大鼠导水管周围灰质注射谷氨酸可Barrington使核神经 …

形态学研究已发现大鼠内侧视前区（ＭＰＯ）和导水管周围灰质（ＰＡＧ）发出大量轴突，投射至与排尿反射密切相关的Ｂａｒｒｉｎｇｔｏｎ核。本研究试图通过注射谷氨酸钠到ＭＰＯ或ＰＡＧ后，观察Ｂａｒｒｉｎｇｔｏｎ核内的Ｆｏｓ表达情况，来了解以上两通路的性质。将谷氨酸钠注射到ＭＰＯ后，只有少量Ｆｏｓ阳性神经元出现在Ｂａｒｒｉｎｇｔｏｎ核。而将谷氨酸钠注射到ＰＡＧ后，Ｂａｒｒｉｎｇｔｏｎ核内出现大量的Ｆｏｓ阳性神     

家兔脑桥被盖背外侧部向骶髓的直接投射

为研究家兔脑桥排尿反射通路的构成,本实验采用顺、逆行追踪技术结合免疫组化方法对家兔脑桥被盖背外侧部与骶髓的纤维联系进行了研究。将麦芽凝集素辣根过氧化物酶（ＷＧＡ－ＨＲＰ）或荧光素四甲基罗达明葡聚糖胺（ＴＭＲ）注射到骶髓后,在脑桥被盖背外侧部发现一团ＷＧＡ－ＨＲＰ或ＴＭＲ标记的神经元。为确定这些逆标细胞是否属于蓝斑核内的神经元,将ＴＭＲ注射例的脑桥切片用抗酪氨酸羟化酶（ＴＨ）抗体孵育并进行免疫荧光组化染色。结果显示,ＴＨ阳性细胞环绕于ＴＭＲ标记神经元周围,但未见ＴＭＲ／ＴＨ双标细胞。将ＷＧＡ－ＨＲＰ注射于脑桥被盖背外侧部后,在骶髓节段的骶髓副交感核、中间带灰质和后连合核等处发现有大量顺行标记的纤维和终末。结合在其他种属动物上的研究资料,推测位于家兔脑桥被盖背外侧部的这团神经元可能相当于在大鼠和猫相应部位发现的与脑桥排尿反射密切相关的Ｂａｒｒｉｎｇｔｏｎ核     

大鼠内侧视前区支配Barrington核内骶髓投射神经元的光,电镜研究

采用光镜及电镜双标记技术,对大鼠内侧视前区（ＭＰＯ）神经元发出的投射到脑桥Ｂａｒｉｎｇｔｏｎ核的轴突与其内投射到骶髓的神经元的胞体和树突之间的突触关系进行了探讨。将顺行追踪剂结合生物素的葡聚糖胺（ＢＤＡ）注射于ＭＰＯ用来标记它发出的轴突终末;将逆行追踪剂辣根过氧化物酶（ＨＲＰ）注射于脊髓腰骶段,以此标记Ｂａｒｉｎｇｔｏｎ核内投射至腰骶髓的神经元。光镜观察发现Ｂａｒｉｎｇｔｏｎ核内含有大量ＢＤＡ顺行标记的终末及ＨＲＰ逆行标记的树突和胞体,电镜观察确证了ＢＤＡ标记的轴突终末与ＨＲＰ标记的树突和胞体间存在直接的突触联系,且均为对称性突触。此结果提示ＭＰＯ可能通过这一直接的纤维联系调节排尿反射活动。     

胃肠道伤害性刺激引起大鼠孤束核与中脑导水管周围灰质神经 …

为研究中脑导水管周围灰质（ＰＡＧ）与孤束核（ＮＴＳ）内脏伤害性信息传递和调控之间的相互关系，采用免疫荧光组织化学方法结合荧光金（ＦＧ）逆行追踪技术，观察了大鼠ＮＴＳ和ＰＡＧ之间相互投射神经元在阳胃肠道伤害性刺激后的ＦＯＳ表达情况，给胃肠道以１％多聚甲醛的伤害性刺激后。ＦＯＳ阳性细胞主要出现中尾段ＮＴＳ的内侧亚核；在ＰＡＧ内，则主要出现于尾段ＰＡＧ的腹外侧区，将ＦＧ微量注射于ＰＡＧ后，再给予动物刺激     

MPTP处理的小鼠和6-OHDA损毁的大鼠帕金森病模型病理变化的比较

目的比较ＭＰＴＰ处理的小鼠与６－ＯＨＤＡ损毁大鼠ＰＤ模型的病理变化。方法应用免疫组化方法观察两种ＰＤ模型的中脑腹侧多巴胺能神经元,星形胶质细胞的变化。结果免疫组化方法结果表明：Ｃ５７ＢＬ小鼠在ＭＰＴＰ处理后,脑内酪氨酸羟化酶阳性神经元的数目从第４ｄ开始有所减少;黑质区域的ＧＦＡＰ免疫阳性星形胶质细胞数目从第１ｄ起即有增加。大鼠ＰＤ模型较早出现损毁侧ＴＨ免疫阳性神经元明显减少的现象,损毁２月后几乎完全消失;而在黑质区的ＧＦＡＰ免疫阳性星形胶质细胞数目增多现象出现较晚。结论两种动物模型从不同侧面反映了帕金森病的病理特征,６－ＯＨＤＡ损毁中脑ＤＡ能神经元制成的大鼠ＰＤ模型比ＭＰＴＰ处理的Ｃ５７ＢＬ小鼠ＰＤ模型更接近反映ＰＤ的病理变化。     

癫痫敏感大鼠脑内GFAP——免疫反应活性的变化

用红藻氨酸（ＫＡ）１０ｍｇ／ｋｇ（ｓ．ｃ）诱发大鼠出现癫病发作一个月后，经免疫细胞化学方法观察大鼠脑内神经胶质原纤维酸性蛋自（ＧＦＡＰ）－免疫反应产物的查化。发现海马的ＣＡ１，ＣＡ２，海马下脚和腹侧海马的海马门都位以及梨状皮层，内嗅皮层，隔区，杏仁核，伏隔核和尾核尾部的ＧＦＡＰ免疫染色阳性明显增强，这一现象可能与动物癫痫发作及发作后，癫痫敏感脑区的神经元损伤有关。     

急性脑梗死和Alzheimer病脑脊液高水平髓鞘素抗原B细胞免疫应答

目的确认急性脑梗死（ＡＣＩ）和Ａｌｚｈｅｉｍｅｒ病（ＡＤ）对髓鞘素碱性蛋白（ＭＢＰ）、髓鞘素结合糖蛋白（ＭＡＧ）和含脂质蛋白（ＰＬＰ）的Ｂ细胞免疫应答。方法采用酶联免疫斑点技术检测了ＡＣＩ、临床可能ＡＤ和其它神经疾病（ＯＮＤ）对照组患者外周血和脑脊液（ＣＳＦ）中ＭＢＰ、ＭＡＧ和ＰＬＰ抗体分泌细胞。结果ＡＣＩ、ＡＤ和ＯＮＤ患者外周血中均可检出ＩｇＧ、ＩｇＡ、ＩｇＭ三种表型ＭＢＰ、ＭＡＧ、ＰＬＰ抗体分泌细胞，无显著差异。但ＡＣＩ和ＡＤ患者ＣＳＦ中ＩｇＧ型ＭＢＰ、ＭＡＧ和ＰＬＰ抗体分泌细胞均呈显著性增高。结论ＡＣＩ急性脑缺血损伤和ＡＤ神经变性可能导致体内Ｂ细胞激活及ＣＮＳ内髓鞘素反应性Ｂ细胞免疫应答，其病理意义有待探讨。     

二次脑创伤后大鼠皮层脑血流及前列腺素变化及血红蛋白液的作用

目的：探讨二次脑创伤后大鼠皮层脑血流（ＣｏＣＢＦ）与前列腺素变化及双阿斯匹林联偶血红蛋白液（ＤＣＬＨｂ）的作用。方法：在一种新的大鼠加速性弥漫性脑损伤模型基础上，采用抽血及颈动脉结扎造成低血压及脑缺血、缺氧，观察大鼠ＣｏＣＢＦ与血栓素Ａ２（ＴＸＡ２）、前列环素（ＰＧＩ２）含量变化以及ＤＣＬＨｂ治疗作用。３２只ＳＤ大鼠随机分为假手术对照、单纯脑损伤、脑损伤并二次脑创伤及治疗四组。所有动物均气管内插管并实施同步生理监护。结果：伤后４小时，与假手术组对比，合并二次脑创伤组ＣｏＣＢＦ显著降低，ＴＸＡ２含量增高（Ｐ＜０．０５）；ＤＣＬＨｂ治疗组无ＣｏＣＢＦ降低，但ＴＸＡ２及ＰＧＩ２含量均有增高。结论：合并二次脑创伤组有ＣｏＣＢＦ降低及ＴＸＡ２含量增高，提示在其病理过程中存在脑血管痉挛及微血栓形成，导致脑缺血、缺氧。ＤＣＬＨｂ则可能通过增加ＰＧＩ２合成发挥脑保护作用。     

TGF—β高调在鼻腔给予AChR抑制EAMG中起重要作用

用放射标记的ｃＤＮＡ寡核苷酸探针，使用原位杂交技术检测表达子γ干扰素（ＩＦＮ－γ）白细胞介素４（ＩＬ－４）和转移生长因子β（ＴＧＦ－β）ｍＲＮＡ的单个核细胞（ＭＮＣ）。结果表明，实验性自身免疫性重症肌无力（ＥＡＭＧ）对照组大鼠Ｇｕｏ窝和腹股沟淋巴结（ＰＩＬＮ）的ＭＮＣ乙酰胆碱受体（ＡＣｈＲ）诱导的ＩＦＮ－γ，ＴＧＦ－βｍＲＮＡ表达细胞数明显增高，与给予ＰＢＳＣＦＡ注射组比较差异显著。鼻腔耐受组与Ｅ     

P物质对大鼠新鲜分离DRG神经元NMDA及GABA激活电流的调制作用

实验应用全细胞膜片钳技术在大鼠新鲜分离的背根神经节（ＤＲＧ）神经元胞体膜上观察到Ｐ物质（ＳＰ）对ＮＭＤＡ和ＧＡＢＡ激活电流有调制作用。单独给予ＳＰ（１０－８～１０－６ｍｏｌ／Ｌ）可在ＤＲＧ神经元记录到一幅值较小的，浓度依赖性的无明显去敏感之内向电流。预加ＳＰ３０ｓ后，其对ＮＭＤＡ和ＧＡＢＡ激活电流分别具有明显的增强和抑制作用，而且ＳＰ对ＮＭＤＡ和ＧＡＢＡ激活电流的增强和抑制作用也是剂量依赖性的。如ＳＰ浓度为１０－７ｍｏｌ／Ｌ时，可使ＮＭＤＡ激活电流较之对照增强４６．３±７．２％（ｘ±ｓ，ｎ＝８）；使ＧＡＢＡ激活电流比对照减小３８．９±７．８％（ｘ±ｓ，ｎ＝６）．ＳＰ的此种调制作用可以在同一ＤＲＧ神经元上观察到。     

Fos expression in rat pontine tegmental neurons following activation of the medial preoptic area

Fos immunohistochemistry was used to map the distribution of pontine neurons excited by activation of the medial preoptic area (MPO). Although we have previously shown that Barrington's nucleus receives a very dense focal input from the MPO, electrical stimulation of the preoptic area unexpectedly induced very little Fos expression in Barrington's neurons. These results suggest that the MPO→Barrington's projection utilizes a transmitter(s) that does not involve transduction of the Fos protein; alternatively, MPO afferents to Barrington's nucleus may be inhibitory in nature. As Barrington's nucleus plays a critical role in micturition, MPO projections to Barrington's nucleus may regulate voiding reflexes during sexual behavior. Interestingly, while the locus coeruleus (LC) proper receives only a sparse projection from the MPO, extensive Fos expression was present in LC. The finding of Fos immunoreactive LC neurons suggests that the excitatory influence of MPO may regulate LC neuronal activity and NE release during reproductive behaviors.     

大鼠Barrington核内脊髓投射神经元直接接受腰骶髓传入的电镜研究

将结合生物素的葡聚糖胺 (BDA)注射到大鼠腰骶髓后 ,在电镜下观察脑桥Barrington核内腰骶髓投射神经元与来自腰骶髓传入投射纤维间的突触联系。与先前的研究相一致 ,注射BDA到腰 6和骶 1节段后 ,光镜下可见Barrington核内出现大量顺行标记的神经末梢和一定数量的逆行标记细胞。电镜下发现标记的轴突末梢和标记的树突之间存在直接的突触连接。结果表明 ,Barrington核直接接受腰骶髓的传入投射 ,提示大鼠脑桥排尿反射的脊髓内上行投射通路中可能存在一条直接通路。     

GABAergic mechanism mediated via D receptors in the rat periaqueductal gray participates in the micturition reflex: an in vivo microdialysis study

The periaqueductal gray (PAG) is critically involved in the micturition reflex, but little is known about the neuronal mechanisms involved. The present study elucidated dynamic changes in dopamine (DA), glutamate and gamma-aminobutyric acid (GABA) in the rat PAG during the micturition reflex, with a focus on dopaminergic modulation using in vivo microdialysis combined with cystometrography. Extracellular levels of DA and glutamate increased, whereas levels of GABA decreased, in parallel with the micturition reflex. Application of a D(1) receptor antagonist into the PAG produced increases in maximal voiding pressure (MVP) and decreases in intercontraction interval (ICI), suggesting that the micturition reflex was facilitated by D(1) receptor blockade. The D(1) receptor antagonist prevented micturition-induced decreases in GABA efflux but had no effect on DA or glutamate. Neither a D(2) receptor antagonist nor a D(1)/D(2) receptor agonist affected these neurochemical and physiological parameters. Micturition-induced inhibition of GABA was not observed in 6-hydroxydopamine (6-OHDA)-lesioned rats, an animal model of Parkinson's disease. 6-OHDA-lesioned rats exhibited bladder hyperactivity evaluated by increases in MVP and decreases in ICI, mimicking facilitation of the micturition reflex induced by D(1) receptor blockade. These findings suggest that the micturition reflex is under tonic dopaminergic regulation through D(1) receptors, in which a GABAergic mechanism is involved. Bladder hyperactivity observed in 6-OHDA-lesioned rats may be caused by dysfunction of GABAergic regulation underlying the micturition reflex. The present findings contribute to our understanding not only of the neurophysiology of the micturition reflex but also of the pathophysiology of lower urinary tract dysfunction in patients with Parkinson's disease.     

Afferent projections to the pontine micturition center in the cat

The pontine micturition center (PMC) or Barrington's nucleus controls micturition by way of its descending projections to the sacral spinal cord. However, little is known about the afferents to the PMC that control its function and may be responsible for dysfunction in patients with urge-incontinence and overactive bladder. In five female cats, wheatgerm agglutinin-conjugated horseradish peroxidase (WGA-HRP) injections were made in the PMC and adjoining dorsolateral pontine tegmentum. Retrogradely labeled neurons were found in a large area, including the medullary and pontine medial and lateral tegmental field; dorsomedial, lateral, and ventrolateral periaqueductal gray matter (PAG); posterior hypothalamus; medial preoptic area (MPO); bed nucleus of the stria terminalis; central nucleus of the amygdala; and infralimbic, prelimbic, and insular cortices. To verify whether these areas indeed project specifically to the PMC or perhaps only to adjacent structures in the pontine tegmentum, in 67 cats (3)H-leucine or WGA-HRP injections were made in each of these regions. Five cell groups appeared to have direct connections to the PMC, the ventromedial pontomedullary tegmental field, the ventrolateral and dorsomedial PAG, the MPO, and the posterior hypothalamus. The possible functions of these projections are discussed. These results indicate that all other parts of the brain that influence micturition have no direct connection with the PMC.     

Central representation of bladder and colon revealed by dual transsynaptic tracing in the rat: substrates for pelvic visceral coordination

The neurocircuitry underlying regulation of bladder and distal colon function by Barrington's nucleus (the pontine micturition centre) was investigated in rats by identifying neurons which were transsynaptically labelled from these viscera, with pseudorabies virus (PRV) or genetically modified forms of PRV [PRV-beta-galactosidase (PRV-beta-Gal) and PRV-green fluorescent protein (PRV-GFP)]. PRV injection into the bladder or the colon of separate rats suggested an overlap in the distribution of bladder- and colon-related neurons in Barrington's nucleus, as well as a topographical arrangement whereby dorsal neurons were bladder-related and ventral neurons were colon-related. In rats injected with PRV-beta-Gal into one viscera and PRV-GFP into another, neurons in the major pelvic ganglion and lumbosacral spinal cord were primarily single-labelled at relatively early survival times. With longer survival times many double-labelled neurons (>70%) appeared in Barrington's nucleus, suggesting that individual Barrington's nucleus neurons are synaptically linked to preganglionic parasympathetic neurons which independently innervate the colon or the bladder. In addition to these dual-labelled neurons, Barrington's nucleus neurons which were single-labelled from either viscera were observed and these exhibited a viscerotopic organization consistent with the single-labelling studies. Together, these findings suggest the existence of three neuronal populations in Barrington's nucleus, one which is synaptically linked to both the bladder and the colon and the other two populations which are specifically linked to either viscera. These anatomical substrates may underlie the central coordination of bladder and colon function and play a role in disorders characterized by a coexistence of bladder and colonic symptoms.     

Fos expression induced by changes in arterial pressure is localized in distinct,longitudinally organized columns of neurons in the rat midbrain periaqueductal gray

The distribution of neurons expressing Fos within the periaqueductal gray (FAG) following pharmacologically induced high or low blood pressure was examined to determine (1) if PAG neurons are responsive to changes in arterial pressure (AP) and (2) the relationship of these cells to the functionally defined hypertensive and hypotensive columns in PAG. Changes in AP differentially induced robust Fos expression in neurons confined to discrete, longitudinally organized columns within PAG. Increased AP produced extensive Fos-like immunoreactivity within the lateral PAG, beginning at the level of the oculomotor nucleus. At the level of the dorsal raphe, Fos expression induced by increased AP shifted dorsally, into the dorsolateral division of PAG; this pattern of Fos labeling was maintained throughout the caudal one-third of PAG. Double-labeling for Fos and nicotinamide adenine dinucleotide phosphate diaphorase confirmed that Fos-positive cells induced by increased AP were located in the dorsolateral division of PAG at these caudal levels. Fos positive cells were codistributed, but not colocalized, with nicotinamide adenine dinucleotide phosphate diaphorase-positive cells. Decreased AP evoked a completely different pattern of Fos expression. Fos-positive cells were predominantly located within the ventrolateral PAG region, extending from the level of the trochlear nucleus through the level of the caudal dorsal raphe. Double-labeling studies for Fos and serotonin indicated that only 1–2 double-labeled cells per section were present. Saline infusion resulted in very few Foslike immunoreactive cells, indicating that volume receptor activation does not account for Fos expression in PAG evoked by changes in AP. These results indicate that (1) substantial numbers of PAG neurons are excited by pharmacologically induced changes in AP and (2) excitatory barosensitive PAG neurons are anatomically segregated based on their responsiveness to a specific directional change in AP. © 1995 Wiley-Liss, Inc.     

Nucleus paragigantocellularis afferents in male and female rats: organization, gonadal steroid receptor expression, and activation during sexual behavior

The supraspinal regulation of genital reflexes is poorly understood. The brainstem nucleus paragigantocellularis (nPGi) of rats is a well-established source of tonic inhibition of genital reflexes. However, the organization, gonadal steroid receptor expression, and activity of nPGi afferents during sex have not been fully characterized in male and female rats. To delineate the anatomical and physiological organization of nPGi afferents, the retrograde tracer Fluoro-Gold (FG) was injected into the nPGi of sexually experienced male and female rats. Animals engaged in sexual behavior 1 hour before sacrifice. Cells containing FG, estrogen receptor-alpha (ER(alpha)), androgen receptor (AR), and the immediate-early gene product Fos were identified immunocytochemically. Retrograde labeling from the nPGi was prominent in the bed nucleus of the stria terminalis, paraventricular nucleus (PVN), posterior hypothalamus, precommissural nucleus, deep mesencephalic nucleus, and periaqueductal gray (PAG) of both sexes. Sex differences were observed in the caudal medial preoptic area (MPO), with significantly more FG+ cells observed in males, and in the PAG and inferior colliculus, where significantly more FG+ cells were observed in females. The majority of regions that contained FG+ cells also contained ER(alpha) or AR, indicating sensitivity to gonadal steroids. The proportions of FG+ cells that co-localized with sex-induced Fos was high in the PVN of both sexes and high in the MPO of males but low in the PAG of both sexes despite the large number of PAG-nPGi output neurons and Fos+ cells in both sexes. The characterization of these afferents will lead to a further understanding of the neural regulation of genital reflexes.     

Nitric oxide synthase and glutamate receptor immunoreactivity in the rat spinal trigeminal neurons expressing Fos protein after formalin injection

Although recent studies implicated glutamate receptors and nitric oxide in nociception, much still needs to be known about their localisation in neurons involved in nociceptive transmission from the orofacial region. In this study, c-fos expression indicated by Fos immunohistochemistry in the caudal spinal trigeminal nucleus induced by subcutaneous injection of formalin into the lateral face of the rat was used as a marker for nociceptive neurons. The study sought to determine whether Fos-positive neurons express nitric oxide synthase, glutamate N-methyl-D-aspartate type receptor subunit 1, and glutamate alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid type receptor subunit 2/3; and whether they project to the thalamus. After formalin injection, many Fos-positive nuclei appeared in the superficial laminae of the ipsilateral trigeminal nucleus. Confocal laser scanning microscope revealed that almost all neurons with Fos immunofluorescent nuclei were colocalised with N-methyl-D-aspartate receptor 1, 94% with glutamate receptor 2/3 and 14% with nitric oxide synthase. Some of them were closely related to neurons labelled by nitric oxide synthase. Lastly, some of the Fos-positive neurons were labelled by tetramethylrhodamine-dextran injected into the trigeminothalamic tract or the thalamic region. The results suggested that activation of N-methyl-D-aspartate receptor 1 and glutamate receptor 2/3 upon glutamate release in response to noxious stimulation to the orofacial region might mediate c-fos expression in neurons involved in nociception. The expression of Fos in the neurons could also be mediated by nitric oxide produced from the same, as well as neighbouring neurons, when nociceptive stimulation persisted. Fos-positive neurons in the spinal trigeminal nucleus may project to the thalamus, relaying orofacial nociception to the higher sensory centre.     

The effect of air puff stress on c‐Fos expression in rat hypothalamus and brainstem: central circuitry mediating sympathoexcitation and baroreflex resetting

Psychological stress evokes increases in sympathetic activity and blood pressure, which are due at least in part to an upward resetting of the baroreceptor‐sympathetic reflex. In this study we determined whether sympathetic premotor neurons in the rostral ventrolateral medulla (RVLM), which have a critical role in the reflex control of sympathetic activity, are activated during air puff stress, a moderate psychological stressor. Secondly, we identified neurons that are activated by air puff stress and that also project to the nucleus tractus solitarius (NTS), a key site for modulation of the baroreceptor reflex. Air puff stress resulted in increased c‐Fos expression in several hypothalamic and brainstem nuclei, including the paraventricular nucleus (PVN), dorsomedial hypothalamus, perifornical area (PeF), periaqueductal gray (PAG), NTS and rostral ventromedial medulla, but not in the RVLM region that contains sympathetic premotor neurons. In contrast, neurons in this RVLM region, including catecholamine‐synthesizing neurons, did express c‐Fos following induced hypotension, which reflexly activates RVLM sympathetic premotor neurons. The highest proportion of NTS‐projecting neurons that were double‐labelled with c‐Fos after air puff stress was in the ventrolateral PAG (29.3 ± 5.5%), with smaller but still significant proportions of double‐labelled NTS‐projecting neurons in the PVN and PeF (6.5 ± 1.8 and 6.4 ± 1.7%, respectively). The results suggest that the increased sympathetic activity during psychological stress is not driven primarily by RVLM sympathetic premotor neurons, and that neurons in the PVN, PeF and ventrolateral PAG may contribute to the resetting of the baroreceptor‐sympathetic reflex that is associated with psychological stress.