA) neurons but there still lacks morphological evidence. To elucidate the possible activation of GABAergic neurons by sevoflurane inhalation in morphology, Fos (as neuronal activity marker) and GABA neurons double labeling were observed on the brain of glutamic acid decarboxylase (GAD) 67‐GFP knock‐in mice after sevoflurane inhalation. Twenty GAD67‐GFP knock‐in mice were divided into three groups: S1 group: incomplete anesthesia state induced by sevoflurane; S2 group: complete anesthesia state induced by sevoflurane; control(C) group. Sevoflurane induced a significant increase of Fos expression in the dorsomedial hypothalamic nucleus (DM), periaqueductal grey (PAG), hippocampus (CA1, DG), paraventricular thalamic nucleus (PV), lateral septal nucleus (LS), and cingulate cortex (Cg1 and Cg2) in S1 group compared to C group, and increase of Fos expression in S2 group compared to S1 group. In S2 group, Fos was only expressed in the medial amygdaloid nucleus (MeA), Edinger–Westphal (E–W) nucleus, arcuate hypothalamic nucleus (Arc) and the ventral part of paraventricular hypothalamic nucleus (PaV). Double immunofluroscent staining indicated that in LS, almost all Fos werepresent in GABAergic neurons. In CA1, DG, DM, cg1, cg2, and PAG, Fos was expressed as well, but only few were present in GABAergic neurons. Fos expression was very high in thalamus, but no coexistence were found as noGABAergic neuron was detected in this area. Our results provided morphological evidence that GABAergic transmission in specific brain areas may participate in the sevoflurane‐induced anesthesia. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

异丙酚诱导大鼠中枢FOS核蛋白表达的研究

目的　通过检测异丙酚静脉全麻诱导大鼠中枢FOS核蛋白的表达 ,明确静脉全身麻醉的中枢作用位点。方法　 2 1只Wistar大鼠随机分成 3组 :对照组 (C组 )腹腔注入生理盐水 2ml,异丙酚组 (P组 )腹腔注入异丙酚 10 0mg kg ,异丙酚作用后断尾刺激组 (S组 )。 1h后应用FOS蛋白免疫组织化学法 (ABC法 ) ,检测FOS免疫反应 (FOS IR ,immunityreactionofFOS)阳性神经元在大脑的分布。结果　C组可见部分散在FOS IR阳性神经元分布 ,P组FOS IR阳性神经元数比C组明显增多 (P <0 .0 1) ,并呈核特异性分布 ,S组在杏仁基底外侧核、丘脑室旁核、外侧缰核及海马回嗅觉小岛等核团发现FOS IR阳性神经元较P组分布增多 (P <0 .0 1)。结论　异丙酚在大鼠中枢神经系统有与其静脉麻醉作用相关的神经核团。     

异丙酚诱导GAD_(67)-GFP基因敲入小鼠意识消失过程中GABA能神经元的活化

探讨在系统性给予谷氨酸脱羧酶67-绿色荧光蛋白(GAD67-GFP)基因敲入小鼠异丙酚后诱导的意识消失作用中的GA-BA能神经元的活化情况。GAD67-GFP阳性小鼠20只,腹腔注射异丙酚130mg/kg(对照组腹腔注射相同体积的生理盐水)。分别在注射后5min,30min,1h进行行为学评分,随后立即处死并取脑,应用免疫组织化学观察神经元活化标记物Fos在全脑的表达分布并用免疫荧光双标的方法观察Fos与GABA能神经元的共存情况。行为学结果表明在给予异丙酚后5min和30min均能达到适度或深度麻醉效果,而1h时则处于过渡状态,行为学评分为5min时13分,30min时14分,1h时为9分。与对照组相比,Fos在海马CA1区、杏仁核、丘脑室旁核、下丘脑室旁核、梨状核、下丘脑腹内侧核、中脑导水管周围灰质的表达在三个时间点都有明显增加(P<0.05),在嗅球外丛状层有表达但与对照组相比无明显差异(P>0.05)。注射后5min、30min和1h下丘脑腹内侧核有Fos与GABA共存,有共存的细胞占该区域Fos阳性神经元的80.3%、89.7%和91.6%。下丘脑腹内侧核GABA能神经元活化是异丙酚诱导意识消失的可能机制之一。     

Characterization of the hypothalamic proopiomelanocortin gene and beta-endorphin expression in the hypothalamic arcuate nucleus of mice elicited by inflammatory pain

We examined proopiomelanocortin (POMC) mRNA and beta-endorphin expression in the hypothalamus of mice after various nociceptive stimuli. The time-course study (10 min, 30 min, 1 h, 2 h, and 10 h) showed that the POMC mRNA level significantly increases from 1 h after s.c. formalin injection and returns to the control level at 10 h. Intrathecal (i.t.) substance P (SP) injection also increases the hypothalamic POMC mRNA level from 1 h to 10 h. However, i.t. glutamate injection did not affect the hypothalamic POMC gene expression at all time points. We found that the POMC mRNA after s.c. formalin injection was located in the arcuate nucleus of the hypothalamus. In the same manner, beta-endorphin immunoreactivity was also increased in the hypothalamic arcuate nucleus. The expression of phosphorylated extracellular signal-regulated protein kinase 1/2 (pERK1/2), phosphorylated calcium/calmodulin-dependent protein kinase-IIalpha (pCaMK-IIalpha) protein and phosphorylated IkappaB (pIkappaB) protein was increased by s.c. formalin injection at various time points. We also found that increased pERK1/2, pCaMKIIalpha and pIkappaB protein after s.c. formalin injection was mainly located in the arcuate nucleus of hypothalamus in which cells containing beta-endorphin after s.c. formalin injection also express pERK1/2, pCaMK-IIalpha and pIkappaB immunoreactivity. In addition, formalin-induced POMC mRNA expression was significantly reduced by 10 min, pretreatment with i.c.v. PD98059 (mitogen-activated protein kinase (MAPK) pathways inhibitor; 6.6 mug) and KN93 (pCaMK-II inhibitor; 20 mug). In conclusion, POMC mRNA expression in the arcuate nucleus of the hypothalamus was increased by inflammatory pain stimuli, in which pERK1/2, pCaMK-IIalpha and NFkappaB may play an important role in the expression of the hypothalamic POMC gene and beta-endorphin expression.     

Identification of Brain Regions Activated by Sevoflurane and Propofol and Regional Changes in Gene Expression

General anesthetics have different efficacies and side effect incidences based on their mechanism of action. However, detailed comparative studies of anesthetics are incomplete. In this study, target brain regions and gene expression changes in these brain regions were determined for sevoflurane and propofol to understand the mechanisms that cause differences among anesthetics. Rats were anesthetized with sevoflurane or propofol for 1 hr, and brain regions with anesthesia-induced changes in neuronal activity were examined by immunohistochemistry and in situ hybridization for c-Fos. Among the identified target brain regions, gene expression analysis was performed in the habenula, the solitary nucleus and the medial vestibular nucleus from laser microdissected samples. Genes altered by sevoflurane and propofol were different and included genes involved in the incidence of postoperative nausea and vomiting and emergence agitation, such as Egr1 and Gad2. GO enrichment analysis showed that the altered genes tended to be evenly distributed in all functional category. The detailed profiles of target brain regions and induced gene expression changes of sevoflurane and propofol in this study will provide a basis for analyzing the effects of each anesthetic agent and the risk of adverse events.     

Distribution of the rhythm-related genes rPERIOD1, rPERIOD2, and rCLOCK,in the rat brain

High densities of mRNAs for three rhythm-related genes, rPeriod1 (rPer1), rPer2, and rClock, which share high homology in Drosophila and mice, were found in the hypothalamic suprachiasmatic nucleus (SCN). The SCN, however, is not the only brain region that expresses these genes. To understand the distributions and possible physiological roles of these rhythm-related genes, we examined the gene expressions of rPer1, rPer2, and rClock in different brain regions by serial coronal, sagittal, and horizontal brain sections in Sprague-Dawley male rats. Animals were housed in a light-controlled room (lights on from 0600 to 1800 h) and killed at 1000 or 1200 h, which corresponds to Zeitgeber time 4 or 6. Semi-quantitative in situ hybridization with (35)S-riboprobes was used to evaluate mRNA levels. The mRNAs of rPer1, rPer2, and rClock were widely distributed in the rat CNS, including the olfactory bulb, cortex, piriform cortex, SCN, ventromedial hypothalamus, arcuate nucleus, hippocampus, mammillary nucleus, pontine nucleus, superior and inferior colliculus, cerebellum, median eminence/pars tuberalis, pineal gland, and pituitary. The expression patterns of mRNAs for rPer1 and rPer2 were almost identical. In contrast, different expression patterns were observed between rClock and rPer1 or rPer2 in several brain regions, including the hypothalamic supraoptic and suprachiasmatic nuclei, the paraventricular zone of the caudate putamen, the superior olivary nucleus, and anterior and intermediate lobes of the pituitary. These findings suggest that the different expression patterns observed for rPer1, rPer2, and rClock might be due to their different physiological role(s) in those brain regions.