DNA fragmentation factor 45 knockout mice exhibit longer memory retention in the novel object recognition task compared to wild-type mice

Apoptosis is an important process in the development and function of the central nervous system (CNS). To study the role of DNA fragmentation factor 45 (DFF45/ICAD) in CNS function, we previously generated DFF45 knockout mice. We found that whereas they exhibit apparently normal CNS development, DFF45 knockout mice exhibit an increased number of granule cells in the dentate gyrus and enhanced spatial learning and memory compared to wild-type mice in a Morris water maze test. In this study, we examined the performance of the DFF45 knockout mice in a novel object recognition task to measure short-term nonspatial memory that is believed to depend on the hippocampal formation. Both wild-type and DFF45 knockout mice exhibited novel object recognition 1 h posttraining. However, whereas wild-type mice no longer did so, DFF45 knockout mice were still able to differentiate the novel versus the familiar object 3 h posttraining. The longer memory retention in DFF45 knockout mice did not last up to 24 h as neither wild-type nor DFF45 knockout mice demonstrated novel object recognition 24 h posttraining. These results suggest that a lack of DFF45 facilitates hippocampus-dependent nonspatial memory, as well as hippocampus-dependent spatial memory.     

壳聚糖纳米颗粒包裹对鼠白细胞介素2基因表达和调节小鼠免疫效应的影响

本实验制备壳聚糖纳米颗粒 (CNP) ,包裹小鼠白细胞介素 2基因 (mIL 2 )真核表达质粒 (VRMIL 2 ) ,肌注接种 2 1d昆明小鼠 ,观察mIL 2基因体内表达及其对免疫应答和免疫保护的影响。实验结果发现 :CNP包裹VRMIL 2注射小鼠血液中IgG、IgM和IgA不同程度地增多 ,均显著高于CNP包裹空白质粒组 (P <0 .0 5 ) ;其血清中IL 2、IL 4和IL 6的含量明显升高 ,与对照组差异显著 (P <0 .0 5 ) ;外周血液的白细胞和淋巴细胞数量也较对照组显著增加。免疫后 35d以大肠杆菌口服攻毒实验小鼠 ,检测发现 :CNP包裹VRMIL 2组小鼠的上述免疫指标除中性粒细胞外均显著多于对照小鼠 ,VRMIL 2接种小鼠均健康存活 ,而对照小鼠均发病 ;尽管CNP包裹VRMIL 2接种小鼠的体液和细胞免疫指标与未包裹VRMIL 2免疫鼠差异不显著 (P >0 .0 5 ) ,但剂量仅为后者的 1/ 5。这些结果表明 :壳聚糖纳米颗粒包裹VRMIL 2可显著提高外源IL 2基因体内表达水平 ,明显增强体液和细胞免疫水平的效应 ,增强对大肠杆菌的抗病力 ,提示壳聚糖纳米颗粒包裹IL 2基因可明显增强动物的体液和细胞免疫 ,可作为有效的抗感染免疫调节剂。     

Hippocampal neuron and synaptophysin-positive bouton number in aging C57BL/6 mice

A loss of hippocampal neurons and synapses had been considered a hallmark of normal aging and, furthermore, to be a substrate of age-related learning and memory deficits. Recent stereological studies in humans have shown that only a relatively minor neuron loss occurs with aging and that this loss is restricted to specific brain regions, including hippocampal subregions. Here, we investigate these age-related changes in C57BL/6J mice, one of the most commonly used laboratory mouse strains. Twenty-five mice (groups at 2, 14, and 28–31 months of age) were assessed for Morris water-maze performance, and modern stereological techniques were used to estimate total neuron and synaptophysin-positive bouton number in hippocampal subregions at the light microscopic level. Results revealed that performance in the water maze was largely maintained with aging. No age-related decline was observed in number of dentate gyrus granule cells or CA1 pyramidal cells. In addition, no age-related change in number of synaptophysin-positive boutons was observed in the molecular layer of the dentate gyrus or CA1 region of hippocampus. We observed a significant correlation between dentate gyrus synaptophysin-positive bouton number and water-maze performance. These results demonstrate that C57BL/6J mice do not exhibit major age-related deficits in spatial learning or hippocampal structure, providing a baseline for further study of mouse brain aging.     

Differentiation of extracellular matrix in the cellular cartilage ("Zellknorpel") of the mouse pinna

Summary Differentiation of cellular cartilage was studied in the mouse pinna with particular reference to matrix material. Fixation of glycosaminoglycans was performed by the use of acridine orange and elastin was identified by staining thin sections with tannic acid and uranyl acetate.Condensation of mesenchymal cells (prechondroblasts) initiates the formation of a blastema of cartilaginous tissue at postnatal day 4. The synthesis of acidic glycosaminoglycans begins at postnatal day 8 when prechondroblasts transform to chondroblasts. Glycosaminoglycans can be detected within secretory vesicles of chondroblasts at postnatal day 8, in the extracellular space at postnatal day 13. Delicate collagen fibrils and elastic fiber microfibrils are seen between prechondroblasts and chondroblasts. Deposition of elastin begins at postnatal day 11. A network of elastic fibers and lamellae is formed, which replaces both collagen fibrils and elastic fiber microfibrils. In the interstice of mature cellular cartilage only elastin and proteoglycans are present (postnatal day 21).These findings indicate that cellular cartilage represents an independent kind of supporting tissue, which may serve as a progenitor of hyaline or elastic cartilage (transitional cellular cartilage) but does not differentiate from hyalin cartilage.With financial support from the Hochschuljubiläumsstiftung der Stadt Wien. Part of this work has been presented at the 3. Arbeitstagung der Anatomischen Gesellschaft, Würzburg, 6.-8. 10. 1982     

慢性癫痫模型动物海马内GABA能神经元的超微结构改变

用马桑内酯诱发小鼠性性癫痫模型，借助免疫电镜方法对海马的ＧＡＢＡ能神经元的超微结构进行观察，可见小鼠海马内ＧＡＢＡ免疫反应阳性神经元弥散分布于除锥体细胞层和颗粒细胞层外的各部。慢性癫痫上鼠海马内的ＧＡＢＡ免疫反应性神经元胞体和末梢均呈现程度不同的结构损伤，包括线粒体肿胀，细胞器崩解和神经末梢变性，ＧＡＢＡ样轴突末梢可与免疫反应阴性的树突构成传出性轴－树突触，也可接受免疫反应阴性轴末梢的传入性轴－轴     

Ectopic granule cell layer in mouse cerebellum after methyl-azoxy-methanol (MAM) treatment

Summary Previous results from our laboratory (Bejar et al. 1985) indicated that a single injection in mouse pups of the antimitotic/mutagenic agent methylazoxymethanol at postnatal day 5 typically produces hypogranular cerebella with no changes in foliation, in contrast to the severe alterations observed after the more usual injection on the day of birth. Here we report that injection of a higher dose (30 mg/kg) of methylazoxymethanol, always at postnatal day 5, leads to the additional presence of a ectopic cell layer in adult cerebellum. Immunostaining with several antibodies recognizing cell specific proteins ruled out the possibility that these ectopic cells were glial and electron microscopy indicated that they were morphologically mature granule cells. In the molecular layer of other cerebellar areas and apparently unrelated with granule cell ectopia, ectopic Golgi epithelial cells were observed. The reason for the presence of these ectopic cells of different type in the molecular layer was discussed in relation with analogous ectopias obtained by other means.     

饮酒对小鼠睾丸生精小管一氧化氮合酶、增殖细胞核抗原表达及细胞凋亡影响的研究

目的　探讨酒精对小鼠睾丸的组织结构、内皮型一氧化氮合酶 (eNOS)、增殖细胞核抗原 (PCNA)及细胞凋亡的影响。　方法　用 5 %、10 %及 15 % 3种不同浓度的酒精作用于 2 2d龄小鼠 ,取睾丸做石蜡切片、HE染色 ;用免疫组织化学方法检测睾丸eNOS、细胞增殖的变化 ;TUNEL法检测细胞凋亡的变化 ,并进行统计学分析。　结果　随着酒精浓度的增大 ,睾丸组织结构发生明显改变 ,生精小管的直径逐渐减小 ,eNOS阳性细胞面积密度逐渐增大 ,单位面积内PCNA阳性细胞和凋亡细胞数目增加 ,高浓度酒精组与其他组差异极显著 (P <0 0 1)。　结论　酒精可使生精小管的直径变小 ,eNOS及PCNA表达增强 ,凋亡细胞增加并随酒精浓度的增大而变化加重。这可能是过量饮酒导致生精细胞减少 ,生殖能力降低的重要因素。     

Allergen-dependent CD14 modulation and apoptosis in monocytes from allergic patients

BACKGROUND: CD14 is a most important monocyte surface molecule. Recently, it has been reported that there is an important relationship between CD14 and immunoglobulin E, and that regulation of CD14 expression is an effector mechanism mediating apoptosis of monocytes. OBJECTIVE: The present study was designed to determine whether specific allergens were able to modulate CD14 expression and apoptosis by monocytes from allergic patients or whether specific immunotherapy (IT) might affect these processes. METHODS: One group of adult allergic asthmatic patients had received IT for the previous 3 years. Another similar group was not treated with IT. We challenged peripheral blood monocytes from both groups of asthmatic patients in vitro with the specific allergen that produced clinical symptoms in asthmatic patients. The cells were also challenged with allergen to which the patients were not sensitive. Monocytes from normal subjects were also challenged with allergens. Expression of CD14 on the monocyte surface was analyzed by flow cytometry, and soluble CD14 (sCD14) in culture supernatant by enzyme-linked immunosorbent assay. The three groups of subjects were challenged with allergens, and apoptosis was analyzed by flow cytometry. RESULTS: When monocytes from non-IT-treated asthmatic patients were cultivated with the allergens to which the patients were sensitive, a significant up-regulation on the monocyte surface was observed compared with results from the healthy group (P < 0.003) and from the IT asthmatic group (P < 0.003). A significantly higher sCD14 level was observed in the culture supernatant of the monocytes from the IT asthmatic group were observed compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (P < 0.001). A significantly higher apoptosis level was observed in monocytes from the IT asthmatic group compared with those from the healthy group (P < 0.001) and those from the non-IT asthmatic group (<0.001). CONCLUSIONS: We present evidence that the expression of CD14 on the surface of monocytes and the apoptosis of the same cells can be modulated by an allergen-dependent mechanism. These processes can be affected by IT.     

Morphological characteristics of cultured olfactory bulb cells

Cultured olfactory bulb cells from embryonic mice had ultrastructural characteristics similar to those of many cell types in the intact adult mouse olfactory bulb. Identified cultured cells included mitral/tufted cells, granule cells, short-axon cells, and fibrous and protoplasmic astrocytes. Cultured neurons were found as individual cells, clusters or aggregates. Clusters consisted of a loose array of neurons that appeared to be densely interconnected by neurites. However, few neurites or fascicles emanated from clusters to adjoining areas. Aggregates consisted of many small, usually rounded, neurons piled on top of one larger neuron, or on more than one, with typically many neurites and fascicles projecting to adjacent aggregates, clusters or individual neurons. Neurites of cultured olfactory bulb cells were well developed, and some were several millimeters long. Synapses were very prominent in these cultures, especially in aggregates, clusters, and fascicles. Electron-lucent, dense-core, and coated vesicles were present. Polarity, shape, and length of the long axis (size) of 815 cultured neurons, identified by positive anti-microtubule-associated protein 2 staining, were documented. Cultured neurons varied in size from 9 to 27 m, with an average size of 16 m. Elliptical bipolar (35%), triangular multipolar (21%), and round unipolar (15%) were the most common polarity/shape combinations found in culture. Multipolar, triangular, triangular multipolar, and elliptical bipolar cells increased in size with increasing age of culture. The relative proportions of triangular, multipolar, elliptical multipolar, and triangular multipolar cells decreased, whereas the relative proportions of round, unipolar, and round unipolar cells increased with increasing age of culture. These changes in population subtypes and cell size may indicate continued differentiation and maturation of cultured neurons.     

Standard atlas space for C57BL/6J neonatal mouse brain

A standard atlas space with stereotaxic co-ordinates for the postnatal day 0 (P0) C57BL/6J mouse brain was constructed from the average of eight individual co-registered MR image volumes. Accuracy of registration and morphometric variations in structures between subjects were analyzed statistically. We also applied this atlas coordinate system to data acquired using different imaging protocols as well as to a high-resolution histological atlas obtained from separate animals. Mapping accuracy in the atlas space was examined to determine the applicability of this atlas framework. The results show that the atlas space defined here provides a stable framework for image registration for P0 normal mouse brains. With an appropriate feature-based co-registration strategy, the probability atlas can also provide an accurate anatomical map for images acquired using invasive imaging methods. The atlas templates and the probability map of the anatomical labels are available at .