酚妥拉明阻断去甲肾上腺素对大鼠束旁核痛反应神经元电活动的影响

目的：去甲肾上腺素及其α受体阻断剂酚妥拉明对大鼠束旁核痛反应神经元电活动的影响。方法：以串刺激右侧坐骨神经为伤害性刺激，用玻璃微电极细胞外记录大鼠束旁核痛反应神经元电活动。结果：脑室去甲肾上腺素抑制旁核束旁核痛兴奋神经元放电，促进痛抑制神经元放电，此作用可被酚妥拉明阻断。结论：酚妥拉明阻断去甲肾上腺素对大鼠束旁核痛反应神经元电活动的抑制作用，提示去甲肾上腺素的镇痛作用与α肾上腺素能受体关系密切。     

刺激猫红核对三叉神经脊束核尾侧亚核诱发放电的抑制作用及其途径

电刺激猫对侧或同侧红核对大多数三叉神经脊束核尾侧亚核神经元由刺激下齿槽神经引起的诱发放电有抑制作用,其中包括由伤害性刺激引起的诱发放电。向中缝大核内注射微量利多卡因后,红核的抑制时程明显缩短,甚至抑制作用完全消失。结果提示红核对三叉神经脊束核尾侧亚核的抑制作用主要是通过中缝大核实现的。     

电刺激尾核头部对丘脑后核痛相关神经元电活动的影响

在61只大鼠的丘脑后核(PO)记录到了516个神经元,其中44.19％是痛相关神经元。它们的痛反应能被吗排类物药所抑制。电刺激尾核头部对痛相关神经元主要产生抑制作用。本文就以上结果在痛觉生理和镇痛中的意义进行了讨论。     

脑室注射γ—氨基丁酸对大鼠尾核痛反应神经元放电的影响

本文在32只大鼠上,用玻璃微电极引导神经元放电,观察了脑室注射γ-氨基丁酸(GABA)后,尾核痛反应神经元电活动的规律和印防已毒素(picrotoxin,PIX)对GABA的阻断效应。研究所见:当脑内GABA含量增加时,尾核痛兴奋神经元(pain excitation neurons,PEN)电活动受到抑制,表现为痛诱发放电频率下降,潜伏期延长;痛抑制神经元(pain inhibition neurons,PIN)电活动加强,表现为抑制时程缩短,痛诱发放电频率增加。PIX可阻断这种效应。综上表明,GABA通过同时影响尾核PEN和PIN的电活动而产生镇痛效应。     

缰核神经元对伤害性刺激和压力感受性刺激的反应

作者曾证明缰核引起的痛觉改变和心血管活动密切相关。本实验向静脉内冲击式注射新福林（1～2mg／kg）引起动脉血压迅速短暂升高、以刺激压力感受器，用玻璃微电极观察和记录了缰核神经元放电对压力感受性刺激和伤害性刺激的反应。证明缰核一些神经元可接受压力感受性刺激和伤害性刺激，并且两者之间有密切联系。对伤害性刺激反应的单位，多对压力感受性刺激也有反应。即痛敏单位对压力感受性刺激主要呈兴奋反应（75％）,而抑制单位对其呈抑制反应（63％）。侧脑室注入吗啡后，缰核神经元对伤害性刺激的反应发生明显改变，同时对压力感受性刺激反应也改变。压力感受性兴奋单位或抑制单位对压力感受性刺激反应均增强，并伴有血压降低。提示吗啡加强缰核心血管反应神经元的活动与血压降低有关。说明缰核神经元可汇聚这两种不同性质刺激的传入信息，同时表明这种与痛和心血管反应有关神经元可能参与防御性心血管反应过程。     

刺激家兔面神经核腹内侧区对颏舌肌肌电活动的抑制效应

本研究在 2 6只氨基甲酸乙酯麻醉、断双侧迷走神经的健康成年家兔上观察了电、化学刺激面神经核腹内侧区 (vMNF)对颏舌肌肌电活动的影响。结果如下 :(1)长串电脉冲刺激vMNF导致颏舌肌肌电活动明显被抑制 ;(2 )在vMNF内微量注射谷氨酸钠 ,颏舌肌肌电活动出现明显的抑制效应 ;(3)单脉冲电刺激vMNF引起颏舌肌抑制反应的潜伏期为 (2 0 6± 0 4)ms。结果表明 :vMNF的兴奋能降低颏舌肌的肌电活动 ,从而提示其具有增强上呼吸道阻力的作用。     

刺激和损毁蓝斑核对网状巨细胞核神经元放电的影响

对水合氯醛浅麻醉的大鼠观察了电刺激或损毁蓝脏核(LC)对延髓网状巨细胞(NGC)神经元自发放电及伤害性反应的影响。结果如下:1)在143个NGC神经元中有63个伤害性神经元,12个会聚神经元,68个非伤害性神经元。在伤害性神经元中,伤害兴奋性的占2/3,伤害抑制性的占1/3。2)电刺激同侧及对侧LC可分别抑制64％及68％的伤害性神经元的伤害性反应,对大部分非伤害性神经元及会聚神经元无影响。3)损毁LC后,有45％(5/11个)伤害性神经元自发放电增加,67％(4/6个)伤害性神经元伤害性反应强度增加,且电刺激原LC位点的抑制作用减弱或消失。本工作说明,NGC伤害性神经元接受LC抑制性影响,对NGC及LC在抗伤害中的作用进行了讨论。     

胃电刺激对大鼠VMH胃扩张敏感神经元电活动及脑内催产素表达的影响

目的： 给予胃窦部以2组不同参数的电刺激，观察大鼠下丘脑腹内侧核（VMH）胃扩张（GD）敏感性神经元放电频率的变化及脑内有促进摄食作用的神经肽-催产素(OT) 表达的变化，为胃电刺激（GES）治疗肥胖的中枢作用机制及临床上治疗肥胖参数的选择提供理论依据。方法: ① 电生理实验：采用细胞外记录神经元单位放电方法，记录下丘脑腹内侧核神经元自发放电活动，根据神经元对胃扩张刺激反应的不同，分为胃扩张兴奋性神经元（GD-E）和胃扩张抑制性神经元（GD-I）， 并观察不同参数电刺激胃窦部，VMH内GD-E和GD-I放电频率的变化。②免疫组化实验：采用免疫荧光组织化学染色方法观察胃电刺激 2 h 对大鼠脑内OT阳性神经元表达的影响。结果: ① 电生理结果：GES1和GES2分别使60.4%和75.0%的GD敏感性神经元兴奋（P>0.05）。GES2和GES1分别可使GD-E神经元的放电频率平均增加343.59%±89.19%和97.44±33.67% (P<0.05)，GD-I神经元的放电频率平均增加366.30%±87.20%和112.00%±14.67% (P<0.05)。②免疫组化结果：GES1刺激胃窦部 2 h，室旁核（PVN）和视上核（SON）OT 免疫阳性神经元明显增加（P<0.05）。结论: GES可通过兴奋“饱中枢”-VMH内胃扩张敏感性神经元和增加脑内OT的表达来抑制摄食，且GES的作用效应与其强度有关。     

大鼠前连合核神经元对渗透压和血管紧张素Ⅱ刺激的神经性反应——脑片电生理研究

在大鼠下丘脑离体脑片上,用电生理细胞外记录法研究了前连合核神经元的放电频率及其波形。实验观察到的前连合核自发放电神经元有不规则或规则的连续性放电活动,少数神经元有短阵性放电或不放电。这些神经元中的绝大部分可因脑片浸浴液中给予血管紧张素Ⅱ而被兴奋(放电频率增加),约1/3—1/2神经元对高渗透压刺激呈抑制性反应(放电频率减少),也有少数神经元可因高渗透压刺激而兴奋或无反应。前连合核的这些电生理特性大致与视上核、室旁核相似,也有一些与视上核、室旁核不同之处。对记录后的脑片进行组织化学及免疫组织化学染色的结果表明,记录部位在前连合核内,该部位有许多催产素样免疫阳性社经元。上述研究结果提示:前连合核的大细胞神经分泌神经元在水平衡的调节中起重要作用。     

电刺激大鼠小脑顶核对下丘脑神经元放电活动的影响

目的:研究电刺激小脑顶核(fastigial nucleus,FN)及微电泳Glu(glutamic acid)、MK-801对大鼠下丘脑(hypothalamus,HT)神经元自发放电活动的影响,探讨电刺激FN治疗脑卒中大鼠的机制。方法:应用细胞外记录的方法,记录电刺激FN及微电泳药物对HT神经元放电的影响。结果:电刺激频率为20Hz(低频)时,50%的HT神经元的放电频率增高(P0.01),电刺激频率为100Hz(高频时),80%的HT神经元的放电频率增高(P0.01);Glu对HT有紧张性兴奋作用,其拮抗剂MK-801能够明显抑制Glu诱致的兴奋作用;70%HT神经元在微电泳MK-801的基础上进行100Hz电刺激FN时,高频刺激诱发的兴奋作用被明显削弱。结论:采用电刺激FN治疗脑卒中,其可能机制是通过Glu的兴奋作用来调节HT的异常活动。     

Fos expression in serotonergic neurons in the rat brainstem following noxious stimuli: an immunohistochemical double-labelling study

In order to detect whether there were different expression patterns of Fos protein induced by somatic or visceral noxious stimulation in the serotonergic neurons in the rat brainstem, an immunohistochemical double-labelling technique for serotonin (5-HT) and Fos was employed after subcutaneous or stomach injection of formalin. The two stimuli were matched in pilot experiments to produce maximum Fos expression. The expression of Fos protein in 5-HT-containing neurons (5-HT/Fos co-localized neurons) could be observed in the ventrolateral subdivision of the midbrain periaqueductal grey, interpeduncular nucleus, paramedian raphe nucleus, all of the brainstem raphe nuclei, the alpha part of the gigantocellular reticular nucleus and the lateral paragigantocellular reticular nucleus. The locations of the 5-HT/Fos co-localized neurons in the brainstem of animals subjected to somatic noxious stimulation were similar to those subjected to visceral noxious stimulation. However, the number and proportion of the 5-HT/Fos co-localized neurons in the median raphe nucleus and nucleus raphe obscurus of the rat subjected to visceral noxious stimulation were statistically greater than those in rats subjected to somatic noxious stimulation. These results suggest that serotonergic neurons in median raphe nucleus and nucleus raphe obscurus have a tendency to higher neuronal activity after visceral noxious stimulation.     

The Role of the Septal Nuclei in Controlling the Activity of Vagosensitive Neurons in the Solitary Tract Nucleus in Cats

Studies on cats anesthetized with a mixture of Nembutal and chloralose were performed to study the descending influences of single, paired, and frequent stimulation of the lateral septal nucleus (LSN) and bed nucleus of the stria terminalis (BNST) on the activity of viscerosensory neurons in the solitary tract nucleus, identified by stimulation of the cervical part of the vagus nerve. Of 70 units recorded in the solitary tract nucleus, 50 were identified as primary and secondary input vagus neurons. Single stimuli applied to the septal nuclei induced initial excitation in 30% (15 units) of vagus neurons. The latent period of these responses was 5-25 msec. Presentation of paired stimuli showed that loss of the ability to respond to the second stimulus occurred at interstimulus intervals of 10-200 and sometimes 300 msec. A total of 34% (17 units) of solitary tract nucleus neurons showed tonic changes in spontaneous activity in response to rhythmic stimulation. Increasing the stimulation frequency to 10-20 Hz led to very different changes in the spontaneous rhythm, i.e., wave-like changes (decreases and increases in frequency, secondary suppression) or complete inhibition, sometimes lasting up to 10 sec after stimulation ended. A small number of units (five) showed a blocking effect of septal discharges on the visceral afferent input in conditions of paired stimulation. These results lead to the conclusion that the LSN and BNST are involved in modulating the activity of bulbar viscerosensory neurons, though their influences are mediated mainly via oligo- and polysynaptic pathways via other limbic structures (hypothalamus, amygdala).     

胃肠道伤害性刺激诱导大鼠孤束核,视上核,室旁核内FOS蛋白的表达

用抗ＦＯＳ免疫组化技术，观察胃肠道伤害性刺激诱导大鼠孤束核、视上核、室旁核内ｃ－ｆｏｓ的表达，并结合抗ＴＨ免疫双重染色技术，探讨孤束核内儿茶酚胺能神经元与ＦＯＳ蛋白的关系，结果表明：ＦＯＳ阳性细胞主要分布于孤束核的连合亚核、内业核以及背侧周边区，说明孤束核是内脏伤害性信息初级传和冲动的直接反应区。在下丘脑内主要２于视上核和室旁核，提示视上核和室旁核在内脏伤害性刺激的传递中起中毒作用。在双标切片中，     

大鼠延髓至下丘脑室旁核的儿茶酚胺能投射神经元在胃伤害性刺激后的FOS表达

用ＨＲＰ注入下丘脑室旁核逆行追踪与抗Ｆｏｓ和抗酪氨酸羟化酶（ＴＨ）双重免疫细胞化学相结合的三重标记方法，对大鼠孤束核和延髓腹外侧区至下丘脑室旁核的儿茶酚胺能投射神经元对胃伤害性刺激后的ｃ－ｆｏｓ表达进行了观察，发现孤束核和延髓腹外侧区有７种不同的标记细胞：ＨＲＰ、Ｆｏｓ、ＴＨ单标细胞，Ｆｏｓ／ＨＲＰ、Ｆｏｓ／ＴＨ、ＨＲＰ／ＴＨ双标细胞，Ｆｏｓ／ＨＲＰ／ＴＨ三标细胞。上述７种标记细胞主要分布在延髓中、尾段孤束核的内侧亚核、连合亚核和延髓腹外侧区以及两者之间的网状结构。ＨＲＰ标记细胞以注射侧为主，对侧有少量分布。本文结果证明，大鼠孤束核和延髓腹外侧区至下丘脑室旁核投射的部分儿茶酚胺能神经元可能参与胃伤害性刺激的传导和调控。     

十二指肠NaCl刺激对大鼠孤束核c-fos表达的影响

目的：探讨生理状态下,大鼠十二指肠受到不同浓度氯化钠刺激后,孤束核（NTS）中神经元的活动性。方法：在大鼠十二指肠内恒流灌注0.86mol／L NaCl、0.15mol/L NaCl、去离子水以及10^-4mol／L 5-HT,然后对各处理组中不同的NTS部位进行c-fos免疫组化,并作定量分析。结果：0.86mol／L NaCl以及5-HT组可以引起NTS各平面c-fos阳性神经元数量的增加,而且明显高于0.15mol／L NaCl组、去离子水组以及假手术组。结论：在大鼠十二指肠给予0.86mol／L NaCl,可以经迷走神经通路上传到NTS,由NTS整合内脏信息上传至更高一级中枢;而给予0.15mol／L NaCl和去离子水,则不能激活NTS内的内脏感觉神经元。     

内脏伤害性刺激后大鼠臂旁核内Fos样神经元的亚核定位

目的观察内脏伤害性刺激后大鼠臂旁核内Fos阳性神经元的亚核分布。方法给予大鼠2%甲醛溶液灌胃后,用Fos蛋白免疫组织化学方法观察臂旁核内Fos阳性神经元在各亚核内的分布情况。结果Fos阳性神经元在臂旁核内的分布具有亚核特异性:外侧核外亚核、Kolliker-Fuse核和外侧核背亚核有大量分布;外侧核中央亚核有少量分布;其余各亚核偶见或未见分布。结论臂旁核的外侧核外亚核、Kolliker-Fuse核和外侧核背亚核在内脏伤害性刺激的传递过程中起中继作用。     

Reflection of the Spatial Characteristics of an Acoustic Signal in the Activity of Caudate Nucleus Neurons

Studies were performed on five dogs. Chronic experimental conditions were used to study the responses of individual neurons in the caudate nucleus to the spatial characteristics of an acoustic signal. The results showed that 92% of sound stimulus-responsive neurons in the head of the caudate nucleus in dogs generated asymmetrical responses to contra- and ipsilateral monaural stimulation, with contralateral stimulation being more effective. In 50% of caudate nucleus neurons, simultaneous stimulation of both sound inputs was more effective than contralateral stimulation. A total of 77% of sound-responsive caudate neurons demonstrated sensitivity to changes in the magnitude and sign of the interaural delay.     

Tetrodotoxin-Dependent Glycine Release in the Rat Nucleus Accumbens During Correction of Feeding Behavior

Studies on male Sprague-Dawley rats using vital intracerebral microdialysis and high-performance liquid chromatography addressed changes in glycine levels in the intercellular space of the nucleus accumbens during forced correction of feeding behavior. The results showed that presentation to food-consuming rats of a tone previously combined with pain stimulation induced increases in extracellular glycine levels in the nucleus accumbens, which was completely prevented by administration of the sodium channel blocker tetrodotoxin (1 µm) into this structure. Isolated presentation of the tone previously combined with pain stimulation and combined presentation of food and a tone not associated with pain stimulation were not accompanied by glycine release. These data provide evidence for the involvement of glycine mechanisms of the nucleus accumbens in processes associated with forced correction of feeding behavior.__________Translated from Rossiiskii Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 90, No. 7, pp. 833–839, July, 2004.     

催产素对大鼠尾核痛反应神经元放电的影响

实验用Ｗｉｓｔｅｒ大鼠４８只，在尿酯（１．０ｇ／ｋｇ）麻醉下行常规手术，人工呼吸条件下进行实验。用玻璃微电极引导尾核中痛反应神经元（ＰＥＮ、ＰＩＮ）的放电，研究外源、内源催产素（ＯＴ）对其放电的影响。结果：１．尾核内微量注射ＯＴ（０．００５Ｕ／２μ可明显抑制ＰＥＮ放电频率，延长放电潜伏期．可缩短ＰＩＮ放电抑制时时程、增加放电频率。以上放电变化高峰出现在注药后６ｍｉｎ，注药后１５ｍｉｎ恢复，２．电刺