侧脑室注射东莨菪碱和酚妥拉明对幼兔分辨学习的影响

目的 探讨东莨菪碱和酚妥拉明对幼兔分辨学习的影响。方法 将30只比利时纯种幼兔从生后13日龄随机分为三组：东莨菪碱组、酚妥拉明组和生理盐水对照组，观察不同日龄各组幼兔的分辨学习能力。结果 幼兔分辨学习的正确反应一般始于生后15日龄。侧脑室注射东莨菪碱对16日龄以前幼兔分辨学习无明显影响，对17日龄以后幼兔分辨学习产生明显抑制作用。侧脑室注射酚妥拉明对13—23日龄幼兔分辨学习均有明显抑制作用。结论 幼兔生后发育过程中学习能力的发展具明显的阶段性，其原因可能与神经递质系统的发育成熟有关。     

大鼠眼上直肌神经的生后发育

取生后两天、两周和两月的雄性Ｗｉｓｔａｒ大鼠双眼上直肌，进行硝酸银染色和乙酰胆碱酯酶染色，用光镜观察大鼠眼上直肌神经在生后的发育情况。在大鼠生后两天时，动眼神经的分支从眼上直肌的中后三分之一交界处由眶面进入该肌，它向该肌的球面区发出细小的神经纤维束，这些神经束抵达同一条肌纤维上。眶面层神经纤维细小，单条并且平行于肌纤维方向走行。此时，眼上直肌对乙酰胆碱酯酶染色着色浅，反应区未形成某一特定轮廓，说明此时运动神经的发育是不成熟的。在生后两周时，动眼神经的分支开始向眼上直肌的眶面层发出神经纤维；球面区中的神经纤维有明显的粗细两种。这时眼上直肌中的运动神经轴索对乙酰胆碱酯酶染色反应，出现葡萄状运动神经末梢及斑点状运动终板的雏形。生后两月时，眼上直肌中出现了肌梭及典型的葡萄状运动神经末梢和斑点状运动终板。生后两周是大鼠睁眼初期，由此可见，大鼠从闭眼至睁眼的时期，是运动神经发育的关键时期，此时，运动神经形成一些特定神经末梢，而睁眼后运动神经的发育主要在此基础上运动神经末梢日趋完善和成熟。     

大鼠生后发育期间胃肠道IAPP免疫反应细胞的分布

用免疫组织化学ＰＡＰ法显示正常Ｗｉｓｔａｒ大鼠生后发育期间胃肠道ＩＡＰＰ免疫反应细胞，观察其形态和分布。结果表明，ＩＡＰＰ－ＩＲ细胞随生后发育而发生变化。生后１ｄ，ＩＡＰＰ－ＩＲ细胞即可见于胃肠道各段。１８ｄ时在胃体部较多，４５ｄ及成年时小肠各段较多，ＩＡＰＰ－ＩＲ细胞位于上皮细胞间及固有膜结缔组织中。本实验结果提示，大鼠胃肠道各段ＩＡＰＰ－ＩＲ细胞在个体生后继续发生变化。本文对上述结果可能的生物     

Development of the NADPH-diaphorase-positive neurons in the sympathetic ganglia

Changes in the distribution of NADPH-diaphorase (NADPH-d) were studied in neurons of the superior cervical ganglion (SCG), stellate ganglion (SG) and celiac ganglia (CG) in newborn, 10-, 20-day-old, 1-month-old, 2-month-old and 6-month-old rats, mice and kittens. NADPH-d-positive neurons were revealed in all sympathetic ganglia in kittens but not in rodents from birth onwards. In kittens, the largest population of NADPH-d-positive cells was found in the SG, the smallest in the SCG (<1%) and we observed only a few cells in the CG. The proportion of NADPH-d-positive cells in the SG increased from 3.1±0.15% in newborn kittens to 9.3±0.63% in 20-day-old animals and decreased further from 8.1±0.75% in 30-day-old kittens to 3.4±0.54% in 2-month-old animals. The content of NADPH-d-positive cells in the CG and SCG did not change during development. There were no differences in cross-sectional area between neurons located in different ganglia of animals from the same age group under study. We conclude that the development of NADPH-d-positive neurons in different sympathetic ganglia has its own time dynamics and is completed by the end of the second month of life.     

Changes of synapsin I messenger RNA expression during rat brain development

Synapsin I is a synaptic phosphoprotein that is involved in the short-term regulation of neurotransmitter release. In this report we present the first extensive study of the developmental expression of its corresponding messenger ribonucleic acid (mRNA) by in situ hybridization and northern blot analysis in rat brain. Synapsin I mRNA showed pronounced differences in expression in different brain regions during postnatal development. The early expression of synapsin I mRNA in ontogenetically older regions such as the thalamus, the piriform cortex and the hippocampus coincides with the earlier maturation of these regions, in contrast to its later expression in ontogenetically younger areas such as the cerebellum and the neocortex. An intriguing expression pattern was found in the hippocampus. In all hippocampal subregions synapsin I mRNA expression increased from postnatal day (PND) 1 to 17. After PND 17, however, there was a marked dissociation between persisting high expression levels in CA3 and the dentate gyrus and a strong decline in synapsin I mRNA expression in CA1. The persistence of synapsin I in some adult rat brain regions indicates that it plays a part in synapse formation during plastic adaption in neuronal connectivities.     

Single nephron glomerular filtration rate ratios of superficial,intercortical and juxtamedullary nephrons in rats during development

Summary In 20, 40 and 60-day-old rats the filtration rate was studied, using Baines modification of Hanssen's Na₄Fe(¹⁴CN)₆ method enabeling the determination of single nephron glomerular filtration rate (SNGFR) ratio between superficial (S), intercortical (I) and juxtamedullary (J) nephrons. The proximal tubule lengths were determined as well. A close correlation was obtained between age and S/I, I/J and S/J of proximal tubule lengths and between age and I/J, S/J¹⁴C-activities of ferrocyanide. Presented findings confirm the data on the increasing role of superficial nephrons in the course of postnatal development of rat.     

Scanning electron microscopic investigations of the human umbilical artery intima

Summary Umbilical cord arteries were investigated using a scanning electron microscope using different methods of preparation: Perfusion of one artery under pressure from a 100 cm water column caused artefacts and the preparatory work took at least 10 min after delivery. To shorten this time fully patent umbilical cords were double clamped and fixed immediately after birth. However, the removal of blood after fixation caused the endothelial layer to be lost. Therefore umbilical cords were double clamped, snap frozen and stored in liquid nitrogen until preparation. The endothelial lining of the fully patent umbilical artery at birth is composed of longitudinally arranged, spindleshaped cells, connected by cellular junctions. The basement membrane contains numerous gaps. Because of these gaps postnatal vasoconstriction causes herniation of the subendothelial myofibroblasts forming subendothelial vacuoles. The vacuoles produce displacement of the endothelial cell cytoplasm towards the vascular lumina resulting in protuberances and blebs on the endothelial cells. Rupture of vacuoles leads to crater-like injuries.Beneath the basement membrane a thin layer of myofibroblasts is arranged longitudinally. Oblique or transversely ordered bundles of myofibroblasts are interposed at wide and irregular intervals. These transverse bundles are able to trigger localized contraction rings called folds of Hoboken, the initial stage of postnatal arterial closure.     

Ontogeny of NADPH-diaphorase in rat forebrain and midbrain

 This study characterizes the developmental expression of NADPH-diaphorase from embryo to adulthood in the forebrain, midbrain and cerebellum of rat brain via histochemical staining. On embryonic day 12 no neurons stained. Labeling was observed in certain nuclei from E15 through the postnatal period to adulthood. Labeling in neurons increased or maintained a constant level with increased age. The embryo demonstrated substantial labeling in neurons of the caudate putamen, bed nucleus of the stria terminalis, preoptic area, lateral hypothalamic area, paraventricular thalamic nucleus, ventromedial hypothalamic nucleus, magnocellular nucleus posterior commissure, and periaqueductal central gray. Additional neuronal labeling was observed postnatally in the olfactory bulb, cerebral cortex, amygdala, various nuclei of the thalamus, interpeduncular nucleus, linear nucleus of the raphe, pretectal area and superior colliculus. In the cerebellum, labeling appeared only after P14 in cells of the molecular cell layer and granular cell layer. The sizes of labeled neurons developed significantly from P4 to P14 in several nuclei. The distinctive temporal and spatial expression pattern of NADPH-diaphorase implies that the NO/cGMP system may play an important role in physiological and developmental functions. Accepted: 8 September 1997     

EPDS在产后抑郁筛查中应用

本研究共纳入１６７例在北医大一院产科病房住院分娩的产妇，所有产妇均评定了Ｅｄｉｎｂｕｒｇｈ产后抑郁量表（ＥＰＤＳ）。对部分产妇同时评定了Ｚｕｎｇ氏抑郁量表和Ｈａｍｉｔｌｏｎ抑郁量表。结果表明ＥＰＤＳ之灵敏度、特异性及总效率均令人满意。与Ｚｕｎｇ氏量表相比，ＥＰＤＳ的效度更高，是比较理想的产后抑郁筛查工具。