高频电刺激大鼠丘脑底核抑制背侧中缝核5-羟色胺表达

本研究探讨高频电刺激丘脑底核对大鼠背侧中缝核5-羟色胺(5-HT)表达的影响。实验动物分两组,刺激组给予高频电流(130Hz,100μA,60μs)刺激大鼠右侧丘脑底核,对照组大鼠右侧丘脑底核植入电极,但无电流输出。刺激结束后,用免疫组织化学方法染色背侧中缝核5-HT能神经元,检测背侧中缝核5-HT能神经元的数量和平均灰度值。结果显示电刺激组背侧中缝核5-HT阳性神经元数目与对照组比明显减少(t(13)=3.786,P=0.002),并且神经递质5-HT表达量减少,平均灰度值显著增高(t(13)=7.917,P<0.001)。本实验结果表明高频电刺激丘脑底核对背侧中缝核5-HT能神经元有抑制作用,在应用高频电刺激丘脑底核治疗Parkison病运动障碍时出现的情绪障碍可能与其有关。     

人胎盘蜕膜细胞5-羟色胺及其受体的免疫组织化学及原位杂交研究

目的　观察 5 -羟色胺 (5 - HT)及其受体在人胎盘的定位及其含量的周龄变化。　方法　采用免疫组织化学、原位杂交及图像分析技术。　结果　人胎盘蜕膜细胞呈 5 - HT及其受体免疫反应性 ,两种阳性反应物质均分布于胞质 ,胞核为阴性。蜕膜细胞同样含有 5 - HT1 A受体 m RNA杂交信号。蜕膜细胞 5 - HT及其受体免疫反应产物的相对含量随妊娠周龄的增加而增加。　结论　人胎盘蜕膜细胞既能产生 5 - HT,又能表达 5 - HT受体。说明 5 -HT对蜕膜细胞可能具有自调节作用。     

大鼠海马内5-羟色胺及其受体5-HT2A的表达

目的:观察5-羟色胺(5-HT)纤维和5-HT2A受体在大鼠海马CA1、CA2和CA3三个区域的分布特点.方法:用5-HT递质和5-HT2A受体特异性抗体的免疫组织化学显色以及图像处理与分析.结果:在海马内,抗5-HT2A受体的免疫反应阳性产物主要位于锥体细胞的细胞膜和树突,树突染色较深;5-HT2A受体的阳性胞体在C...     

几种神经递质对大鼠丘脑底核神经元自发放电活动的影响

采用微电泳法观察了谷氨酸（Glu）、乙酰胆碱（Ach）、多巴胺（DA）和γ－氨基丁酸（GABA）等药物对大鼠STN神经元自发放电活动的影响。结果表明：Ach、Glu和DA分别使67．05％（59／88），92．94％（79／85），90．02％（80．06）神经元自发放电频率加快，它们的作用依赖于电流强度。GABA抑制所有神经元的自发放电活动，其作用也依赖于电流强度。在微电泳Ach或Glu过程中，给予GABA可拮抗其兴奋作用。双钴碱（Bic）可使78．79％）（52／66）的神经元自发放电频率加快，阿托品（ATR）可使60％（15／25）神经元自发放电减少，给药前后放电频率差异显著（P＜0．05）。而MK－801对STN自发放电影响较小，但能拮抗Glu的兴奋作用。结果表明：GABA、Ach、Glu和DA等递质活动在同一STN神经元有重要会聚作用，GABA和Ach分别对STN神经元有紧张性抑制性及兴奋作用。     

大鼠胃肠道5-羟色胺免疫活性内分泌细胞的分布及形态学观察

本文用肠卷石蜡切片的免疫组织化学反应(硫酸镍铵加强的PAP法)对5只大鼠胃肠道的5-羟色胺(5-HT)免疫活性内分泌细胞的分布及形态进行了研究。结果表明,大鼠胃肠道5-HT免疫活性内分泌细胞在胃幽门部、十二指肠和结肠的密度最高,在空肠、回肠、盲肠和直肠密度中等,在胃体部密度最低。5-HT免疫活性内分泌细胞的形状多样。有的细胞有几个突起穿行于其它上皮细胞之间;有的细胞的基底部有突起,突起的末端含有5-HT阳性物质;有时还见突起穿过基膜进入固有层内。多数细胞的5-HT阳性物质释放到腺腔面和肠腔面,说明EC细胞有内、外两种分泌方式释放5-HT。     

大鼠神经系统内5-羟色胺_(1A)受体亚型的定位分布(英文)

应用免疫组织化学技术观察了大鼠神经系统内 5 -羟色胺 1A受体亚型 ( 5 -HT1 AR)免疫阳性结构的分布。结果显示 :5 -HT1 AR免疫阳性结构主要分布于梨状皮质、隔核、丘脑腹后核、丘脑网状核、杏仁基外侧核、Purkinje细胞层、红核、面神经核、斜方体核等 ;在海马、额叶皮质、丘脑背内侧核、脚间核、三叉神经中脑核、中缝背核、三叉神经脊束核、脊髓背角浅层、背根神经节和三叉神经等结构内有中等强度的分布 ;在嗅球、尾壳核、苍白球、斜角带核、终纹床核、缰核、黑质、上橄榄等部位有弱的分布。本文的结果提示 5 -HT1 AR阳性结构广泛地分布在大鼠神经系统 ,它们可能介导 5 -HT在神经系统中的多种生理功能     

5-羟色胺3A受体在成年小鼠海马中间神经元中的分布

目的:利用成年5-HT3AR-BACEGFP转基因小鼠,研究5-羟色胺3A受体(5-HT3AR)在海马中间神经元中的分布情况。方法:成年5-HT3AR-BACEGFP转基因小鼠经心脏灌注固定后,利用免疫荧光双标记方法,并结合激光共焦显微镜扫描技术,观察5-HT3AR在成年5-HT3AR-BACEGFP转基因小鼠海马中不同中间神经元内的表达和分布情况。结果:5-HT3AR在成年小鼠整个海马中都有分布,且主要在CA1区、CA2/CA3区和齿状回有大量5-HT3AR免疫阳性细胞;激光共聚焦显微镜下观察到5-HT3AR阳性产物在细胞核、细胞浆和树突上均有表达;免疫荧光双标实验结果表明5-HT3AR阳性产物在CB(calbindin),CR(calretinin),Reelin,Som(somatostatin),NPY(neuropeptide Y)和VIP(vasoactive intestinal peptide)免疫阳性神经元中表达,但在PV(parvalbumin)免疫阳性神经元中不表达。定量结果显示:几乎所有的VIP阳性神经元均表达5-HT3AR阳性,约3/4的CR阳性神经元表达5-HT3AR,约1/2的CB、Reelin、NPY和Som阳性神经元表达5-HT3AR阳性;约1/4的5-HT3AR阳性神经元中表达Reelin,1/5的表达Som,5-HT3AR/CB和5-HT3AR/CR双标神经元各占5-HT3AR阳性神经元的1/10左右。结论:5-HT3AR-BACEGFP转基因小鼠能够作为研究海马中5-HT3AR功能及其在中间神经元中的作用机制研究的工具鼠。     

大鼠三叉神经节神经元5-羟色胺激活电流及其特征

采用全细胞膜片钳技术观察大鼠三叉神经节神经元5-羟色胺激活电流(I5-HT)及其特征。在大多数受检细胞(64／87,73.6％)特别是中、小型细胞,外加5-HT可引起一快去敏感的内向电流,此内向电流可被5-HT3受体特异性激动剂2-甲基-5-羟色胺所模拟,被5-HT3受体拮抗剂ICS 250-930可逆性阻断。I5-HT浓度-反应曲线的阈浓度为3×10-7mol／L,饱和浓度约为3×10-3mol／L,EC50为21.4+2.2μmol／L,Hill系数为0.96。I5-HT的翻转电位在-2.5 mV左右。胞内透析GDP-β-S证明I5-HT不依赖于G蛋白而存在。本研究结果为了解5-HT3受体介导电流及其特征提供了有关的资料。     

5-羟色胺增强甘氨酸激活的大鼠脊髓背角浅层神经元的全细胞电流

应用制霉菌素穿孔膜片钳全细胞记录技术研究了5－HT对急性分离的大鼠脊髓背角浅层（Ⅰ、Ⅱ层）神经元甘氨酸激活的全细胞电流的调控作用。实验结果表明：（1）在脊髓背角浅层神经元，甘氨酸作用于士的宁敏感型的甘氨酸受体，在钳制电位为-40mV时，可引起内向电流（IGly）；（2）5－HT呈浓度依赖性的增强Gly反应；（3）5－HT的增强作用既不改变IGly的平衡电位，也不影响Gly与受体的亲和力；（4）5－HT2受体激动剂α-甲基-5－HT能模拟5－HT的增强效应；而5－HT2受体的拮抗剂ketanserine可阻断5－HT对IGly的增强作用；（5）蛋白激酶C（PKC）的抑制剂chelerythrine可抑制5－HT对IGly的增强作用。本研究的结果说明：5－HT可呈浓度依赖性地增强大鼠脊髓背角浅层神经元的IGly，5－HT经5－HT2受体介导其对IGly的调控，脊髓背角浅层神经元内经PKC的信号转导途径在5－HT对IGly的增强效应中起重要的作用。本研究的结果提示5－HT和Gly的相互作用在脊髓水平的伤害性信息传递和调控过程中可能具有重要的意义。     

增强5-羟色胺能神经元活动对激光穴位刺激镇痛作用的影响

本实验采用5-HT的前体物质L-色氨酸或提高脑内5-HT含量的胰岛索对家兔或绵羊进行静脉注射,然后用CO_2激光或He-Ne激光刺激动物腰荐十字部“百会”穴,应用钾离子透入法测取痛阈,观察它们对激光穴位刺激镇痛作用的影响。结果表明,L-色氨酸和胰岛素均能显著提高家兔或绵羊激光穴位刺激镇痛效果,提示5-羟色胺能神经元及其介质5-HT也参与激光穴位刺激镇痛。     

5-HT inhibits synaptic transmission in rat subthalamic nucleus neurons in vitro

The subthalamic nucleus (STN) plays a pivotal role in normal and abnormal motor function. We used patch pipettes to study effects of 5-HT on synaptic currents evoked in STN neurons by focal electrical stimulation of rat brain slices. 5-HT (10 microM) reduced glutamate-mediated excitatory postsynaptic currents (EPSCs) by 35+/-4%. However, a much higher concentration of 5-HT (100 microM) was required to inhibit GABA-mediated inhibitory postsynaptic currents (IPSCs) to a comparable extent. Concentration-response curves showed that the 5-HT inhibitory concentration 50% (IC50) for inhibition of IPSCs (20.2 microM) was more than fivefold greater than the IC50 for inhibition of EPSCs (3.4 microM). The 5-HT-induced reductions in EPSCs and IPSCs were accompanied by increases in paired-pulse ratios, indicating that 5-HT acts presynaptically to inhibit synaptic transmission. The 5-HT1B receptor antagonist NAS-181 significantly antagonized 5-HT-induced inhibitions of EPSCs and IPSCs. These studies show that 5-HT inhibits synaptic transmission in the STN by activating presynaptic 5-HT1B receptors.     

Neuronal responses to 5-hydroxytryptamine in the red nucleus of rats

The effects of microiontophoretic 5-hydroxytryptamine (5-HT) on the firing rate of red nucleus (RN) neurons were studied in urethane-anesthetized rats. The background discharge rate of almost all the neurons tested (97%) was modified by 5-HT, and generally increased (89%). Responses were dose dependent. Twenty-three percent of the excitatory responses were preceded by a short inhibitory phase. No significant difference in the effect of 5-HT was found between those RN neurons that project to the spinal cord and those that do not. The excitatory responses to 5-HT were blocked or greatly reduced by the 5-HT antagonists methysergide and ketanserin, and were even reversed in some cases. The 5-HT₂/5-HT_1A antagonist spiperone, in small doses, also blocked the transient inhibitory phases in addition to the excitatory effects. In RN neurons exhibiting a short-lasting inhibition in the response to 5-HT, the 5-HT_1A agonist 8-hydroxy-2(di-n-propyl-amino)tetralin (8-OH-DPAT) induced inhibitory effects. These results support the hypothesis that 5-HT exerts control throughout the RN, mostly by acting on 5-HT₂ receptors. Furthermore, an influence of this amine on the electrical activity of small groups of RN neurons by 5-HT_1A receptors, and eventually by different mechanisms, appears probable. The functional significance of serotoninergic control of RN neuronal activity is discussed.     

5-HT excites globus pallidus neurons by multiple receptor mechanisms

Anatomical and neurochemical studies indicated that the globus pallidus receives serotonergic innervation from raphe nuclei but the membrane effects of 5-HT on globus pallidus neurons are not entirely clear. We address this question by applying whole-cell patch-clamp recordings on globus pallidus neurons in immature rat brain slices. Under current-clamp recording, 5-HT depolarized globus pallidus neurons and increased their firing rate, an action blocked by both 5-HT(4) and 5-HT(7) receptor antagonists and attributable to an increase in cation conductance(s). Further experiments indicated that 5-HT enhanced the hyperpolarization-activated inward conductance which is blocked by 5-HT(7) receptor antagonist. To determine if 5-HT exerts any presynaptic effects on GABAergic and glutamatergic inputs, the actions of 5-HT on synaptic currents were studied. At 10 microM, 5-HT increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) but had no effect on both the frequency and amplitude of miniature inhibitory postsynaptic currents (mIPSCs). However, 5-HT at a higher concentration (50 microM) decreased the frequency but not the amplitude of the mIPSCs, indicating an inhibition of GABA release from the presynaptic terminals. This effect was sensitive to 5-HT(1B) receptor antagonist. In addition to the presynaptic effects on GABAergic neurotransmission, 5-HT at 50 microM had no consistent effects on glutamatergic neurotransmission, significantly increased the frequency of miniature excitatory postsynaptic currents (mEPSCs) in 4 of 11 neurons and decreased the frequency of mEPSCs in 3 of 11 neurons. In conclusion, we found that 5-HT could modulate the excitability of globus pallidus neurons by both pre- and post-synaptic mechanisms. In view of the extensive innervation by globus pallidus neurons on other basal ganglia nuclei, this action of 5-HT originated from the raphe may have a profound effect on the operation of the entire basal ganglia network.     

Biphasic modulation of spontaneous activities of entopeduncular neurons by systemic application of apomorphine in anesthetized cats

The responses of entopeduncular neurons to apomorphine were investigated with extracellular recording methods in anesthetized cats. Apomorphine was applied intravenously in increasing doses, which cumulatively doubled with each addition (5-640 micrograms/kg). The spontaneous firing rates of entopeduncular neurons, which were inhibited by electrical stimulation of the caudate nucleus, increased when lower doses of apomorphine (5-20 micrograms/kg) were applied. However, higher doses (40-640 micrograms/kg) produced a dose-dependent decrease in the firing rate. The results suggest that there are direct and indirect effects of systemically administered apomorphine on entopeduncular neurons which may contribute to biphasic responses in the spontaneous discharge rate.     

PTSD样行为异常大鼠中缝背核5-HT1A受体的改变

目的观察创伤后应激障碍(PTSD)样行为异常大鼠中缝背核(DRN)神经元5-HT1A受体表达变化,为探讨PTSD的发病机制提供资料。方法成年健康雄性Wistar大鼠60只,随机分为连续单一刺激(SPS)模型1d、4d、7d组及正常对照组,采用免疫组化、Western blot方法检测PTSD样行为异常大鼠中缝背核神经元5-HT1A受体表达变化。结果 SPS刺激后1d大鼠中缝背核神经元5-HT1A受体表达水平开始逐渐升高,第4天高于第1天,第7天高于第4天。结论 PTSD样大鼠中缝背核神经元5-HT1A受体呈规律性过表达。     

Effect of stimulation of subthalamic nucleus on grooming movements and their rhythmicity in pups and mature rats

The effect of rhythmic stimulation of subthalamic nucleus on grooming movements and their rhythmicity was studied on mature rats and on 13- and 14-day rat pups. Unilateral monopolar stimulation of subthalamic nucleus was performed on unrestrained animals via implanted electrodes. This stimulation activated virtually all grooming movements (scratching, hair-plucking, licking, and body-shaking); the effect was most pronounced in pups. Acceleration of the rhythm of grooming movements was observed only in rat pups for hair-plucking and scratching on the contralateral side relatively to the stimulated nucleus. In mature rats stimulation of the subthalamic nucleus prolonged grooming movements in most cases, but did not increase their number and rhythm. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 138, No. 9, pp. 244–246, September, 2004     

Effect of stimulation of subthalamic nucleus on grooming movements and their rhythmicity in pups and mature rats

The effect of rhythmic stimulation of subthalamic nucleus on grooming movements and their rhythmicity was studied on mature rats and on 13- and 14-day rat pups. Unilateral monopolar stimulation of subthalamic nucleus was performed on unrestrained animals via implanted electrodes. This stimulation activated virtually all grooming movements (scratching, hair-plucking, licking, and body-shaking); the effect was most pronounced in pups. Acceleration of the rhythm of grooming movements was observed only in rat pups for hair-plucking and scratching on the contralateral side relatively to the stimulated nucleus. In mature rats stimulation of the subthalamic nucleus prolonged grooming movements in most cases, but did not increase their number and rhythm.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 9, pp. 244–246, September, 2004     

Type I 5-HT receptors in rats with amnesia

Institute of Physiology, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR, V. A. Matyukhin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 7, pp. 51–52, July, 1989.     

The adrenaline microinjection into the median raphe nucleus induced hypophagic effect in rats submitted to food restriction regimen

The effect of the equimolar doses (6, 20 and 60 nmol) of either adrenaline (AD) or noradrenaline (NA) microinjected into the median raphe nucleus (MR) on feeding behavior of food-restricted rats (15 g/day/rat) was investigated. The data indicated that 20 nmol AD microinjection, but not NA, into the MR decreased the animal food intake. This hypophagic effect induced by AD may be ascribed to a feeding bout conclusion (satiation process) and not to any changes in non-ingestive behaviors induced by drug microinjection. Since equimolar doses of NA failed to change the animal feeding behavior, it is possible to say that AD-induced hypophagia may be due to either changes in tonic stimulatory control exerted by endogenous noradrenaline on MR or to AD-β₂ receptor activation in the MR. We claim that such activation may be much more importantly exerted by adrenaline-containing afferents to MR neurons involved with ingestive behavior than by noradrenergic inputs.