甘薯提取物对谷氨酸所致PC12细胞损伤的保护作用初探

观察甘薯提取物对谷氨酸诱导的PC12细胞损伤的保护作用.将大鼠嗜铬细胞瘤细胞(PC12)分为空白对照组、模型组、甘薯提取物0.1、1.0、10.0 μg/mL低、中、高剂量组和1.0 μmol/L尼莫地平阳性药物对照组,用2.0 mmol/L谷氨酸造成PC12细胞损伤,MTT法测定损伤细胞的存活率,观察其细胞损伤的形态学变化,考察甘薯提取物对谷氨酸所致PC12细胞损伤的保护作用.结果表明甘薯提取物可明显提高谷氨酸诱导的PC12损伤细胞存活率,同时能够明显改善谷氨酸诱导的PC12损伤细胞的细胞形态变化,并呈现剂量相关性,具有一定的神经营养及保护作用.     

绞股蓝皂苷对PC12细胞增殖及细胞损伤模型的保护作用

本文通过采用四氮唑蓝(MTT)比色法检测绞股蓝皂苷对PC12细胞增殖活力的影响,并用低糖低血清、谷氨酸、β淀粉样蛋白(Aβ25~35)诱导PC12细胞制备细胞损伤模型,观察绞股蓝皂苷低(50μg·mL~(-1))、中(200μg·mL~(-1))、高(500μg·mL~(-1))剂量在3种细胞损伤模型中对细胞存活率和胞浆中乳酸脱氢酶(LDH)释放量的影响。结果表明,绞股蓝皂苷能显著提高正常PC12细胞的存活率,并能有效对抗低糖低血清、谷氨酸、β淀粉样蛋白引起的细胞凋亡,降低胞浆中乳酸脱氢酶(LDH)的释放量。     

干鲜人参对PC12细胞损伤保护作用的比较研究

分别建立皮质酮、谷氨酸、过氧化氢诱导PC12细胞损伤模型,通过MTT和LDH测定,比较不同浓度的干、鲜人参水提液对于皮质酮、谷氨酸、过氧化氢诱导PC12细胞损伤的保护作用。结果表明皮质酮浓度为200μmol/L、谷氨酸浓度为30 mmol/L和过氧化氢浓度为150μmol/L时,PC12细胞的存活率分别为:53.42%、49.64%、54.27%,当PC12细胞与不同浓度人参提取液共同孵育24 h,再分别加入200μmol/L的皮质酮和150μmol/L的过氧化氢时,与模型组相比,细胞存活率明显提高,乳酸脱氢酶的释放明显减少(P0.01);并且在中、高剂量组,鲜人参组的细胞存活率明显高于干人参组(P0.01),乳酸脱氢酶释放明显低于干人参组(P0.01);但对谷氨酸诱导的PC12细胞损伤则无上述效果。干、鲜人参水提液对于皮质酮、过氧化氢诱导损伤的PC12细胞均有明显的保护作用;在中、高剂量时,鲜人参水提液对细胞保护活性明显好于干人参组,且组间表现出显著性差异(P0.01),表明鲜人参较干人参具有更好的细胞保护活性。干、鲜人参水提液对谷氨酸诱导损伤的PC12细胞却无保护活性。     

芜菁中性多糖对PC12细胞氧化损伤保护作用机制的初步研究CSCD

以H_(2)O_(2)诱导PC12细胞建立氧化损伤模型,研究芜菁中性多糖(neutral polysaccharide from Brassica rapa L.,BRNP)对PC12细胞氧化损伤保护及初步作用机制。采用CCK-8法检测细胞存活率;乳酸脱氢酶(LDH)检测H_(2)O_(2)对PC12细胞氧化损伤的保护作用;JC-1法检测BRNP对H_(2)O_(2)诱导的PC12细胞线粒体膜电位的影响;Western blot法检测BRNP对H_(2)O_(2)诱导的PC12细胞Bax、Bcl-2和Caspase-3蛋白表达水平。结果表明,BRNP对PC12细胞无明显细胞毒性;H_(2)O_(2)的造模浓度和时间分别为300μmol/L、4 h;BRNP在一定程度上可减轻H_(2)O_(2)对PC12细胞的氧化损伤;BRNP可降低H_(2)O_(2)对PC12细胞线粒体膜电位的损伤;以不同剂量BRNP干预PC12细胞后,Bax、Caspase-3蛋白表达水平均有显著降低(P<0.05);而Bcl-2蛋白表达水平显著升高(P<0.05)。综上所述,BRNP能够改善H_(2)O_(2)诱导的PC12细胞氧化应激损伤及保护其细胞功能,其作用机制可能与抑制细胞内LDH生成、提高抗氧化酶活性及其凋亡蛋白表达水平有关。     

RUNX1对氧糖剥夺诱导PC12细胞凋亡的保护作用研究

目的:研究RUNX1在PC12细胞氧糖剥夺模型中的表达及其对PC12细胞的保护作用,并探讨其相关机制。方法:体外培养PC12细胞并构建氧糖剥夺模型,将细胞分为对照组、氧糖剥夺组、RUNX1 si RNA处理组、si RNA对照处理组(sicontrol)、pc DNA3.1-RUNX1处理组(pc RUNX1)和pc DNA3.1对照处理组(pc DNA 3.1)。q RT-PCR和western blot检测RUNX1、磷酸化Akt(p-Akt)和总Akt(t-Akt)表达水平;MTT法检测细胞存活率;Annexin V-FITC/PI双染法检测细胞凋亡。结果:与对照组比较,RUNX1在PC12细胞氧糖剥夺模型中表达水平显著升高;沉默RUNX1可下调PC12细胞的存活率,促进细胞的凋亡,有效抑制p-Akt蛋白表达,而过表达RUNX1显著提高细胞存活率,抑制细胞凋亡,并上调p-Akt蛋白表达;此外,PI3K/Akt通路抑制剂LY294002明显抑制RUNX1过表达对细胞存活率的促进作用和对细胞凋亡的抑制作用。结论:RUNX1可通过PI3K/Akt信号通路保护OGD对PC12细胞的损伤作用。     

沉默lncRNA PCAT1调控miR-128表达增强肺癌H1299细胞放射敏感性

[目的]探讨LncRNA PCAT1调控miR-128对肺癌H1299细胞放射敏感性的影响。[方法]用LncRNA PCAT1阻断剂处理或不处理肺癌H1299细胞,根据放射剂量的不同将细胞分为空白对照组(0Gy)、低剂量组(2Gy)、中剂量组(4Gy)和高剂量组(8Gy)。采用RT-qPCR检测各组细胞LncRNA PCAT1、miR-128表达水平,CCK-8法检测细胞存活率,transwell实验检测细胞侵袭力,划痕实验检测细胞迁移力,流式细胞术检测细胞凋亡率。[结果]空白对照组及各放射剂量组肺癌H1299细胞使用阻断剂后LncRNA PCAT1表达显著降低,miR-128显著升高(P<0.05)。与空白对照组比较,低、中、高剂量组肺癌H1299细胞存活率、迁移率和侵袭力显著降低,凋亡率显著升高(P<0.05)。使用阻断剂后各剂量组细胞存活率、迁移率和侵袭力均显著降低,凋亡率显著升高(P<0.05)。[结论]沉默lncRNA PCAT1可上调miR-128表达来增强肺癌H1299细胞的放射敏感性。     

益智仁对谷氨酸损伤的大鼠离体培养皮层神经元的保护作用研究

目的:通过观察单味中药(益智仁)对离体培养的大鼠皮层神经元谷氨酸损伤模型的保护作用,探讨中药益智仁益智作用的机理,以初步论证中药益智仁对人体的益智效果.方法:利用原代离体培养的大鼠皮层神经元,分为6组:空白对照组,损伤模型组,阳性对照组,益智仁高剂量组,益智仁中剂量组,益智仁低剂量组,制备离体培养皮层神经元的谷氨酸损伤模型,采用MTT法测定细胞存活率,并测定LDH漏出率.结果:MTT法检测结果显示,与空白对照组相比,损伤模型组皮层神经元OD值显著降低(P＜0.05);与损伤模型组相比,各治疗组皮层神经元OD值显著升高(P＜0.05).LDH漏出率检测结果显示,与空白对照组相比,损伤模型组皮层神经元LDH漏出率显著升高(P＜o.05);与损伤模型组相比,益智仁中、高剂量组皮层神经元LDH漏出率显著降低(P＜0.05);其他组皮层神经元与损伤模型组相比,LDH漏出率无显著性差异(P＞0.05).结论:益智仁能够有效的降低细胞的死亡,提示其对线粒体功能具有保护作用,并对初期和后期损伤细胞均有保护作用,但具体作用靶点还需后续实验进一步研究.     

川芎嗪对Aβ25-35诱导体外大鼠海马神经元细胞凋亡的影响

本文通过Aβ25-35诱导体外原代培养的SD乳大鼠海马神经元,建立Aβ毒性损伤细胞模型,结合AnnexinV-FITC/PI荧光双染法流式细胞术、MTT比色法、实时荧光定量PCR及Western blot方法检测川芎嗪(tetrameth-ylpyrazine,TMP)对原代培养的海马神经元细胞活性、早期凋亡率和Bax、Bcl-2基因表达的影响。结果显示川芎嗪高、中剂量可明显增强细胞活性,增加神经元细胞的存活率(P<0.01),可显著抑制海马神经元细胞早期凋亡(P<0.01),抑制凋亡蛋白Bax的表达(P<0.01),增强抗凋亡蛋白bcl-2的表达(P<0.01)。川芎嗪可通过调节Bax/Bcl-2平衡抵抗Aβ25-35诱导的海马神经元凋亡,降低Aβ的神经元毒性,对海马神经元损伤有明显的保护作用。     

黄芪甲苷对高剂量S-氯胺酮诱导PC12细胞损伤的保护作用

以高剂量S-氯胺酮(S-ketamine, SK)诱导PC12细胞构建体外神经损伤模型,探究黄芪甲苷(astragaloside IV,ASⅣ)对高剂量SK诱导PC12细胞损伤的保护作用及其机制。采用CCK-8法测定细胞活力,并以此确定SK的最佳造模浓度和ASⅣ的最佳治疗浓度;流式细胞术测定细胞凋亡率;DCFH-DA荧光探针法检测细胞内活性氧(ROS)的含量;qPCR法检测目的基因的表达;Western blot技术检测目的蛋白的表达。结果显示,SK的最佳造模浓度为450μg/mL,ASⅣ的最佳治疗浓度为25μmol/L;与对照组相比,SK组细胞凋亡率、ROS含量、Caspase-9和Cytochrome C mRNA表达水平均显著升高(P<0.05),Bax、Pro-Caspase-9、Cleaved-Caspase-9和Cytochrome C蛋白表达量同样显著上升(P<0.05),而Bcl-2/Bax mRNA表达水平比值、Bcl-2蛋白表达量显著下降(P<0.05);ASⅣ治疗后,明显逆转了高剂量SK诱导引起的各项指标变化(P<0.05)。这说明黄芪甲苷...     

不同浓度白花丹素对骨肉瘤细胞MG-63凋亡迁移、基质金属蛋白酶及Bcl-2、Bax、Ezrin蛋白表达的影响

目的:研究不同浓度白花丹素对骨肉瘤细胞MG-63凋亡迁移、基质金属蛋白酶(MMP)及Bcl-2、Bax、Ezrin蛋白表达的影响。方法:取对数生长期的骨肉瘤MG-63细胞,传代培养成细胞株后以随机法分成对照组、低剂量组、中剂量组、高剂量组。其中对照组加入到0.1%浓度的DMSO完全培养基中培养,低剂量组、中剂量组、高剂量组分别加入到浓度为5、10、20μmol/L的白花丹素的有关培养基中培养。培养24 h后,采用Transwell法检测MG-63细胞迁移率、Hoechst33342染色法检测MG-63细胞凋亡率、Western blot法检测四组MG-63细胞的MMP-2、MMP-9、Bcl-2、Bax、Ezrin蛋白表达水平。结果:培养24 h后,低剂量组、中剂量组、高剂量组的骨肉瘤细胞MG-63凋亡率及Bax蛋白表达水平均较对照组升高(P<0.05),且随白花丹素浓度的增加而升高(P<0.05);骨肉瘤细胞MG-63的细胞迁移率、MMP-2、MMP-9、Bcl-2及Ezrin蛋白表达水平较对照组降低(P<0.05),且随白花丹素浓度的增加而降低(P<0.05)。结论:白花丹素对骨肉瘤细胞MG-63凋亡的促进作用以及迁移的抑制作用明显,其作用机制可能与抑制骨肉瘤细胞MG-63中的MMP-2、MMP-9、Bcl-2、Ezrin蛋白表达及促进Bax蛋白表达有关,且浓度越高,抑制或促进作用越明显。     

mTOR／STAT3信号通路在谷氨酸诱导的PC12细胞损伤中的作用

目的：研究谷氨酸（glutamate,GIu）诱导PCI2细胞损伤后mTOR／STAT3信号通路的表达情况及对细胞损伤的保护作用。方法：用不同浓度谷氨酸作用不同时间诱导PCI2细胞损伤,筛选出合适的浓度和作用时间后,将细胞分为3组进行下一步实验,分别为A组：正常对照组;B组：20mmol／L谷氨酸处理组;C组：20mmol／L谷氨酸＋800nmol／L雷帕霉素（rapamycin,RAPA）处理组。应用流式细胞术检测各组处理12h后细胞凋亡率,Westernblot观察各组处理1h、4h、8h、12h后,P-mTOR,P-STAT3蛋白表达情况。结果：（1）谷氨酸对PCI2细胞的生长抑制作用随作用时间和作用浓度的增加而增强。（2）C组凋亡率明显高于A组和B组。（3）Westernblot检测结果表明B组各时间点p-mTOR,P．STAT3表达均高于A、c组,并在4h时达到高峰。结论：细胞损伤激活了mTOR／STAT3信号通路,该通路的激活减少了细胞凋亡,对谷氨酸导致的神经细胞损伤具有保护作用,有助于神经损伤的修复。     

Antioxidant activity of phenylethanoid glycosides on glutamate-induced neurotoxicity

ABSTRACT

Exposure of PC12 cells to 10 mM glutamate caused significant viability loss, cell apoptosis, decreased activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as increased levels of malondialdehyde (MDA). In parallel, glutamate significantly increased the intracellular levels of ROS and intracellular calcium. However, pretreatment of the cells with acteoside and isoacteoside significantly suppressed glutamate-induced cellular events. Moreover, acteoside and isoacteoside reduced the glutamate-induced increase of caspase-3 activity and also ameliorated the glutamate-induced Bcl-2/Bax ratio reduction in PC12 cells. Furthermore, acteoside and isoacteoside significantly inhibited glutamate-induced DNA damage. In the mouse model, acteoside significantly attenuated cognitive deficits in the Y maze test and attenuated neuronal damage of the hippocampal CA1 regions induced by glutamate. These data indicated that acteoside and isoacteoside play neuroprotective effects through anti-oxidative stress, anti-apoptosis, and maintenance of steady intracellular calcium.     

Effect of nitrendipine on cardiac and renal lesions and arterial hypertrophy

A low dose of nitrendipine (1 mg/kg twice daily) ameliorated the percent incidence and severity of vascular lesions in the kidney and heart induced by deoxycorticosterone (DOC). Less protection was offered by administration of 1 mg/kg of the calcium antagonist once daily. A lower dose of the antagonist (0.5 mg/kg) administered twice daily produced almost no protection against myocardial scars, but the percent incidence and severity of renal tubular casts and glomerular changes were similar to those following injection of 1 mg/kg of the antagonist twice daily. DOC induced hypertrophy of the media in aorta, coronary artery and renal interlobular artery and renal arteriole. Neither 1 mg/kg once or twice daily nor 0.5 mg twice daily of calcium antagonist modified the hypertrophy of the arterial vasculature in the hypertensive DOC group. We conclude that a low dose of the calcium antagonist dissociates at least in part lesions but not hypertrophy from the increased systolic blood pressure, because the antagonist protects against vascular lesions induced by the hypertension. The antagonist likely acts on the endothelial cell of the vessels alone or combined with an effect on the vascular smooth muscle cells.     

Effect of nitrendipine on cardiac and renal lesions and arterial hypertrophy. Protective effect of a low dose of calcium antagonist in deoxycorticosterone-induced hypertensive rats

A low dose of nitrendipine (1 mg/kg twice daily) ameliorated the percent incidence and severity of vascular lesions in the kidney and heart induced by deoxycorticosterone (DOC). Less protection was offered by administration of 1 mg/kg of the calcium antagonist once daily. A lower dose of the antagonist (0.5 mg/kg) administered twice daily produced almost no protection against myocardial scars, but the percent incidence and severity of renal tubular casts and glomerular changes were similar to those following injection of 1 mg/kg of the antagonist twice daily. DOC induced hypertrophy of the media in aorta, coronary artery and renal interlobular artery and renal arteriole. Neither 1 mg/kg once or twice daily nor 0.5 mg twice daily of calcium antagonist modified the hypertrophy of the arterial vasculature in the hypertensive DOC group. We conclude that a low dose of the calcium antagonist dissociates at least in part lesions but not hypertrophy from the increased systolic blood pressure, because the antagonist protects against vascular lesions induced by the hypertension. The antagonist likely acts on the endothelial cell of the vessels alone or combined with an effect on the vascular smooth muscle cells.     

Tyrosine Kinase Activity Is Essential for Interleukin-1β-Stimulated Production of Interleukin-6 in U373 Human Astrocytoma Cells

Abstract: Previous studies have shown that PC12 cells depend on growth factors for their survival. When deprived of growth factors, the cells undergo a dying process termed "apoptosis" (programed cell death). We show here that muscarinic agonists inhibited the apoptotic death of growth factor-deprived PC12M1 cells (PC12 cells stably expressing cloned m1 muscarinic acetylcholine receptors). This protective effect of the muscarinic agonists was observed in both proliferating and neuronal PC12M1 cells, was blocked by the muscarinic antagonist atropine, and was not observed in PC12 cells lacking m1 receptors. Muscarinic receptors therefore mediate inhibition of apoptosis in these cells. In addition to its effect on survival, the muscarinic agonist oxotremorine induced inhibition of DNA synthesis as well as growth arrest of exponentially growing PC12M1 cells at the S and G₂/M phases of the cell cycle. Muscarinic receptors in these cells may therefore mediate inhibition of cell cycle progression.     

The Influence of Lentinan on the Capacity of Repair of DNA Damage and Apoptosis Induced by Paclitaxel in Mouse Bone Marrow Cells

The ability of the flavonoid lentinan (LAN) to enhance the repair of paclitaxel (PAC)‐induced DNA damage and apoptosis in mouse bone marrow cells was investigated. Moreover, the possible mechanism underlying this modulation was determined. LAN was neither genotoxic nor apoptogenic at doses equivalent to 1 or 2 mg/kg/day. Pretreatment of mice with LAN significantly enhances the repair of PAC‐induced DNA damage and bone marrow suppression in a dose dependent manner. Moreover, LAN affords significant protection against PAC‐induced apoptosis. A significant increase of reactive oxygen species and a decrease in reduced glutathione levels were observed after PAC treatment and prior administration of LAN before PAC challenge ameliorated these oxidative stress markers. Conclusively, our study provides, for the first time, that LAN enhances the repair of PAC‐induced DNA damage and apoptosis that resides, at least in part, on its ability to modulate the cellular antioxidant levels and consequently protect bone marrow cells from PAC genotoxicity. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:370‐377, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21499     

Protective Effects of YC-1 Against Glutamate Induced PC12 Cell Apoptosis

Glutamate, one of the major neurotransmitters in the central nervous system, is released into the synaptic spaces and bound to the glutamate receptors which facilitate normal synaptic transmission, synaptic plasticity, and brain development. Past studies have shown that glutamate with high concentration is a potent neurotoxin capable of destroying neurons through many signal pathways. In this research, our main purpose was to determine whether the specific soluble guanylyl cyclase activator YC-1 (3-(5′-hydroxymethyl-2′-furyl)-1-benzyl indazole) had effect on glutamate-induced apoptosis in cultured PC12 cells. The differentiated PC12 cells impaired by glutamate were used as the cell model of excitability, and were exposed to YC-1 or/and ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) with gradient concentrations for 24 h. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl) assay was used to detect the cellular viability. Radioimmunoassay (RIA) was used to detect the cGMP (cyclic guanosine monophosphate) concentrations in PC12 cells. Hoechst 33258 staining and flow cytometric analysis were used to detect the cell apoptosis. The cellular viability was decreased and the apoptotic rate was increased when PC12 cells were treated with glutamate. Cells treated with YC-1 or/and ODQ showed no significant differences in the cell viability and intracellular cGMP levels compared with those of control group. The specific soluble guanylyl cyclase (sGC) inhibitor ODQ showed an inhibitory effect on cGMP level and aggravated the apoptosis of PC12 cells induced by glutamate. YC-1 elevated cGMP level thus decreased PC12 cell apoptosis induced by glutamate, but this effect could be reversed by ODQ. These results revealed that YC-1 might attenuate glutamate-induced PC12 cell apoptosis via a sGC–cGMP involved pathway.     

锰对PC12 细胞的增殖抑制与凋亡研究

目的:研究锰作用下PC12细胞的增殖抑制作用与凋亡相关的形态学、生化指标改变。方法:用200,400,600,800μmol/LMnCl2的培养液,分别作用对数生长期PC12细胞1,2,3,4d后,用MTT筛选锰的细胞毒性剂量;透射电镜观察细胞形态学变化;琼脂糖凝胶电泳检测MnCl2对PC12细胞基因组DNA的影响。结果:MTT实验显示200-800μmol/L MnCl2作用4天对PC12有显著的抑制作用,呈剂量和时间依赖趋势,600μmol/L MnCl2作用4d对PC12的抑制率可达50%以上。600μmol/L MnCl2作用4d电镜可见细胞凋亡,同样条件下细胞DNA碎片化。结论:PC12细胞在锰作用下发生增殖抑制,原因是锰诱导PC12细胞凋亡。     

Neuroprotective effects of ONO-1924H, an inhibitor of poly ADP-ribose polymerase (PARP), on cytotoxicity of PC12 cells and ischemic cerebral damage

N-[3-(4-Oxo-3,4-dihydro-phthalazin-1-yl)phenyl]-4-(morpholin-4-yl) butanamide methanesulfonate monohydrate (ONO-1924H) is a novel inhibitor of poly ADP-ribose polymerase (PARP). In this study, we examined the effects of ONO-1924H on cytotoxicity induced by hydrogen peroxide in PC12 cells in vitro and cerebral damage and neurological deficits induced by middle cerebral artery (MCA) thrombus occlusion in vivo in rat. In the in vitro cytotoxicity assay, exposure to 0.5 mmol/L hydrogen peroxide induced cell death in differentiated PC12 cells. ONO-1924H, a PARP inhibitor (Ki=0.21 micromol/L), reduced cell death in a concentration-dependent manner that was correlated with inhibition of PARP activation. A 50% reduction in cell death (EC50) was achieved with 2.4 micromol/L ONO-1924H. In the MCA occlusion model, ONO-1924H was injected intravenously at doses of 3, 10 and 30 mg/kg/h for 3 h, and cerebral damage and neurological deficits were estimated 24 h after MCA occlusion. ONO-1924H treatment led to a significant decrease in cerebral damage in the 10 mg/kg/h-treated group (P < 0.05) and the 30 mg/kg/h-treated group (P < 0.01). Further, ONO-1924H at doses of 30 mg/kg/h significantly (P < 0.05) improved neurological deficits. These findings suggest that the novel PARP inhibitor, ONO-1924H, affords effective neuroprotection and is a useful therapeutic candidate for the treatment of ischemic stroke.     

Hyperactivity following injection of a glutamate agonist and 6,7-ADTN into rat nucleus accumbens and its inhibition by THIP

The potent glutamate receptor agonist AMPA induced a dose related hyperactivity after bilateral injection of 0.025–0.5 μg into rat nucleus accumbens. The dopamine agonist 6, 7-ADTN (2.5–10 μg) induced a similar effect. The hyperactivity induced by AMPA and 6, 7-ADTN was antagonized by cis-Z-flupentixol (0.31 mg/kg). Reserpine (7.5 mg/kg) plus α-methyltyrosine (200 mg/kg) inhibited AMPA but not 6, 7-ADTN induced motility. Furthermore, AMPA and 6, 7-ADTN induced motility was antagonized by the GABA agonist THIP after systemic administration (5 mg/kg) and intraaccumbens injection (0.125–0.5 μg). The results suggest that glutamatergic mechanisms are important in regulation of locomotor activity by influencing mechanisms afferent to dopamine receptors. Both glutamate and dopamine systems are under inhibitory GABAergic control.