大鼠下丘脑部分核团形态学的测量及计算机三维重建

目的：系统地反映下丘脑有关核团的立体模式,为深入探讨下丘脑的功能提供形态学依据。方法：制作正常成年SD大鼠冷冻冠状连续切片,运用MAPGIS 6．0测量下丘脑弓状核、室旁核、腹内侧核、背内侧核的截面积、体积等相关数据,并用3DS MAX 5．0软件三维重建出下丘脑及核团的立体图像。结果：三维重建的立体图像逼真自然,能够流畅地旋转、缩放,可在任一角度观察其形态,任一平面切割行切面观察,图像空间毗邻及定位准确,三维测量获得了精确的解剖参数。结论：下丘脑及核团的计算机重建图像可从多个外科手术角度进行观察,为脑的立体定向研究及颅部外科手术提供重要参考资料。     

睫状神经营养因子对应激大鼠下丘脑、垂体精氨酸加压素含量的影响

目的：研究睫状神经营养因子（ＣＮＴＦ）对应激大鼠下丘脑、垂体精氨酸加压素（ＡＶＰ）含量及下丘脑ＡＶＰ阳性神经元的影响。方法：选用条件性足底电击应激大鼠模型，用放射免疫分析的方法观察双侧海马微量注射ＣＮＴＦ对应激大 下丘脑及垂体ＡＶＰ含量的影响，用免疫组织化学染色的方法结合光镜与图像分析观察下丘脑室旁核ＡＶＰ阳性神经元的变化。结果：应激大鼠下丘脑、垂体ＡＶＰ含量升高；下丘脑室旁核ＡＶＰ阳性神经元增多，染色变深，平均吸光度显著增加。给予ＣＮＴＦ的大鼠下丘脑、垂体ＡＶＰ含量明显降低；下丘脑室旁核ＡＶＰ阳性神经元减少，染色变浅，平均吸光度明显减少。结论：ＣＮＴＦ明显降低应激引起的下丘脑、垂体ＡＶＰ含量的升高。     

舌体三维动态分析与仿真

目的在中医舌诊客观化研究进程中,以二维舌图像及视频为基础进行分析所获得的舌体特征信息有限,制约了舌诊的客观化发展。为了形象地表达在观察真实舌体时所感知的三维动态信息,本文基于光度立体法实现对舌体的动态三维表面重建,进而获取舌体三维表面形态及动态特征信息。方法首先设计舌体动态信息采集系统,完成舌图像序列的采集;然后由采集的图像序列依次计算舌体表面的法向量和深度信息,得到深度网格模型,进而估计舌体颤动频率;最后基于渐变动画实现舌体运动仿真。结果该方法可较好地重建出舌体的表面形态,针对不同颤动频率的舌体,运动仿真结果可直观地展示舌体运动特征,从而为医生提供量化的诊断依据。结论基于光度立体法的舌体动态三维表面重建可以完成对舌体三维表面形态的重建及运动仿真。     

基于CT图像的眼部组织重建

以眼部组织CT图像为基础构建眼部组织三维模型,帮助医生从多方位观察眼部组织结构并对感兴趣区域进行定性和定量分析.我们提出了一种利用CT图像重建眼部三维结构的方法.通过图像分割和三维重建,构建了眼部组织的三维模型.并对计算机辅助测量眼眶容积的方法进行了改进.利用该方法重建了眼部各组织的三维模型,计算了眼眶容积.本方法建模速度比较快,建模比较精确.眼眶容积计算与目前使用方法相比,大量节省了医生的精力.     

心理应激雌性大鼠海马-下丘脑-垂体雌激素受体的变化

目的：探讨雌性大鼠心理应激状态下，海马-下丘脑-垂体雌激素受体（ER）的改变，进而阐明卵巢内分泌功能失调的机制。 方法: 采用声-光-电复合刺激作为心理应激制造大鼠卵巢内分泌功能失调模型；采用免疫组化方法和图像分析仪定量分析海马-下丘脑-垂体ER的表达。 结果： 采用声-光-电复合刺激雌性大鼠后，大鼠海马-下丘脑-垂体ER的表达下降。 结论： 心理应激雌性大鼠海马-下丘脑-垂体ER下降可能是卵巢内分泌功能失调的机制之一。     

一种基于大鼠颈髓连续切片的计算机三维重建方法

目的 以个人计算机(PC)为平台,探讨一种基于大鼠颈髓切片进行脊髓三维重建方法.方法 制作正常SD大鼠颈髓节段包埋蜡块,于颈髓标本四周进行外定位标记,Leica石蜡切片机进行连续横断切片,每切3张,用CANON数码相机对蜡块中的颈髓标本及其外定位标记进行摄片,获得连续切片图像.所得图像进行排序,裁切,转换为灰度图像并进行背景不均匀校正后,利用3D-DOCTOR软件对每张图像上的颈髓、颈髓灰质及定位孔进行边缘提取,利用定位孔对连续图像进行自动配准,三维表面重建后在PC机上进行任意角度观察、切割和测量.结果 利用大鼠颈髓连续切面图像重建得到大鼠颈髓白质和灰质,并对其进行测量,获得了表面积和体积等数据.结论 利用石蜡包埋和"硬"定位技术可以获得颈髓节段连续横断切面图像,进行三维重建并对重建结构进行自由观察和测量.     

大鼠小肠壁连续切片的三维重建

目的 在肠壁、微绒毛及肠腺3个观察水平对大鼠小肠进行三维重建,观察其内部各结构的三维形态学特征及空间位置关系.方法 正常SD大鼠1只,取小肠制作石蜡包埋标本,经连续切片、HE染色后,进行数字化图像采集;经图像拼接、预处理、配准、分割及三维重建等步骤后,观察各结构空间相互位置关系,并进行形态学指标测量.结果三维重建图像能够直观、立体地显示肠壁及肠壁内各结构(如动脉、静脉、淋巴管、微绒毛、肠腺等)的三维形态及相互空间位置关系.根据重建结果测量得到多项形态学指标,如微绒毛密度、平均高度,肠腺密度、体积.结论小肠黏膜下层与微绒毛内部存在丰富的血管网及淋巴管网,其排列方式与小肠的吸收及免疫功能密切相关.     

大鼠垂体后叶中神经降压素阳性神经纤维的起源

向垂体后叶注射WGA-HRP,进行逆行追踪并与免疫组织化学相结合研究了大鼠垂体后叶中神经降压素(NT)能神经纤维的起源。投射到垂体后叶的NT免疫阳性神经元胞体主要位于下丘脑室旁核小细胞部、室周区,环状核、室旁核大细胞亚核内侧部、视上核背侧部、穹窿后核及下丘脑前区、外侧区。弓状核内未见任何双标记神经元,从而否定了Goedert等用损毁的方法得出的大鼠垂体后叶中NT阳性神经纤维起源于弓状核的结论。一些室周双标记神经元位于室管膜内,距第三脑室腔很近,常挤在室管膜细胞之间。提示这些神元在监测脑脊液的化学变化,调节垂体后叶分泌方面起一定的作用。     

探索建立颅脑MRI图像、断层标本图像及三维重建图像的对比数据模型

目的利用计算机图像处理系统对颅脑主要重要结构进行三维成像,探索建立1套正常颅脑部MRI图像、断层标本及三维重建图像的数据对照计算机模型,为影像诊断及颅脑部手术定位提供形态依据。方法利用Microsoft Visual Studio将获得的MRI图像、断层标本图像及重建的三维图像建立数据模型。结果建立的数据模型提供了颅脑部正常解剖学影像学对比特点,构建了主要结构的三维立体模型图像,使抽象结构数字化、立体化、可视化,有助于对人脑的理解。结论本数据模型把颅脑结构的三维图像结合到标本MRI的对比图中,有利于初次接触颅脑断层的初学者。     

女性盆底可视化研究

目的：建立中国人体女性盆底部局部可视化数字模型。方法：应用中国女性数字化可视人体数据集，采用体绘制及面绘制重建方法，分别在P4微机和SGI工作站上对盆底部结构进行计算机三维重建及立体显示。结果：在P4微机上实现女性盆底部交互式三维可视化，在SGI工作站上重建了女性盆底部三维数字模型，三维重建图像能够清晰显示盆底部肌肉与骨性结构、膀胱、子宫及直肠等的三维解剖关系。结论：中国女性数字化可视人体数据集能够提供完整精确的断面数据，女性盆底三维交互可视化及数字模型准确反映该区域复杂的解剖结构及其空间毗邻关系，可为该区疾病的影像诊断及外科手术治疗提供形态学依据。     

Glucocorticoid receptors in brain and pituitary of the lactating rat

The female rat exhibits elevated corticosterone levels throughout lactation, suggesting a possible dampening of the sensitivity of adrenocortical negative-feedback processes during this period. Negative-feedback within the adrenocortical axis is, in large part, mediated by an enhanced hormone receptor signal at a number of glucocorticoid target sites, including the pituitary, hypothalamus, and hippocampus. In the study reported here we have measured glucocorticoid receptor binding capacity in soluble fractions prepared from these tissues, using an in vitro binding assay with [3H]dexamethasone as radioligand. We found that during at least the first two weeks of lactation the rat shows significantly decreased [3H]dexamethasone binding capacity in the hippocampus, with no change in pituitary or the hypothalamus during lactation. These data provide one possible mechanism whereby a critical target region for adrenocortical negative-feedback might be desensitized to circulating glucocorticoids, thus permitting the sustained elevation in pituitary-adrenal activity.     

High molecular weight immunoreactive basic fibroblast growth factor-like proteins in rat pituitary and brain

Four proteins immunologically related to basic fibroblast growth factor (bFGF) have been detected by Western blot analysis in the extract from rat anterior pituitary. Their apparent molecular weights are 29, 27, 18, and 14 kDa, respectively. A similar immunoreactive pattern has been observed in the rat tumor pituitary GH3 cell line. In the extracts from rat neurohypophysis, hypothalamus, hippocampus, striatum, olfactory tubercles, cerebellum, and cortex only the 29 kDa form is detectable in a significant amount.     

Comparative localization of corticotropin and corticotropin releasing factor-like peptides in the brain and hypophysis of a primitive vertebrate, the sturgeonAcipenser ruthenus L.

Summary The sturgeon is a primitive actinopterigian fish that, unlike modern teleosts, possess a portal vascular system that connects a true median eminence with the anterior pituitary as in mammals. The occurrence and localization of corticotropin and corticotropin releasing factor-like immunoreactivities were examined in the brain of the sturgeon (Acipenser ruthenus L.) by immunocytochemistry with antisera raised against synthetic non-conjugated human corticotropin, and rat/human corticotropin releasing factor. In the hypothalamus, corticotropin-immunoreactive parvicellular perikarya were found in the infundibular nucleus and in dendritic projections to the infundibular recess. In addition, ependymofugal corticotropin-immunoreactive fibres were found to terminate in the ventral hypothalamus. Corticotropin releasing factor-immunoreactive neurons were found in the rostral portion of the ventral hypothalamus (tuberal nucleus), and in the vicinity of the rostral aspect of the lateral recess. These cells projected to the dorsal hypothalamus, the ventral hypothalmus, the median eminence, the anterior and posterior telencephalon, the tegmentum mesencephali, and the pars nervosa of the pituitary. An affinitypurified UI antiserum failed to stain the sturgeon hypothalamus. Corticotrophs in the rostral pars distalis of the pituitary were also corticotropin-immunoreactive. In the neurointermediate lobe, only about 50% of cells of the pars intermedia appeared to be corticotropin-positive, the rest appeared unstained. These results suggest that the presence of corticotropin-like and corticotropin releasing factor-like peptides in the brain is a relatively early event in vertebrate evolution, already occurring in Chondrostean/Actinopterigian fishes, as exemplified byA. ruthenus.The close spatial relationship between corticotropin releasing factor immunoreactivity and corticotropin immunoreactivity in the ventral hypothalamus ofA. ruthenus supports a possible interaction between the two systems in that area of the sturgeon brain. The pars intermedia might be an important site for corticotropin synthesis, even though the possibility cannot be excluded that the antiserum was recognizing the proopiomelanocortin molecule. The occurrence of corticotropin releasing factor immunoreactivity in the region of median eminence/pars intermedia of the sturgeon suggests that the sturgeon corticotropin releasing factor might regulate the adenohypophyseal release of proopiomelanocortin products in the same manner as in other vertebrates. The presence of extrahypothalamic corticotropin releasing factor-immunoreactive projections suggests further neuromolulatory functions for this peptide inA. ruthenus.     

Distribution of beta-endorphin and related peptides in the hypothalamus and pituitary.

β-Endorphin and its precursors, β-lipotropin and pro-opiocortin, in the pituitary and hypothalamus of the rat, were studied by means of radioimmunoassays with antisera to β-endorphin, β-melanocyte stimulating hormone and adrenocorticotropin. Gel filtration chromatography in combination with radioimmunoassay revealed the existence of β-endorphin, β-lipotropin and pro-opiocortin in all the tissues studied, with the highest concentration in the posterior-intermediate lobe of the pituitary gland. Great variation was observed in the relative amounts of these three β-endorphin-like immuno-reactive peptides in different regions. The ratio of β-endorphin to β-lipotropin is highest in the hypothalamus, is less in the posterior intermediate pituitary lobe and lowest in the anterior pituitary lobe. A β-melanocyte-stimulating hormone-like immunoreactive peptide, which is larger than porcine β-melanocyte-stimlating hormone and smaller than β-lipotropin, was detected in the posterior-intermediate lobe but not in the anterior lobe of the pituitary.The results suggest that the pro-opiocortin may act mainly as a precursor of adrenocorticotropin in the anterior pituitary and that β-endorphin may act mainly in the intermediate lobe of the pituitary where there is conversion of β-lipotropin to β-endorphin and the β-melanocyte-stimulating hormone-like immunoreactive peptide.     

FMRFamide-like immunoreactivity in the brain and pituitary of the goldfish, Carassius auratus.

The distribution of FMRFamide-like immunoreactivity was determined in the brain and the pituitary of the goldfish, Carassius auratus. Immunoreactive perikarya were observed in the olfactory nerve, nucleus entopeduncularis, nucleus anterioris periventricularis, nucleus posterioris periventricularis, lateral part of the nucleus lateralis tuberis pars posterioris, midbrain tegmentum, and medulla oblongata. Immunoreactive fibers were widely distributed in the brain, in particular in the ventral telencephalon and the hypothalamus. A few immunoreactive nerve fibers were observed in the pituitary. The findings are discussed in relation to male sexual behavior and the involvement of FMRFamide-like peptide in pituitary functions in the goldfish.     

Autoradiographic distribution of pituitary adenylate cyclase activating polypeptide (PACAP) binding sites in the rat brain

Distribution of pituitary adenylate cyclase activating polypeptide (PACAP) binding sites was investigated in the rat brain and pituitary gland by means of in vitro autoradiography. High densities of specific [125I]PACAP binding were observed in the anterior pituitary, hippocampus (CA1-4 and dentate gyrus) and in the superior colliculus. Moderate to high labeling was observed in the periaqueductal gray matter, substantia nigra pars compacta, and in the habenula. The hypothalamus, thalamus, ventral tegmental area (VTA), mammillary body and medial geniculate body were moderately labeled. The present results support possible actions of PACAP on the pituitary functions, and further suggest that PACAP is a neurotransmitter/neuromodulator in the central nervous system.     

Co-expression of vasopressin and androgen-binding protein in the rat hypothalamus

In previous studies we have observed the expression of androgen binding protein (ABP) in the rat hypothalamo-neurohypophysial system. With immunocytochemical double staining we found partial co-localization with oxytocin. In the present study we used antibodies to the anti-diuretic hormone arginine vasopressin (AVP) for co-localization with ABP in the rat hypothalamus. Both antigens were seen in the magnocellular paraventricular and supraoptic nuclei. Dense fiber networks with varicosities containing both AVP and ABP immunoreactivity were visible throughout the hypothalamus, the median eminence and in the posterior pituitary lobe. Double immunostaining revealed also co-existence in the parvocellular portion of the paraventricular nucleus and in the suprachiasmatic nucleus. ABP immunoreactive neurons in the preoptic region were devoid of AVP staining, AVP neurons in the bed nucleus of the stria terminalis stained only occasionally for ABP. We conclude that both the magnocellular and the parvocellular hypothalamic vasopressin systems are capable of expressing the steroid binding globulin, which is probably subject to axonal transport, along with the peptide hormone. Intrahypothalamic expression of ABP may be among the mechanisms necessary for rapid actions of steroids on hypothalamic neuroendocrine systems.     

Origin of the nerve endings in the surface zone of the median eminence of the rat hypothalamus

Summary In order to study the origin of the nerve endings in the surface zone (zona palisadica) of the median eminence and the proximal part of the pituitary stalk, experiments were designed to determine the extent of the smallest region of the brain, isolation of which does not result in terminal degeneration in this zone. Various hypothalamic areas were partially or totally separated from the brain by means of a stereotaxically manipulated bayonet-shape knife and the zona palisadica was examined for secondary degeneration of axon terminals under the electron microscope. If the medial basal hypothalamus, including the suprachiasmatic area was disconnected from the rest of the brain, degenerated nerve endings do not occur in the palisade zone. Axon degeneration is observed if any part of the medio-basal area was separated from the median eminence or became necrotic. — These findings indicate that the nerve terminals in the zona palisadica arise exclusively from neurons in the medial basal hypothalamus, and that fibers of other origin do not terminate in this zone. The present observations support the assumption that the hypothalamic releasing (and inhibiting) factors are produced by, and the neural control of the anterior pituitary is exercised over a short final neuronal link, localized in the medial basal hypothalamus.