兔脑内Orexin B免疫阳性神经元的分布定位

采用免疫组织化学方法研究了10只青紫蓝兔脑内Orexin B免疫阳性神经元的分布定位。结果显示,Orexin B免疫阳性神经元分布于下丘脑的室旁核、背内侧核、穹隆周核、外侧区和后区以及底丘脑的未定带。以下丘脑背内侧核、穹隆周核和外侧区的阳性神经元数量较多,下丘脑室旁核、后区和未定带较少。表明了兔脑内Orexin B免疫阳性神经元的分布与Orexin A免疫阳性神经元的分布存在一些差异,提示两种Orexin的产生部位和生理功能可能也存在差异。     

大鼠下丘脑内一氧化氮合酶阳性神经元的分布

用ＮＡＤＰＨ－ｄ组织化学方法观察了大白鼠下丘脑内一氧化氮合酶（ＮＤＳ）阳性神经元的分布及形态特征。结果显示：在视上核、室旁核的大细胞部、环状核、穹窿周核、下丘脑外侧区、下丘脑腹内侧核、下丘脑背内侧核、乳头体区大部分核团均可见一氧化氮合酶阳性神经元聚集成团。在视前内侧区、视前外侧区、下丘脑前区、下丘脑背侧区、下丘脑后区、室周核、室旁核小细胞部及穹窿内可见散在的一氧化氮合酶阳性神经元。室周核内可见呈阳性反应的接触脑脊液神经元的胞体及突起。一氧化氮合酶阳性神经元大多可见突起,有的突起上可见１～２级分支,并可见膨体。下丘脑大部分区域内可见阳性神经纤维。弓状核内可见许多弧形纤维连于第三脑室室管膜和正中隆起。     

大鼠下丘脑视前区神经元内雌激素受体α的表达--免疫组织化学研究

了解雌激素受体α(estrogen receptor alpha, ERα)在大鼠脑的分布及大鼠下丘脑视前区雌激素受体样阳性神经元的生后发育规律.用免疫组织化学反应方法结合图像分析仪检测雌性大鼠下丘脑视前区雌激素受体样阳性神经元的数量和灰度值.ERα分布于Calleja岛、梨形核、外侧隔核、基底前脑胆碱能神经元各群、终纹床核、下丘脑内侧视前区、室周核、腹内侧核、弓状核和结节乳头核、再连合和前内侧丘脑核、杏仁核复合体、梨形皮质和穹窿下器官.相比之下,皮质和海马内仅见几个分散的 ERα样阳性神经元.而纹状体内未见ERα样阳性神经元.ERα免疫反应产物主要位于细胞核内,蓝黑色.在成年雌性大鼠下丘脑内侧视前区(medial preoptic area, MPA)神经元的胞浆和突起内可见较弱的ERα免疫反应产物.在MPA内,生后1天可见ERα表达,随着大鼠的生后发育,成年时达到高峰.与成年大鼠比较,老年雌性大鼠雌激素受体样阳性神经元数量减少10.05%,P＞0.05,差异无显著性;平均灰度减少41.57%,P＜0.05,差异有显著性.老年雌性大鼠下丘脑MPA内ERα表达下调,可能与卵巢功能减退而导致情感、记忆变化有关.     

nov基因的表达与脑的种系发育分化平行相关

用地高辛标记的cRNA探针原位杂交组织化学方法研究了鲢、鸡、牛、犬和猫脑肾母细胞瘤过度表达是基因阳性神经元的比较发育。结果显示,低等脊椎动物鲢脑仅有少量nov mRNA阳性神经元,分布于延髓的迷走神经背核、三叉神经背核、丘脑前核、丘脑后核、下丘脑背侧核、下丘脑外侧核。鸡脑阳性神经元除广泛分布于脑干外,小脑、丘脑的多数核闭、下丘脑的背侧核、腹侧核和后核以及大脑纹状体等多数脑区也有一定分布。哺乳动物牛、犬和猛脑中nov mRNA阳性神经元广泛分布,在脑干、小脑、间脑和大脑都检测到强烈阳性信号。以上结果表明,在众低等脊椎动物到高等脊椎动物的进化过程中nov基因的表达也从低级中枢向高级中枢扩展,提示该基因的表达与脑的种系发育、脑功能的分化平行相关。     

侧脑室注射肾上腺髓质素增加大鼠心血管相关核团中c-fos的表达并激活脑内一氧化氮神经元

本研究利用Fos蛋白和一氧化氮合酶(nNOS)双重免疫组化方法,观察侧腑脑室注射肾上腺髓质素(adrenomedullin,ADM)对大鼠心血管相关核中c-fos表达及一氧化氮神经元的影响,以探讨ADM在中枢的作用部位并研究其在中枢的作用是否有NO神经元参与。侧脑室注射ADM(1nmol／kg,3nmol／kg)诱发脑干的孤束核、最后区、蓝斑核、臂旁核和外侧巨细胞旁核,下丘脑的室旁核、视上核才腹内侧核以及前脑的中央杏仁核和外侧缰核等多个部位的心血管中枢出现大量Fos样免疫反应神经元。侧脑室注射ADM(3nmol／kg),引起脑干的孤束核、外侧巨细胞旁核,下丘脑的室旁核、视上核内的Fos-nNOS双标神经元增加;ADM(1nmol／kg)亦可引起室旁核、视上核内的Fos-nNOS双标神经元增加,而对孤束核、外侧巨细胞旁核内的Fos-nNOS双标神经元无影响。降钙素基因相关肽(calcitonin gene—related peptide,CGRP)受体拈抗剂CGRP8-37(30nmol／kg)可明显减弱此效应。以上结果表明,ADM可兴奋脑内多个心血管相关核闭的神经元并激活室旁核、视上核、孤束核及外侧巨细胞核内一氧化氮神经元,此效应可能部分山CGRP受体介导。     

树脑β－内啡肽能神经元胞体和纤维分布的研究

本文用免疫组织化学方法和免疫电镜方法对１４只树脑β－内啡肽能神经元胞体和纤维的分布及其在细胞器的定位进行了研究。结果表明，本文首次报道在Ｂｒｏｃａ斜角带观察到β－内啡肽免疫反应阳性神经元胞体，电镜观察到β－内啡肽免疫反应物质定位于大颗粒囊泡内的小颗粒上和粗面内质网上。下丘脑弓状核及其附近区域观察到β－内啡肽免疫反应阳性神经元胞体。在室周区、室旁核、第３脑室室管膜下层及室管膜上皮细胞间、内侧基底下丘脑及其外侧区、正中隆起内带和外带部可见到β－内啡肽免疫反应阳性纤维和串珠状的膨体。对β－内啡肽的释放途径及其调节因素作了探讨。     

腹腔内注射LPS和SEB诱发Ⅰ型IL-1受体在大鼠下丘脑室旁核和视上核的表达增强

目的　为揭示脑内参与神经免疫调节过程的部位和核团。方法　大鼠腹腔内给予细菌内毒素脂多糖 (LPS)或葡萄球菌肠毒素B (SEB) ,用免疫组织化学方法观察了Ⅰ型IL 1受体在脑内表达的变化。结果　Ⅰ型IL 1受体在正常成年大鼠脑内有广泛的表达 ,隔区、视前内侧区、新皮质、海马、下丘脑室旁核、视上核、下丘脑腹内侧核、弓状核和正中隆起等部位有较多Ⅰ型IL 1受体阳性细胞。与生理盐水对照组和非免疫应激对照组 (强迫游泳 )比较 ,LPS或SEB腹腔注射后大鼠下丘脑室旁核和视上核中表达Ⅰ型IL 1受体的细胞数量显著增加 ,染色加深 (P <0 0 5 )。阳性细胞的胞浆染色面积增大 ,突起染色的长度延长。结论　下丘脑室旁核和视上核在神经免疫调节过程中可能具有重要的作用。     

氨甲酰胆碱引起的促钠排泄与下丘脑TH—IR神经元活性的变化

目的：我们最近的实验发现大鼠侧脑室注射氨甲酰胆碱引起显著的促钠排泄作用,本工作同时还观察了下丘脑内不同脑区的儿茶酚胺能神经元活性的变化。方法和结果：氨甲酰胆碱注射后４０ｍｉｎ,下丘脑室旁核的腹侧和内侧小细胞部、内侧视前区、尾核、苍白球的酪氨酸羟化酶免疫反应（ｔｈｙｒｏｓｉｎｅｈｙｄｒｏｘｙｌａｓｅｉｍｍｕｎｏｒｅａｃｔｉｖｉｔｙ,ＴＨＩＲ）阳性细胞数减少,免疫反应染色强度降低;下丘脑室旁核的后部,下丘脑前区的后部、下丘脑室周核、弓状核、下丘脑外侧区的ＴＨＩＲ阳性细胞数增多,免疫反应染色强度增强。结论：侧脑室注射氨甲酰胆碱对脑内不同脑区的内源性儿茶酚胺能神经元分别有兴奋或抑制作用,其与促钠排泄的关系将在本文中讨论     

大鼠脑内血管的单胺能神经起源的观察──免疫组织化学研究

本研究采用直流电极单极损毁核团法及ＡＢＣ免疫过氧化物酶法,以酪氨酸羟化酶（ＴＨ）作为标记物,观察了２８只（分正常组、手术Ⅰ组、手术Ⅱ组、手术Ⅲ组）成年Ｗｉｓｔｅｒ大白鼠脑实质内血管的单胺能神经纤维的起始核团。正常组蓝斑区及脑桥网状结构内均可见大量密集的免疫反应阳性细胞体及交织成网的阳性纤维,端脑、间脑、中脑及脑桥各部血管壁上可见棕褐色的免疫反应阳性纤维;手术Ⅰ组损毁蓝斑,该区阳性细胞体及纤维消失,同时观察到端脑皮质、间脑、中脑及脑桥实质内血管壁上的阳性纤维数量明显减少;手术Ⅱ组同时损毁蓝斑及脑桥网状核,脑各部实质内血管的阳性纤维均不可见;手术Ⅲ组损毁脑桥网状核,端脑、间脑、中脑及脑桥实质内血管壁上仍可见棕褐色的阳性纤维。结果提示：脑实质内血管的单胺能神经纤维除主要起源于蓝斑外,还与脑桥网状结构有关。讨论了脑内血管的单胺能神经起源对脑实质内血管的单胺能神经及对脑内微循环的调控作用。     

孤束核参与刺激下丘脑室旁核的镇痛作用

本实验用电刺激鼠尾-嘶叫法测痛,观察电刺激下丘脑室旁核的镇痛效应,并采用核团损毁和核团内微量注射药物等方法分析其镇痛通路。实验结果如下:(1)电刺激下丘脑室旁核能产生明显的镇痛效应。同时,放射免疫测定发现脑干加压素含量升高。(2)损毁孤束核能取消刺激下丘脑室旁核的镇痛效应,但对基础痛阈无影响。(3)孤束核内微量注射加压素拮抗剂[d(CH_2)_5 TYr(Me)-AVP]60ng/0.6μl 和加压素抗血清0.6μl 都可明显对抗刺激下丘脑室旁核的镇痛效应。(4)直接在孤束核内微量注射加压素60ng/0.6μl,能模拟刺激下丘脑室旁核的镇痛效应。实验结果表明:电刺激下丘脑室旁核能产生镇痛效应,其机理之一可能是兴奋了下丘脑室旁核中加压素能神经元胞体,后者通过下行投射纤维在孤束核中释放加压素,影响孤束核神经元的活动,从而产生镇痛。     

Aldosterone-induced brain MAPK signaling and sympathetic excitation are angiotensin II type-1 receptor dependent

Angiotensin II (ANG II)-induced mitogen-activated protein kinase (MAPK) signaling upregulates angiotensin II type-1 receptors (AT(1)R) in hypothalamic paraventricular nucleus (PVN) and contributes to AT(1)R-mediated sympathetic excitation in heart failure. Aldosterone has similar effects to increase AT(1)R expression in the PVN and sympathetic drive. The present study was undertaken to determine whether aldosterone also activates the sympathetic nervous system via MAPK signaling and, if so, whether its effect is independent of ANG II and AT(1)R. In anesthetized rats, a 4-h intravenous infusion of aldosterone induced increases (P < 0.05) in phosphorylated (p-) p44/42 MAPK in PVN, PVN neuronal excitation, renal sympathetic nerve activity (RSNA), mean blood pressure (MBP), and heart rate (HR). Intracerebroventricular or bilateral PVN microinjection of the p44/42 MAPK inhibitor PD-98059 reduced the aldosterone-induced RSNA, HR, and MBP responses. Intracerebroventricular pretreatment (5 days earlier) with pooled small interfering RNAs targeting p44/42 MAPK reduced total and p-p44/42 MAPK, aldosterone-induced c-Fos expression in the PVN, and the aldosterone-induced increases in RSNA, HR, and MBP. Intracerebroventricular infusion of either the mineralocorticoid receptor antagonist RU-28318 or the AT(1)R antagonist losartan blocked aldosterone-induced phosphorylation of p44/42 MAPK and prevented the increases in RSNA, HR, and MBP. These data suggest that aldosterone-induced sympathetic excitation depends upon that AT(1)R-induced MAPK signaling in the brain. The short time course of this interaction suggests a nongenomic mechanism, perhaps via an aldosterone-induced transactivation of the AT(1)R as described in peripheral tissues.     

New data on the immunocytochemical localization of thyrotropin-releasing hormone in the rat central nervous system

An antiserum raised against the synthetic tripeptide pyroglutamyl-histidyl-proline (free acid) was used to localize thyrotropin-releasing hormone (TRH) in the rat central nervous system (CNS) by immunocytochemistry. The distribution of TRH-immunoreactive structures was similar to that reported earlier; i.e., most of the TRH-containing perikarya were located in the parvicellular part of the hypothalamic paraventricular nucleus, the suprachiasmatic portion of the preoptic nucleus, the dorsomedial nucleus, the lateral basal hypothalamus, and the raphe nuclei. Several new locations for TRH-immunoreactive neurons were also observed, including the glomerular layer of the olfactory bulb, the anterior olfactory nuclei, the diagonal band of Broca, the septal nuclei, the sexually dimorphic nucleus of the preoptic area, the reticular thalamic nucleus, the lateral reticular nucleus of the medulla oblongata, and the central gray matter of the mesencephalon. Immunoreactive fibers were seen in the median eminence, the organum vasculosum of the lamina terminalis, the lateral septal nucleus, the medial habenula, the dorsal and ventral parabrachial nuclei, the nucleus of the solitary tract, around the motor nuclei of the cranial nerves, the dorsal vagal complex, and in the reticular formation of the brainstem. In the spinal cord, no immunoreactive perikarya were observed. Immunoreactive processes were present in the lateral funiculus of the white matter and in laminae V-X in the gray matter. Dense terminal-like structures were seen around spinal motor neurons. The distribution of TRH-immunoreactive structures in the CNS suggests that TRH functions both as a neuroendocrine regulator in the hypothalamus and as a neurotransmitter or neuromodulator throughout the CNS.     

Galanin-like immunoreactivity in the chicken brain

The anatomical distribution of neurons containing galanin has been studied in the central nervous system of the chicken by means of immunocytochemistry using antisera against rat galanin. Major populations of immunostained perikarya were detected in several brain areas. The majority of galanin-immunoreactive cell bodies was present in the hypothalamus and in the caudal brainstem. Extensive groups of labeled perikarya were found in the paraventricular, periventricular, dorsomedial and tuberal hypothalamic nuclei, and in the nucleus of the solitary tract in the medulla oblongata. In the telencephalon, immunoreactive perikarya were observed in the preoptic area, in the lateral septal nucleus and in the hippocampus. The mesencephalon contained only a few galanin-positive perikarya located in the interpeduncular nucleus. Immunoreactive nerve fibers of varying density were detected in all subdivisions of the brain. Dense accumulations of galanin-positive fibers were seen in the preoptic area, periventricular region of the diencephalon, the ventral hypothalamus, the median eminence, the central gray of the brainstem, and the dorsomedial caudal medulla. The distributional pattern of galanin-immunoreactive neurons suggests a possible involvement of a galanin-like peptide in several neuroregulatory mechanisms.     

Central connections of the olfactory bulb in the goldfish,Carassius auratus

Summary The central connections of the goldfish olfactory bulb were studied with the use of horseradish peroxidase methods. The olfactory bulb projects bilaterally to ventral and dorsolateral areas of the telencephalon; further targets include the nucleus praeopticus periventricularis and a caudal olfactory nucleus near the nucleus posterior tuberis in the diencephalon, bilaterally. The contralateral bulb and the anterior commissure also receive an input from the olfactory bulb. Contralateral projections cross in rostral and caudal portions of the anterior commissure and in the habenular commissure. Retrogradely labeled neurons are found in the contralateral bulb and in three nuclei in the telencephalon bilaterally; the neurons projecting to the olfactory bulb are far more numerous on the ipsilateral side than in the contralateral hemisphere. Afferents to the olfactory bulb are found to run almost entirely through the lateral part of the medial olfactory tract, while the bulb efferents are mediated by the medial part of the medial olfactory tract and the lateral olfactory tract. Selective tracing of olfactory sub-tracts reveals different pathways and targets of the three major tract components. Reciprocal connections between olfactory bulb and posterior terminal field suggest a laminated structure in the dorsolateral telencephalon.     

Immunohistochemical Localization of C-RFamide, a FMRF-related Peptide, in the Brain of the Goldfish, Carassius auratus

Carassius RFamide (C-RFa) is a novel peptide found in the brain of the Japanese crucian carp. It has been demonstrated that mRNA of C-RFa is present in the telencephalon, optic tectum, medulla oblongata, and proximal half of the eyeball in abundance. Immunohistochemical methods were employed to elucidate the distribution of the peptide in the brain of the goldfish (Carassius auratus) in detail. C-RFaimmunoreactive perikarya were observed in the olfactory bulb, the area ventralis telencephali pars dorsalis and lateralis, nucleus preopticus, nucleus preopticus periventricularis, nucleus lateralis tuberis pars posterioris, nucleus posterioris periventricularis, nucleus ventromedialis thalami, nucleus posterioris thalami, nucleus anterior tuberis, the oculomotor nucleus, nucleus reticularis superior and inferior, facial lobe, and vagal lobe. C-RFa immunoreactive fibers and nerve endings were present in the olfactory bulb, olfactory tract, area dorsalis telencephali pars centralis and medialis, area ventralis telencephali, midbrain tegmentum, diencephalon, medulla oblongata and pituitary. However, in the optic tectum the immunopositive perikarya and fibers were less abundant. Based on these results, some possible functions of C-RFa in the nervous system were discussed.     

The organization of serotonin-immunoreactive neuronal systems in the brain of the crested newt,Triturus cristatus carnifex Laur.

Summary The distribution of serotonin (5-HT) immunoreactive structures has been investigated in the brain of the crested newt by means of indirect immunofluorescence, and unlabeled antibody peroxidase-antiperoxidase-complex (PAP) or biotin-avidin-system (BAS) techniques. In the newt, the bulk of the serotoninergic system extends from the raphe region of the medulla oblongata, through the isthmus, toward the mesencephalic tegmentum, and is characterized by pyriform neurons mainly located in a subependymal position, close to the midline. Also in the caudal hypothalamus, in addition to some 5-HT-positive adenohypophysial cells, many immunoreactive CSF-contacting neurons are found lining the paraventricular organ and the nucleus infundibularis dorsalis. A rich serotoninergic innervation was observed in the preoptic area and in the habenular complex. Concerning the telencephalon, immunopositive nerve fibers are encountered in the dorsal pallium, primordium hippocampi, striatum and olfactory bulbs. The general organization of serotoninergic systems in the newt brain exhibit close similarities to that described in higher vertebrates.     

Autoradiographic distribution of 125I calcitonin gene-related peptide binding sites in the rat central nervous system

Using autoradiographic method and 125I-Tyro rat CGRP as a ligand, receptor binding sites were demonstrated in the rat central nervous system. Saturation studies and Scatchard analysis of CGRP-binding to slide mounted tissue sections containing primarily cerebellum showed a single class of receptors with a dissociation constant of 0.96 nM and a Bmax of 76.4 fmol/mg protein. 125I-Tyro rat CGRP binding sites were demonstrated throughout the rat central nervous system. Dense binding was observed in the telencephalon (medial prefrontal, insular and outer layers of the temporal cortex, nucleus accumbens, fundus striatum, central and inferior lateral amygdaloid nuclei, most caudal caudate putamen, organum vasculosum laminae terminalis, subfornical organ), the diencephalon (anterior hypothalamic, suprachiasmatic, arcuate, paraventricular, dorsomedial, periventricular, reuniens, rhomboid, lateral thalamic pretectalis and habenula nuclei, zona incerta), in the mesencephalon (superficial layers of the superior colliculus, central nucleus of the geniculate body, inferior colliculus, nucleus of the fifth nerve, locus coeruleus, nucleus of the mesencephalic tract, the dorsal tegmental nucleus, superior olive), in the molecular layer of the cerebellum, in the medulla oblongata (inferior olive, nucleus tractus solitarii, nucleus commissuralis, nuclei of the tenth and twelfth nerves, the prepositus hypoglossal and the gracilis nuclei, dorsomedial part of the spinal trigeminal tract), in the dorsal gray matter of the spinal cord (laminae I-VI) and the confines of the central canal. Moderate receptor densities were found in the septal area, the "head" of the anterior caudate nucleus, medial amygdaloid and bed nucleus of the stria terminalis, the pyramidal layers of the hippocampus and dentate gyri, medial preoptic area, ventromedial nucleus, lateral hypothalamic and ventrolateral thalamic area, central gray, reticular part of the substantia nigra, parvocellular reticular nucleus. Purkinje cell layer of the cerebellum, nucleus of the spinal trigeminal tract and gracile fasciculus of the spinal cord. The discrete distribution of CGRP-like binding sites in a variety of sensory systems of the brain and spinal cord as well as in thalamic and hypothalamic areas suggests a widespread involvement of CGRP in a variety of brain functions.     

Identification of growth-hormone- and prolactin-containing neurons within the avian brain

Prolactin (PRL)- and growth-hormone (GH)-containing perikarya and fibers independent of the anterior pituitary gland have been reported to exist in the central nervous system of several mammalian species. The specific distributions of PRL- or GH-like neurons in the avian forebrain and midbrain, however, have not been reported. The objective of the study was to identify GH- and PRL-containing neurons in the hypothalamus and a few extrahypothalamic areas of two avian species. Brain and peripheral blood samples were collected from laying and broody turkey hens and ring doves. Broody turkey hens and doves had significantly higher plasma PRL concentrations compared with laying hens. Coronal brain sections were prepared and immunostained using anti-turkey GH and anti-chicken synthetic PRL antibodies. In turkey hens, the most dense GH-immunoreactive (ir) perikarya and fibers were found in hippocampus (Hp), periventricular hypothalamic nucleus, paraventricular nucleus, inferior hypothalamic nucleus, infundibular hypothalamic nucleus, medial and lateral septal area, and external zone of the median eminence (ME). In the ring dove, a similar pattern of distribution of GH-ir neurons was noticed at the brain sites listed above except that GH-ir fibers and granules were found only in the internal zone of ME and not in the external zone. In both turkeys and doves, the most immunoreactive PRL-ir perikarya and fibers were found in the medial and lateral septal area, Hp (turkey only), and bed nucleus of the stria terminalis pars magnocellularis. There were no apparent differences in the staining pattern of GH- or PRL-ir neurons between the laying and broody states in either species. However, the presence of GH-ir- and PRL-ir perikarya and fibers in several hypothalamic nuclei indicates that GH and PRL may influence parental behavior, food intake, autonomic nervous system function, and/or reproduction.