益坤宁对围绝经期大鼠下丘脑雌激素受体表达的影响

目的检测益坤宁对围绝经期大鼠下丘脑雌激素受体（estrogen receptor,ER）表达的影响,探讨益坤宁治疗围绝经期综合征的作用机制。方法采用自然衰老的围绝经期大鼠,随机分为围绝经期对照组、西药对照组和中药实验组;另取5月龄青年雌性大鼠做青年对照组。各组大鼠分别连续灌胃给予生理盐水、利维爱、中药益坤宁和生理盐水4周。通过免疫组化观察大鼠下丘脑ER蛋白的表达部位;Western blot定量检测大鼠下丘脑ERα和ERβ蛋白表达。结果ERα、ERβ蛋白主要表达于细胞胞质中。围绝经期对照组与青年组相比,ERa、E邓蛋白表达量明显下降（P〈0．05,P〈0．01）;中药实验组与围绝经期对照组比较,ERα、ERB蛋白表达量均明显增多（P〈0．05,P〈0．01）;西药对照组与围绝经期对照组相比,ERα、ERβ蛋白表达量增多（P〈0．05）。结论益坤宁通过提高围绝经期大鼠下丘脑组织中ERα、ERβ蛋白表达水平,使ER的合成增加,从而提高雌激素靶组织中ER的含量以增强雌激素的生物活性而发挥治疗作用。     

一氧化氮促进体外培养大鼠脑室下区神经干细胞的分化

目的：探讨一氧化氮（NO）对新生大鼠体外培养的神经干细胞（NSCs）分化的作用。方法：采用常规方法分离新生大鼠脑室下区（SVZ）组织,进行NSCs体外培养。用DETA／NO作为NO供体,用L-NAME作为一氧化氮合酶（NOS）抑制剂。免疫荧光法检测NSCs标志物-巢蛋白（nestin）、神经元标志物-8Ⅲ型微管蛋白（Tuj-1）和星型胶质细胞标志物-胶质原纤维酸性蛋白（GFAP）的表达,还检测了神经元型NOS的表达。用Greiss还原法检测培养液中总NO的浓度。结果：培养的神经球均为nestin阳性、BIdu阳性和nNOS阳性。NSCs和40μmol／L、50μmol／L、60μmol／LDEFA／N0共培养5d,实验组培养液中N0浓度较对照组显著增高（P〈0．01）,相应实验组分化的神经元数和星型胶质细胞数较对照组明显增加（P〈0．01和P〈0．05）。NSCs和100μmol／L、150μmol／L、200μmol／LL-NAME共培养5d,实验组培养液中NO浓度较对照组降低（P〈0．05）,相应实验组分化的神经元数和星型胶质细胞数也较对照组减少（P〈0．05）。结论：NO能直接促进大鼠SVZ体外培养的NSCs分化。     

蓝莓花色苷预处理对大鼠心肌梗死的保护作用

目的观察蓝莓花色苷（blueberryanthocyanin,BBA）预处理对实验性急性心肌梗死大鼠心肌梗死面积,心肌肌钙蛋白-T（cTn-T）表达,Bax、Bcl-2mRNA表达的影响,探讨其干预心肌梗死的机制。方法40只Wistar大鼠随机分为假手术组,心肌梗死模型组,BBA低、中、高剂量组,药物干预4周,末次给药30min后结扎左冠状动脉前降支建立心梗动物模型。24h后,TTC检测心肌梗死面积;Westernblotting方法检测心肌细胞cTn-T蛋白表达;realtimePCR方法检测Bcl-2mRNA、BaxmRNA表达。结果模型组和假手术组相比,模型组心肌梗死面积显著升高（P〈0．01）,心肌细胞cTn．T蛋白表达下降（P〈0．05）,Bcl-2mRNA表达下降（P〈0．05）,BaxmRNA表达显著升高（P〈0．01）,Bcl-2／Bax比值显著降低（P〈0．01）。BBA干预给药组和模型组相比,中剂量组心肌梗死面积低于模型组（P〈0．05）,低剂量组心肌细胞cTn-T蛋白表达升高（P〈0．05）,中剂量组Bcl-2mRNA表达升高（P〈0．05）,低、中剂量组BaxmRNA表达下降（P〈0．05）,中剂量组Bcl-2／Bax比值升高（P〈0．05）。结论蓝莓花色苷对心肌梗死后心肌细胞具有明确的保护作用,其机制可能与减少心肌梗死面积,上调心肌细胞eTn-T蛋白的表达,上调Bcl-2mRNA表达、下调BaxmRNA表达,抑制心肌梗死后心肌细胞凋亡有关。     

听源性遗传癫痫易感大鼠大脑皮层胆囊收缩素mRNA的原位杂交检测

本实验用原位杂交法,对听源性遗传癫痫易感大鼠（P77PMC)癫痫发作前,单次癫痫发作和多次发作时大脑颞皮层CCK mRNA阳性信号进行了检测,结果显示：（1）单次和多次癫痫发作后颞皮层CCK mRNA阳性神经元数量明显增加（P＜0．01）;（2）多次癫痫发作者上述脑区CCK mRNA阳性神经元数量较单次癫痫发作有明显的下降（P＜0．01）,大脑颞皮层CCK mRNA增高表明,CCK mRNA在癫痫发作过程中起了某种作用,多次癫痫发作大鼠CCK mRNA表达降低提示,单次和多次癫痫发作时大脑皮层CCK mRNAl转录的调控可能存在不同的机制。     

壳聚糖纳米基因载体介导IL-10和HGF基因重组体在大鼠活体肝移植中的研究

目的：研究hIL-10和HGF重组体对大鼠活体肝移植术后急性排斥反应的抑制作用。方法：以DA大鼠（RT1a）为供体．Lewis大鼠（RT11）为受体建立异种肝移植鼠模型,实验组于移植后1天及7天,腹腔内注射T—HGF和T-hIL-10重组体（100μg／ml）100μl,对照组注射等量生理盐水。移植后1,7,10,20天取大鼠尾静脉血,ELISA法测定血清HGF、IL-10水平,RT-PCR测定肝细胞HGF、IL-10m RNA的表达水平,常规肝功能测定,活体肝移植动物生存期观测。结果：实验组鼠肝细胞有HGF和IL-10 mRNA表达,对照组肝细胞未见表达。对照组大鼠HGF和IL-10水平一直维持在较低水平,实验组大鼠HGF和IL-10水平明显高于对照组（P〈0．05）。注射重组体的实验组平均生存时间为（19±0．9）天,20天时存活只数为6只,存活率75％;对照组平均生存时间为（8．6±0．5）天,20天时存活只数为2只,存活率75％（P〈0．05）。对照组未注射重组体,ALT和AST值持续升高,注射重组体后ALT和AST值亦有升高,但明显低于对照组（p〈0．05）。结论：活体肝移植大鼠导入IL—10和HGF基因重组体后可抑制移植术后急性排斥反应．     

基于NR2B基因探讨疏肝与补肾法对吗啡精神依赖的调节作用及机制

目的：探讨补肾法与舒肝法对大鼠吗啡精神依赖的调节作用及机制。方法：使用盐酸吗啡建立大鼠精神依赖模型（conditioned place preference,CPP）,采用Obersiver5．0行为学软件分析大鼠的CPP效应,并利用RealtimePCR方法测定伏核和前额叶皮质内NR2B亚基的mRNA含量。结果：与对照组相比,模型组大鼠在白侧累积停留时间极显著长于对照组（P〈0．01）,同时伏核与前额叶皮质中NR2B的mRNA水平也显著升高（P〈0．01和P〈0．05）;与模型组相比,补肾组和舒肝组大鼠在白侧的累积停留时间显著下调（P〈0．05）,疏肝组NR2B的mRNA也显著下降（P〈0．05）,而补肾组变化不显著。结论：①补肾法与舒肝法对吗啡引起的精神依赖均有调节作用。②舒肝法的作用机制可能在于通过影响伏核和前额叶皮质中NR2B亚基的mRNA表达进一步调节精神依赖的相关神经通路。③补肾法的作用机制与NR2B亚基的mRNA表达关系不密切,其调节的具体机制尚有待研究。     

TLR4在四氯化碳诱导的肝硬化大鼠骨髓血窦内皮细胞的表达

目的：检测Toll样受体4（TLR4）在四氯化碳诱导的肝硬化大鼠骨髓血窦内皮细胞的表达,为进一步研究肝硬化时骨髓损伤的发生机制提供实验依据。方法：选择Wistar大鼠给予腹腔注射CCl4,一周两次,建立肝硬化大鼠模型。分别于建模8周和12周检测大鼠血浆内毒素的水平,免疫组化检测大鼠骨髓血窦内皮细胞上TLR4的表达情况,RT-PCR测定骨髓组织中TLR4mRNA的表达,分析TLR4的表达与内毒素血症间的关系。结果：给予CCl4 8周和12周时,对照组大鼠血浆内毒素水平分别为（0．216±0．024）Eu／ml和（0．133±0．022）Eu／ml,模型组大鼠血浆内毒素水平分别为（0．626±0．021）Eu／ml和（0．725±0．031）Eu／ml,分别较对照组显著升高,差异均有统计学意义（P〈0．001）;骨髓血窦内皮细胞TLR4蛋白表达及骨髓组织中TLR4mRNA的表达均显著高于对照组,差异均有统计学意义（P〈0．05）。大鼠骨髓TLR4蛋白和mRNA表达与血浆内毒素水平均呈显著正相关（r=0．841,0．803,P均〈0．001）。结论：CCl4诱导的肝硬化大鼠骨髓血窦内皮细胞TLR4表达升高,并伴随大鼠内毒素血症的发生,提示肝硬化时肠源性内毒素血症可能参与了骨髓的造血功能的损害和病变。     

戊四氮致痫大鼠情感反应、学习记忆功能及海马N-甲基-D-门冬氨酸受体mRNA表达的改变

目的：探讨实验性癫痫持续状态（SE）对大鼠认知功能的影响及N-甲基-D-门冬氨酸（NMDA）受体表达的变化。方法：戊四氮诱导大鼠SE,采用抬高迷宫和Morris水迷宫观察大鼠情感反应和学习记忆功能的改变。RT-PCR方法检测大鼠海马NMDA受体亚单位NR1mRNA的表达。结果：sE组大鼠在抬高迷宫开放臂中逃避时间延长（P〈0．01）,进入次数增多（P〈0、01）;水迷宫中逃避潜伏期延长（P〈0.01）,搜寻策略变差（P〈0．05）,平台象限游泳时间百分比降低（P〈0．01）,穿越平台次数减少（P〈0．01）。同时伴有海马NR1mRNA表达下调（P〈0．01）。结论：SE可使大鼠情感行为改变和学习记忆功能受损,NR1可能参与这一变化的病理生理过程。     

p-ERK1／2及ERK2mRNA在哮喘大鼠气道中的表达变化

目的探讨细胞外信号调节激酶在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响。观察细胞外信号调节激酶是否参与了哮喘气道重构这一病理过程。方法18只6周龄雄性wistar大鼠随机分为对照组、哮喘组、地塞米松干预组各6只。以腹腔注射10％卵蛋白和1％卵蛋白雾化吸入复制慢性哮喘模型。干预组在每次激发前给予地塞米松干预。用免疫组化与原位杂交法检测p-ERK1／2及ERK2mRNA在不同大鼠肺组织的表达程度,采用图像分析系统进行图象分析。结果（1）哮喘模型组气道壁面积和平滑肌厚度较对照组和干预组显著增加（P〈0．05）。（2）哮喘组p-ERK1／2及ERK2mRNA在大鼠肺组织的表达程度较对照组和干预组显著增加（P〈0．05）。（3）直线相关性分析显示,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中p-ERK1／2表达水平呈正相关（分别为r=0．858,r=0．848,P均〈0．05）,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中ERK2mRNA表达水平呈正相关,（分别为r=0．918,r=0．860,P均〈0．05）。结论哮喘大鼠肺组织p-ERK1／2及ERK2mRNA表达上调,并与气道重构密切相关,该结果提示细胞外信号调节激酶可能参与了气道重构中平滑肌的增殖过程。     

电针不同穴位对慢性炎症痛模型大鼠心理行为改变的实验观察

目的：观察电针不同穴位对慢性炎症痛模型大鼠行为学改变的影响,进一步探讨电针对慢性痛所致心理行为改变的调节规律：方法：将40只雄性Wistar大鼠随机分为正常组、模型组、电针百会组、电针关元组、电针足三里组,每组各8只。除正常组外,其余各组均采用弗氏完全佐剂（CFA）制备佐剂性关节炎（AA,即慢性炎症痛）大鼠模型,于造模第2天各治疗组捆绑固定后给予电针20min,正常组及模型组捆绑束缚20min,隔日一次,共10次。于造模前、造模后、治疗5次、10次分别采用高架十字迷宫检测各组大鼠开放臂进入次数比例（OE％）及开放臂停留时间比例（OT％）的变化。结果：与造模前比较,电针百会穴组大鼠造模后0E％和0T％明显减少（P〈0．05,P〈0．05）,且治疗5次后OT％、治疗10次后0E％与0T％均降低明显（P〈0．01,P〈0．01,P〈0．05）,而电针关元组大鼠治疗10次后OE％和OT％则明显升高（P〈0．05,P〈0．05）,电针足三里组大鼠造模后0T％、治疗5次后大鼠OE％与OT％、治疗10次后OT％均明显降低（P〈O．01,P〈0．05,P〈0．01,P〈0．05）;与造模刚结束比较,电针百会组大鼠在治疗5次、10次后0E％由升高逐步降低,而OT％由低逐渐升高（P〉0．05）,电针关元组模型大鼠治疗10次后模型大鼠0E％和0T％均明显升高（P〈0．05,P〈0．05）,电针足三里组模型大鼠治疗10次后OT％升高明显（P〈0．05）;与治疗5次后比较,电针百会组大鼠在治疗10次后OE％降低、OT％升高（P〉O．05）,电针关元组与电针足三里组大鼠治疗10次后OE％和OT％均明显升高（P〈0．05,P〈0．05;P〈0．01,P〈0．01）。与电针百会组比较,电针关元组与电针足三里组大鼠在治疗10次时OE％均明显升高（P〈0．01,P〈0．01）结论：电针不同穴位具有一定抗抑郁和抗焦虑作用,可改善慢性炎症痛所致大鼠焦虑、情绪行为的变化;不同穴位效应不同,关元穴与足三里穴具有综合调节、抗焦虑效应,且具有相对特异性。     

Effect of p-chloroamphetamine on 5-HT1A and 5-HT7 serotonin receptor expression in rat brain

The aim of this study was to investigate if p-chloroamphetamine (PCA), which is neurotoxic to serotonin (5-HT) nerve terminals, was able to induce, like 3,4-methylenedioxymethamphetamine, a region-specific regulation of 5-HT1A receptor mRNA expression. The effect of PCA on the expression of 5-HT7 receptors, which share some pharmacological properties with 5-HT1A receptors, was comparatively studied. PCA (2 x 5 mg/kg) produced a lasting depletion of 5-HT content in the rat frontal cortex and hippocampus. In the hippocampus, the maximal 5-HT depletion was found on day 21 (-70%), whereas in the cortex, the highest 5-HT depletion was found on day 14 (-73%), with a partial but significant recovery on day 21. At the latter time point, 5-HT1A receptor mRNA expression was increased by 80% in the cortex and decreased by 50% in the hippocampus. The 5-HT1A receptor mRNA expression was also enhanced after exposure to PCA of rat cortical but not of hippocampal primary cultures. In regard to 5-HT7 receptor mRNA expression, the most remarkable change after PCA was the great increase (+200%) in the brain-stem. Binding studies to 5-HT1A receptors matched the changes in receptor mRNA expression. Gel shift assays revealed enhanced nuclear protein binding to the KB sequence with use of cortical but not hippocampal extracts of PCA-treated rats. Overall, the data show region-specific changes in 5-HT receptor-type expression that may not be entirely dependent on the neurotoxic effect of PCA on 5-HT terminals.     

Effects of combined treatment with mephedrone and methamphetamine or 3,4-methylenedioxymethamphetamine on serotonin nerve endings of the hippocampus

Aims

Mephedrone is a stimulant drug of abuse with close structural and mechanistic similarities to methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA). Although mephedrone does not damage dopamine nerve endings it increases the neurotoxicity of amphetamine, methamphetamine and MDMA. The effects of mephedrone on serotonin (5HT) nerve endings are not fully understood, with some investigators reporting damage while others conclude it does not. Presently, we investigate if mephedrone given alone or with methamphetamine or MDMA damages 5HT nerve endings of the hippocampus.

Main methods

The status of 5HT nerve endings in the hippocampus of female C57BL mice was assessed through measures of 5HT by HPLC and by immunoblot analysis of serotonin transporter (SERT) and tryptophan hydroxylase 2 (TPH2), selective markers of 5HT nerve endings. Astrocytosis was assessed through measures of glial fibrillary acidic protein (GFAP) (immunoblotting) and microglial activation was determined by histochemical staining with Isolectin B4.

Key findings

Mephedrone alone did not cause persistent reductions in the levels of 5HT, SERT or TPH2. Methamphetamine and MDMA alone caused mild reductions in 5HT but did not change SERT and TPH2 levels. Combined treatment with mephedrone and methamphetamine or MDMA did not change the status of 5HT nerve endings to an extent that was different from either drug alone.

Significance

Mephedrone does not cause toxicity to 5HT nerve endings of the hippocampus. When co-administered with methamphetamine or MDMA, drugs that are often co-abused with mephedrone by humans, toxicity is not increased as is the case for dopamine nerve endings when these drugs are taken together.     

Sex-Dependent Psychoneuroendocrine Effects of THC and MDMA in an Animal Model of Adolescent Drug Consumption

Ecstasy is a drug that is usually consumed by young people at the weekends and frequently, in combination with cannabis. In the present study we have investigated the long-term effects of administering increasing doses of delta-9-tetrahydrocannabinol [THC; 2.5, 5, 10 mg/kg; i.p.] from postnatal day (pnd) 28 to 45, alone and/or in conjunction with 3,4-methylenedioxymethamphetamine [MDMA; two daily doses of 10 mg/kg every 5 days; s.c.] from pnd 30 to 45, in both male and female Wistar rats. When tested one day after the end of the pharmacological treatment (pnd 46), MDMA administration induced a reduction in directed exploration in the holeboard test and an increase in open-arm exploration in an elevated plus maze. In the long-term, cognitive functions in the novel object test were seen to be disrupted by THC administration to female but not male rats. In the prepulse inhibition test, MDMA-treated animals showed a decrease in prepulse inhibition at the most intense prepulse studied (80 dB), whereas in combination with THC it induced a similar decrease at 75 dB. THC decreased hippocampal Arc expression in both sexes, while in the frontal cortex this reduction was only evident in females. MDMA induced a reduction in ERK1/2 immunoreactivity in the frontal cortex of male but not female animals, and THC decreased prepro-orexin mRNA levels in the hypothalamus of males, although this effect was prevented when the animals also received MDMA. The results presented indicate that adolescent exposure to THC and/or MDMA induces long-term, sex-dependent psychophysiological alterations and they reveal functional interactions between the two drugs.     

2-Deoxy-D-glucose prevents and nicotinamide potentiates 3, 4-methylenedioxymethamphetamine-induced serotonin neurotoxicity

Neurotoxicity induced by different substituted amphetamines has been associated with the exhaustion of intracellular energy stores. Accordingly, we examined the influence of 2-deoxy-D-glucose (2-DG), a competitive inhibitor of glucose uptake and metabolism, and nicotinamide, an agent that improves energy metabolism, on 3, 4-methylenedioxymethamphetamine (MDMA)-induced 5-hydroxytryptamine (5-HT; serotonin) deficits. Administration of MDMA (15 mg/kg i.p.) produced a significant hyperthermia, whereas 2-DG caused a profound hypothermia that lasted throughout the experiment. When MDMA was given to 2-DG-treated rats, an immediate but transient hyperthermia occurred and was followed by a return to hypothermia. 2-DG had no effect on 5-HT concentrations in the frontal cortex, hippocampus, and striatum but prevented the neurotoxicity induced by MDMA. When rats were injected with 2-DG/MDMA and were warmed to prevent hypothermia, the protection afforded by 2-DG was abolished. Nicotinamide had no effect on body temperature of the rats, and the hyperthermia induced by the nicotinamide/MDMA treatment was similar to that of the saline/MDMA-treated rats. However, the long-term 5-HT deficits induced by MDMA were potentiated by nicotinamide in all the brain regions examined. Finally, no change on ATP concentrations in the frontal cortex, hippocampus, and striatum was observed up to 3 h after a single dose of MDMA. These results suggest that an altered energy metabolism is not the main cause of the neurotoxic effects induced by MDMA.     

Immunohistochemical localization of tryptophan hydroxylase and serotonin transporter in the carotid body of the rat

It has been proposed that serotonin (5-HT) facilitates the chemosensory activity of the carotid body (CB). In the present study, we investigated mRNA expression and immunohistochemical localization of the 5-HT synthetic enzyme isoforms, tryptophan hydroxylase 1 (TPH1) and TPH2, and the 5-HT plasma membrane transport protein, 5-HT transporter (SERT), in the CB of the rat. RT-PCR analysis detected the expression of mRNA for TPH1 and SERT in extracts of the CB. Using immunohistochemistry, 5-HT immunoreactivity was observed in a few glomus cells. TPH1 and SERT immunoreactivities were observed in almost all glomus cells. SERT immunoreactivity was seen on nerve fibers with TPH1 immunoreactivity. SERT immunoreactivity was also observed in varicose nerve fibers immunoreactive for dopamine beta-hydroxylase, but not in nerve fibers immunoreactive for vesicular acetylcholine transporters or nerve terminals immunoreactive for P2X₃ purinoreceptors. These results suggest that 5-HT is synthesized and released from glomus cells and sympathetic nerve fibers in the CB of the rat, and that the chemosensory activity of the CB is regulated by 5-HT from glomus cells and sympathetic nerve fibers.     

3,4-methylenedioxymethamphetamine ("Ecstasy") stimulates the expression of alpha1(I) procollagen mRNA in hepatic stellate cells.

3,4-Methylenedioxymethamphetamine, MDMA ("Ecstasy"), has been previously shown to produce cell necrosis and fibrosis in the liver. Our aim was to study the effect of MDMA on the type I collagen production by a cell line of hepatic stellate cells (HSC), the cell type mainly responsible for collagen synthesis in the liver. We demonstrated that MDMA increases alpha1(I) procollagen mRNA levels and that this increase correlates with glutathione depletion and enhanced hydrogen peroxide production by HSC. Pre-treatment with either glutathione monoethyl ester or deferoxamine prevents the MDMA-induced alpha1(I) procollagen mRNA expression, indicating oxidative stress to be a mediator of this effect. Lipid peroxidation was not detected in MDMA-treated cells and therefore does not seem to be involved in the pro-fibrogenic action of MDMA on HSC.     

In vivo analysis of serotonin clearance in rat hippocampus reveals that repeated administration of p-methoxyamphetamine (PMA), but not 3,4-methylenedioxymethamphetamine (MDMA), leads to long-lasting deficits in serotonin transporter function

p-Methoxyamphetamine (PMA) has been implicated in fatalities as a result of 'ecstasy' (MDMA) overdose worldwide. Like MDMA, acute effects are associated with marked changes in serotonergic neurotransmission, but the long-term effects of PMA are poorly understood. The aim of this study was to determine the effect of repeated PMA administration on in vitro measures of neurodegeneration: serotonin (5-HT) uptake, 5-HT transporter (SERT) density and 5-HT content in the hippocampus, and compare with effects on in vivo 5-HT clearance. Male rats received PMA, MDMA (4 or 15 mg/kg s.c., twice daily) or vehicle for 4 days and 2 weeks later indices of SERT function were measured. [(3)H]5-HT uptake into synaptosomes and [(3)H]cyanoimipramine binding to the SERT were significantly reduced by both PMA and MDMA treatments. 5-HT content was reduced in MDMA-, but not PMA-treatment. In contrast, clearance of locally applied 5-HT measured in vivo by chronoamperometry was only reduced in rats treated with 15 mg/kg PMA. The finding that 5-HT clearance in vivo was unaltered by MDMA treatment suggests that in vitro measures of 5-HT axonal degeneration do not necessarily predict potential compensatory mechanisms that maintain SERT function under basal conditions.     

Effects of microgravity and bone morphogenetic protein II on GFAP in rat brain

This studyevaluated effects of bone morphogenetic protein II (BMP) on glialfibrillary acidic protein (GFAP) in the brain of female Fischer 344 rats during 14 days of spaceflight. GFAP mRNA decreased invehicle-implanted rats flown on the space shuttle by 53 and 48% in thestratum moleculare and stratum lacunosum moleculare hippocampalsubregions, respectively. GFAP mRNA was not significantly affected byBMP implantation during spaceflight. Rats returning from spaceexhibited a 56% increase in serum corticosterone. BMP treatment didnot additively increase corticosterone elevations in microgravity butappeared to increase serum corticosterone and reduce GFAP mRNA in thestratum moleculare in control rats. These data suggest that exposure tomicrogravity reduces GFAP expression in hippocampal astrocytes.

     

Differences in the in vivo dynamics of neurotransmitter release and serotonin uptake after acute para-methoxyamphetamine and 3,4-methylenedioxymethamphetamine revealed by chronoamperometry

Illicit use of p-methoxyamphetamine (PMA) is rapidly increasing. However, little is known about the acute effects of PMA on neurotransmission in vivo. High-speed chronoamperometry was used to monitor neurotransmitter release and clearance in anesthetized rats after local application of PMA or 3,4-methylenedioxymethamphetamine (MDMA). In striatum, PMA caused less neurotransmitter release than MDMA. PMA-evoked release could be partially blocked by pre-treatment with a serotonin (5-HT) reuptake inhibitor, suggesting that evoked 5-HT release contributed to the electrochemical signal and was mediated by the 5-HT transporter (SERT). MDMA-evoked release was not blocked by a SERT inhibitor, suggesting that primarily DA was released. To study the effect of these amphetamines on clearance of 5-HT mediated specifically by the SERT, clearance of exogenously applied 5-HT was measured in the CA3 region of the hippocampus. In contrast to the striatum where 5-HT is cleared by both the SERT and the dopamine transporter (DAT), 5-HT is cleared primarily by the SERT in the CA3 region. This is also a region where neither PMA nor MDMA evoked release of neurotransmitter. The maximal inhibition of 5-HT clearance was greater after PMA than MDMA. These data demonstrate in vivo (1) brain region variability in the ability of PMA and MDMA to evoke release of neurotransmitter; (2) that clearance of 5-HT in the striatum is mediated by both the SERT and the DAT; (3) distinct differences in the amount and nature of neurotransmitter released in the striatum after local application of PMA and MDMA and (4) that PMA is a more efficacious inhibitor of 5-HT clearance in the hippocampus than MDMA. These fundamental differences may account for the more severe adverse reactions seen clinically after PMA, compared to MDMA.     

Castration enhances expression of glial fibrillary acidic protein and sulfated glycoprotein-2 in the intact and lesion-altered hippocampus of the adult male rat

This study concerns effects of the testes on two macromolecules in the rat hippocampus that were previously not known to be responsive to this endocrine axis. Castration for 3 weeks elevated the expression of glial fibrillary acidic protein (GFAP) and sulfated glycoprotein-2 (SGP-2) in male rat hippocampus, as shown by Northern blots and immunocytochemistry. SGP-2 mRNA was colocalized with GFAP, implying increased prevalence in astrocytes after castration. During hippocampal responses to deafferentation by entorhinal cortex lesions that damage the perforant path and induce synaptic reorganization, both mRNA and protein for SGP-2 and GFAP increase. Moreover, prior castration had an additive effect with entorhinal cortex lesions in the increase in GFAP and SGP-2 mRNA. These data suggest that testicular hormones regulate hippocampal astrocyte activity in intact adult rats as well as during synaptic reorganization in response to deafferenting lesions.