Increased excitatory amino acid transporter 2 levels in basolateral amygdala astrocytes mediate chronic stress–induced anxiety-like behavior

The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.

Excitatory amino acid changes in the brains of rhesus monkeys following selective cerebral deep hypothermia and blood flow occlusion

Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer＇s solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.

Inhibitory and excitatory amino acids in the cerebrospinal fluid of children with two types of cerebral palsy

BACKGROUND： Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE： To investigate differences in the levels of the excitatory amino acids glutamic acid and aspartic acid, and the inhibitory amino acid gamma-aminobutyric acid （GABA） in the cerebrospinal fluid （CSF） of children with spastic cerebral palsy or athetotic cerebral palsy. DESIGN, TIME AND SETTING： Case-control exploratory observation of neurotransmitter in patients. The experiment was performed in the Pediatrics Department of the Second Affiliated Hospital of Changsha Medical College, the Cerebral Palsy Center of Xiangtan Affiliated Hospital of South China University and the Pediatrics Department of Xiangya Hospital, between February 2006 and May 2007. PARTICIPANTS： We selected 27 children with cerebral palsy, including 13 with spastic cerebral palsy and 14 with athetotic cerebral palsy. We selected 10 patients who were not affected by any neurological disease as controls. METHODS： Two mL blood-free CSF was harvested between the third and fourth lumbar vertebrae of each patient after anesthesia, and stored at -70℃. One mL CSF was mixed with 10 mg sulfosalicylic acid and placed in ice-bath for 10 minutes, then centrifuged 2 000 g for 10 minutes. The supernatant was collected for amino acid quantitation. MAIN OUTCOME MEASURES： The concentrations of glutamic acid, aspartic acid and GABA in the CSF were determined by high-performance liquid chromatography and fluorometric method. The correlation of glutamic acid, aspartic acid and GABA levels with muscular tension in children with cerebral palsy was analyzed using linear dependence. RESULTS： The concentration of GABA was significantly lower in both spastic cerebral palsy and athetotic cerebral palsy patients than in the control group （P 〈 0.01）. Glutamic acid and aspartic acid were significantly higher in both cerebral palsy groups than in the control group （P 〈 0.05-0.01）. The concentration of GABA was significantly decreased in spastic cerebral palsy patients compared with the athetotic cerebral palsy group （P 〈 0.05）. Muscular tension was positively correlated with the concentration of glutamic acid in spastic cerebral palsy patients （P 〈 0.05） but there was no significant correlation between aspartic acid or GABA and muscular tension （P 〉 0.05）. CONCLUSION： Spastic cerebral palsy and athetotic cerebral palsy patients exhibit an imbalance of excitatory amino acids and inhibitory amino acids in their CSF： an increase in glutamic acid and aspartic acid, and a decrease in GABA. Amino acid levels are different in the CSF in varied types of cerebral palsy.

The effect of excitatory amino acid transporters 2 on abnormal behavior of offspring influenced by prenatal stress

Aim Prenatal stress （PS） can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat- ed to the occurrence of this phenomenon. Furthermore, recent study has demonstrated that the expression levels of excitatory amino acid transporters 2 （EAAT2） in different brain regions of 1 month PS offspring rats have changed. Methods The SD pregnant rats were used restraint stress to imitate PS from gestation 14 -~ 19 days. Offspring rats were weaned 21 days after birth. The expression of EAAT2 of hippocampus was observed by Western blot. Results The expression of EAAT2 of 1 month PS offspring rats was significantly decreased in comparison to control group. However, the expression of EAAT2 of 2 month PS offspring rats was significantly increased in comparison to 1 month PS offspring rats. Conclusion These phenomena have illustrated that the expression of EAAT2 of PS off- spring rats could show time dependence or reversibility. The expression of EAAT2 may play an important role in the development of mental illness of offspring rats influenced by PS.

Clinical observation on the changes in excitatory amino acids content in cerebrospinal fluid following acute spinal cord injury

To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalfluid (CSF) of 26 patients with acute spinal cord injury by amino acids autoanalyzer. The results showed that con-tent of glutanlate and aspartate was renlarkably elevated in 24 h after trauma and was related to the seventy of injury. The more severe the spinal cord injured, the more remarkable the content of Asp and Gin in CSF increased.The more pronounced the content of EAA in CSF increased, the worse the patient’s prognosis was. Content of EAA in CSF after spinal cord injury may be an indicator to judge injury extent and prognosis. and provide further support for a potential pathophysiological role of EAA in spinal cord injury.

Effects of Nerve Growth Factor on Excitatory Amino Acid Content in Spinal Cord Neuron after Spinal Cord Injury

To investigate the protective mechanism of nerve growth factor (NGF) on spinal cord injury (SCI), surgical spinal cord injury in Wistar rats was performed by a 10 g2.5 cm impact on the posterior spinal cord at T8 level, and a thin plastic tube was placed in subarachoid space below the injury level for perfusion of solution. To the experimental animals were given 60 g (20 l liquid) NGF, purified from bovine seminal plasma, at the moment of injury and 1,2,3,4,8,12,24 h after injury. An equal volume of normal saline was given to rats of the control group at the same time. In the expermental group, the injured spinal cord tissue was taken following treatment. The contents of the excitatory amino acids (Glu, Asp) were determined by high performance liquid chromatography (HPLC). Excitatory amino acid contents in the injured spinal cord were significantly increased at 10 min and 8 h after the injury as compared with those in the control group. However, The peak values of the excitatory amino acid contents in NGF group were obviously lowered. NGF might protect spinal cord against injury in vivo. One of the possible mechanisms is that NGF prohibits neurotoxicity of the exitatory amino acids.

Alteration of Excitatory Amino Acid in Experimen-tal Spinal Cord Injury in Rats

Objective To detect the effect of excitatory ammo add (EAA) in the secondary damage following spinal cord injury (SCI). Methods Glutamate (Glu) and Aspartate (Asp) on the injury site (T8) were studied using a rat SCI model induced by Allen's weight drop method (10g×2. 5cm). The result suggested that Asp and Glu were significantly increased in 10 mm. Results Glu was significantly decreased from 2 h to 24 h,while Asp was a tittle reduced in 2 h,and slightly rose in 4 h as compared with Control Group. Though elevated in 8 h,it dropped again in 24h as compared with Control Group. Conclusion The result indicates that the rise of EAA following SCI could be the cause of the secondary spinal cord damage.

Effect of topiramate on partial excitatory amino acids in hippocampal dentate gyrus of rats after alcohol withdrawal

BACKGROUND： Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE： To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN ： A randomized control animal experiment SETTING ： Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS： Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS： The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups： control group （n=10）, alcohol group （n=10） and topiramate-treated group （n=10）. Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol （10 mL/kg）, once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy （HPLC） respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES ： ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS： Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group （10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01）. In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol （6.06±0.82, 3.50±0.92, P 〈 0.05）, and the withdrawal scores at 48 and 72 hours were close to those in the control group （4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05）.② Changes of the contents of glutamic acid in hippocampal dentate gyrus： In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [（143.32±11.42）%, （99.12±0.69）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（78.50±16.40）%, （99.12±0.69）%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.30±0.37）%, （118.91±10.40）%, （99.55±12.81）%, （99.08±11.42）%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus： In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [（126.60±8.67）%, （129.17±10.40）%, （99.25±0.87）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（89.87±9.93）%, （99.25±0.87）%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.27±0.32）%, （120.81 ±12.63）%, （98.91±7.83）%, （85.92±8.07）%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. CONCLUSION： ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.

Protective Effect of Tetrandrine against Excitatory Amino Acids induced Neuronal Injury in Cortical Culture

The ability of tetrandrine (Tet), an alkaloid isolated from Radix Stephaniae Tetrandrae, to reduce cortical neuronal injury in cortical cultures derived from fetal rats was quantitatively assessed by examination of morphological changes and measurement of lactate dehydrogenase (LDH) released to the extracellular bathing media Cell cultures exposed to the excitatory amino acids (EAA) 50 μmol L 1 glutamate (Glu), 20 μmol L 1 N methyl D aspartate (NMDA), 300 μmol·L 1 β N oxalylamino L alanine (BMAA, NMDA receptor agonist) or 20 μmol·L 1 β N oxaly lamino L alanine (BOAA, non NMDA receptor agonist) for 24 h at 37℃ showed widespread neuronal injury Tet had little effect on the injury induced by 20 μmol·L 1 NMDA but 10 7 and 10 6 μmol·L 1 Tet did partially attenuate the neuronal degeneration, neuronal loss and LDH efflux resulting from prolonged exposures to 100 μmol·L 1 Glu, 300 μmol·L 1 BMAA and 20 μmol·L 1 BOAA respectively The ability of Tet to reduce the neuronal injury induced by prolonged exposure to EAA may contribute, at least in part, to the reduction of Ca 2+ influx through inhibiting the opening of voltagegated Ca 2+ channels Another mechanism that Tet might have a little inhibitory effect on NMDA receptor on neuronal membrane cannot be excluded, as BMAA has been considered to act as a weak NMDA receptor agonist

Excitatory amino acid transporter supports inflammatory macrophageresponses

Excitatory amino acid transporters(EAATs) are responsible for excitatory amino acid transportation and are associated with auto-immune diseases in the central nervous system and peripheral tissues.However, the subcellular location and function of EAAT2 in macrophages are still obscure. In this study,we demonstrated that LPS stimulation increases expression of EAAT2(coded by Slc1a2) via NF-κB signaling. EAAT2 is necessary for inflammatory macrophage polarization through sustaining mTORC1 activation. Mechanistically, lysosomal EAAT2 mediates lysosomal glutamate and aspartate efflux to maintain V-ATPase activation, which sustains macropinocytosis and mTORC1. We also found that mice with myeloid depletion of Slc1a2 show alleviated inflammatory responses in LPS-induced systemic inflammation and high-fat diet induced obesity. Notably, patients with type Ⅱ diabetes(T2D) have a higher level of expression of lysosomal EAAT2 and activation of mTORC1 in blood macrophages. Taken together, our study links the subcellular location of amino acid transporters with the fate decision of immune cells,which provides potential therapeutic targets for the treatment of inflammatory diseases.

Effect of Diazepam on the Contents of Amino Acids and Free Radical during Ischemia/Reperfusion Injury

The protective effect and mechanism of diazepam on ischemia neurons during cerebral ischemia and reperfusion were studied. Sixty three Wistar rats were divided randomly into nine groups: control group , ischemia groups including subgroups of is3h, is3 h/rep1 h, is3 h/rep2 h, is3 h/rep3 h, diazepam treated groups , including subgroups of is3 h, is3 h/rep1 h, is3 h/rep2 h, is3 h/rep3 h with Zea longa's animal model of middle cerebral artery occlusion. The comparison between the ischemia group and diazepam treated group showed that diazepam could obviously decrease the production of glutamate, asparate, MDA and increase the synthesis and release of GABA, SOD and GSH PX. It was concluded that diazepam exerted its protective effects on neurons through complex mechanisms of regulating the synthesis and release of excitotary/inhibitory amino acids and free radicals.

基于星型胶质细胞探讨针刺治疗缺血性脑卒中机制的研究进展

星型胶质细胞(AS)作为神经系统中数量最多的神经胶质细胞,与神经、血管及其他胶质细胞联系密切,在缺血性脑卒中的发生发展过程中具有重要的调控作用。针刺疗法具有多靶点、多途径调节的特点。针刺对AS的整体调控作用表现在:抑制AS活化、促进AS增殖与抑制AS过度增生和有利于超微结构的稳定性。本研究以AS为靶点,从针刺促进神经再生与修复、调控兴奋性氨基酸代谢、调节能量代谢、调控血管再生、抑制氧化及炎症反应、调节细胞通讯、抑制脑水肿、促进神经干细胞分化和抑制胶质瘢痕的过度生成等方面总结针刺治疗缺血性脑卒中的相关机制,为发挥针灸治疗优势提供科学依据。

HBV相关肝细胞癌组织GLAST、GS蛋白表达及其与切除术后早期复发转移的关系

目的:检测乙型肝炎病毒(HBV)相关肝细胞癌组织兴奋性氨基酸转运体1(GLAST)、谷氨酰胺合成酶(GS)蛋白表达,并分析其与切除术后早期复发转移的关系。方法:选取本院2020年3月至2022年5月收治的125例实施切除术的HBV相关肝细胞癌患者,采用免疫组化法检测癌组织和切缘正常组织GLAST、GS蛋白表达。比较癌组织与切缘正常组织GLAST、GS蛋白阳性率;比较不同临床病理特征患者癌组织GLAST、GS蛋白阳性率;随访1年,Cox回归分析复发转移的影响因素。结果:癌组织GLAST、GS蛋白阳性率分别为28.57%、73.95%,前者低于切缘正常组织的57.98%,后者高于切缘正常组织的33.61%(P<0.05);HBV感染病程>22年患者癌组织GLAST蛋白阳性率均低于<10年、10~22年患者(P<0.05);肿瘤淋巴结转移(TNM)Ⅲ~Ⅳ期、有门静脉癌栓、未/低分化患者癌组织GLAST蛋白阳性率低于TNMⅠ~Ⅱ期、无门静脉癌栓、中/高分化患者(P<0.05),GS蛋白阳性率趋势相反;术后早期复发转移发生率为21.01%;年龄(HR=1.471,95%CI 1.086~1.993)、伴肝硬化(HR=1.728,95%CI 1.110~2.691)、GLAST蛋白阳性表达(HR=0.451,95%CI 0.224~0.910)、GS蛋白阳性表达(HR=2.255,95%CI 1.027~4.948)均是患者术后早期复发转移的影响因素(P<0.05)。结论:HBV相关肝细胞癌组织GLAST蛋白阳性率降低、GS蛋白阳性率升高,且二者均与切除术后早期复发转移有关。

岗田酸诱导大鼠脑神经细胞表达谷氨酸转运体EAAT1

为研究tau蛋白高度磷酸化与谷氨酸转运体功能之间的关系,实验采用免疫组织化学、荧光双标记技术及大鼠额叶皮质定位注射的方法,观察了蛋白磷酸酶抑制剂岗田酸（okadaic acid,OA）所致神经细胞退化对谷氨酸转运体亚型EAAT1表达的影响。结果如下:（1）在OA注射中心区神经元早期出现胞体固缩、肿胀、核移位,在注射3d时细胞破碎,发生坏死,并有大量炎性细胞浸润等病理现象;边周区细胞呈AT8（微管相关蛋白tau磷酸化指标）免疫阳性反应;（2）OA首先诱导神经细胞突起远端tau蛋白磷酸化,并逐渐向胞体发展,形成营养不良的神经细胞突起和神经纤维缠结样病理改变;（3）AT8免疫阳性反应脑区的神经细胞高表达谷氨酸转运体EAAT1,在12h阳性表达细胞数显著增多（P<0.01）,1d时达峰值（P<0.001）,3d时明显减少。在OA作用下EAAT1表达于星形胶质细胞和神经元。结果提示,OA致微管相关蛋白tau高度磷酸化时可诱导该区星形胶质细胞和神经元高表达谷氨酸转运体EAAT1。EAAT1高表达的病理生理意义有待进一步的阐明。

必需脂肪酸对大鼠脑组织中EAA含量的影响

目的 探讨在大鼠脑发育期补充必需脂肪酸兴奋性氨基酸 (EFA)对脑组织中EAA含量的影响。方法 断乳大鼠 (1个月 ) 3 0只 ,雌雄不拘 ,分为正常组、EFA缺乏组和补充鱼油组 ,分别以不同饲料喂养 3个月 ,取出新鲜的大脑皮层和海马组织 ,测定天门冬氨酸、谷氨酸的含量 ;尼氏染色和嗜银染色观察大脑皮质和海马细胞形态结构的变化。结果 与正常组相比 ,EFA缺乏组的EAA含量均显著升高 (P <0 0 5 ) ,补充鱼油组无明显差异 ;与补充组相比 ,EFA缺乏组大脑皮质大锥体细胞数目明显减少、排列不规则、稀疏、轴突纤维短 ,海马细胞层数较少、体积也较小。结论 发育期EFA缺乏会导致脑组织中EAA含量明显升高 ,神经形态异常。

电针对神经病理性疼痛大鼠的干预作用及其脊髓EAAs含量的影响

目的观察电针对神经病理性疼痛大鼠痛阈的作用以及脊髓兴奋性氨基酸含量的影响,探讨电针治疗神经病理性疼痛的机制。方法SD大鼠随机分为对照组、假模型组和造模组,采用大鼠坐骨神经分支选择性损伤(SNI)模型,造模组SNI术后选取造模成功的大鼠再随机分为模型组、电针组、假电针组。分别于SNI术前、术后第7天及第9天、第6次治疗后测定大鼠的机械痛阈和热痛阈。造模后第10天开始进行电针干预,电针"环跳"与"委中"穴,观察其对大鼠机械痛阈和热痛阈的影响,并通过脊髓微透析技术,应用柱前衍生法+HPLC荧光检测法检测大鼠脊髓兴奋性氨基酸的含量。结果SNI手术可以显著降低大鼠机械痛阈,模型组大鼠脊髓微透析液中Glu和Asp的含量较同时段对照组、假模型组有显著升高(P<0.05);电针组、假电针组脊髓微透析液中Glu和Asp含量与同时段模型组比较明显减少,差异具有统计学意义(P<0.05)(假电针组第2时段Glu除外),并且电针可以显著减轻SNI大鼠的机械痛敏状态。结论电针治疗神经病理性疼痛可能与降低脊髓兴奋性氨基酸含量有关。

吗啡诱导的CPP复燃大鼠前额叶皮层和海马区EAAT3蛋白表达的变化

目的:观察吗啡诱导的条件性位置偏爱(CPP)复燃大鼠前额叶皮层和海马区兴奋性氨基酸转运蛋白3(EAAT3)的表达变化,探讨前脑皮层及海马区EAAT3在阿片类药物复吸过程中的作用。方法:成年雄性SD大鼠40只,随机分为对照组(control)、CPP建立(Es)、消退(Ex)、复燃2 h(Re2)、复燃4 h(Re4)组,每组8只。腹腔注射吗啡(10 mg/kg)连续10 d,建立CPP模型;停止给药使CPP逐渐消退;单次腹腔注射吗啡2.5 mg/kg诱导已消退的CPP复燃。Western blotting检测各组大鼠前额叶皮层和海马区EAAT3蛋白表达变化。结果:(1)腹腔注射恒定剂量的吗啡10 mg/kg,Es组大鼠在伴药箱的停留时间比control组明显延长(P<0.05),成功建立CPP模型;待CPP消退后,吗啡2.5 mg/kg腹腔注射诱发Re2和Re4组大鼠在伴药箱的停留时间再次比control组明显延长(P<0.05),CPP复燃。(2)Es组前额叶皮层EAAT3比control组表达减少(P<0.05),CPP消退的Ex组表达回升,在Re4组表达再次减少(P<0.05)。(3)海马区EAAT3在各组表达水平未见明显变化(P>0.05);而Es、Ex组海马CA1区EAAT3比control组表达明显升高(P<0.05)。结论:吗啡诱导CPP复燃时,前额叶皮层EAAT3的蛋白表达水平降低,重现CPP建立时的变化,提示阿片类药物复吸行为的形成可能与前脑皮层EAAT3的表达减少有关。

胆红素脑病模型豚鼠EAA神经递质的检测

目的 探讨胆红素神经毒性脑组织兴奋性氨基酸（ＥＡＡ） 神经递质变化。方法 制作胆红素脑病动物模型基础上在体脑内微透析，提取神经突触间细胞外液，ＨＰＬＣ 检测分析天门冬氨酸（Ａｓｐ）、谷氨酸（Ｇｌｕ） 、甘氨酸（Ｇｌｙ） 。结果 胆红素毒性脑组织细胞外Ｇｌｙ 较对照组明显升高，而Ａｓｐ 、Ｇｌｕ 与对照组差异不显著。结论 胆红素神经毒性ＮＭＤＡ受体活性变化机制涉及Ｇｌｙ 细胞外堆积，提高ＮＭＤＡ受体对ＮＡＡ 神经递质Ａｓｐ、Ｇｌｕ敏感性。

蝙蝠葛酚性碱对局灶性脑缺血大鼠海马神经细胞谷氨酸转运体EAAC1 mRNA表达的影响

目的探讨蝙蝠葛酚性碱(PAMd)对大鼠局灶性脑缺血后海马神经细胞谷氨酸转运体EAAC1 mRNA表达的影响,及其对脑缺血的保护机制。方法 SD大鼠42只,随机分为假手术组(不给药)、模型对照组(不给药)、PAMd组(灌胃给予PAMd 10 mg·kg-1),每组14只。线栓法制备大鼠局灶性脑缺血模型。采用2,3,5-氯化三苯基四氮唑(TTC)染色检测脑梗死体积,逆转录-聚合酶链反应(RT-PCR)检测海马神经细胞谷氨酸转运体EAAC1 mRNA表达。结果缺血24 h后,假手术组、模型对照组和PAMd组脑梗死比例分别为(0.0±0.0)%,(35.3±2.9)%,(21.3±3.8)%(P<0.05);缺血侧海马EAAC1 mRNA相对表达量分别为0.97±0.04,2.46±0.13,1.91±0.15(P<0.05)。结论 PAMd可能通过下调缺血后EAAC1的表达升高,从而减轻谷氨酸的兴奋毒性作用,发挥对脑缺血的保护作用。

雌二醇对溴氰菊酯染毒胶质细胞EAAs释放影响

目的 以原代培养的神经胶质细胞为研究对象 ,观察溴氰菊酯对胶质细胞兴奋性氨基酸 (EAAs)释放的影响 ,并探讨内分泌激素雌二醇对溴氰菊酯作用的影响。方法 高效液相色谱 (HPLC)检测不同水平 17β -雌二醇(10 -5、10 -8、10 -11mol/L)对 2× 10 -5mol/L溴氰菊酯染毒大鼠原代神经胶质细胞兴奋性氨基酸释放的影响 ,并观察雌激素受体拮抗剂Tamoxifen对雌激素有无拮抗作用。结果 2× 10 -5mol/L溴氰菊酯可增加大鼠原代胶质细胞谷氨酸 (Glu)释放 ,释放增加率为 82 0 3% ;10 -8mol/L17β -雌二醇可部分抑制溴氰菊酯所致Glu释放增加 ,抑制率为37 77% ;Tamoxifen对雌二醇的作用并无干扰。结论 17β