Peripheral lipopolysaccharide administration impairs two-way active avoidance conditioning in C57BL/6J mice

Peripheral administration of lipopolysaccharide (LPS) or interleukin-1 (IL-1) may lead to alterations of CNS function and behavioral changes designated "sickness behavior." Further, some experiments show evidence of LPS- and cytokine-mediated alterations in learning and memory. The current series of experiments examined the effects of a single or repeated intraperitoneal LPS injections, at a number of doses and time points before or after test sessions, on behavior in a two-way active avoidance conditioning paradigm. Subjects were able to avoid the mild shock stimulus, escape it, or fail to respond to it. Subjects treated with LPS at many, but not all, of the time points sampled showed impaired learning, by exhibiting significantly fewer avoidance responses than controls. Furthermore, an LPS-induced increase in non-cued inter-trial interval crossings was observed during the later days of testing, suggesting that a greater percentage of their avoidance responses was not conditioned and their behavior was less efficient. Taken together, the results suggest that LPS-treated animals showed a diminished association between conditioned stimulus (CS) and unconditioned stimulus (US). These results support the theory that peripheral immune stimuli may induce deleterious effects on learning, and extend the work to a negatively reinforced operant procedure.     

肺炎衣原体感染致C57BL/6J小鼠内皮功能异常

目的：研究肺炎衣原体感染对C57BL/6J小鼠主动脉内皮依赖舒张反应及动脉粥样硬化形成的影响。方法：32只C57BL/6J小鼠分为肺炎衣原体感染并胆固醇饲料喂养组、胆固醇饲料喂养组、肺炎衣原体感染组和对照组，喂养24周，取主动脉弓标本分析动脉粥样硬化斑块面积，远端胸主动脉作血管舒张功能测定，血样品作血脂、一氧化氮水平及内皮素浓度测定。结果：肺炎衣原体感染并胆固醇饲料喂养组、胆固醇饲料喂养组和肺炎衣原体感染组乙酰胆碱引起的动脉平均最大舒张百分数明显低于对照组(P＜0.01)，且一氧化氮水平也较低，单纯肺炎衣原体感染小鼠无明显动脉粥样硬化形成。结论：肺炎衣原体感染可损害C57BL/6J小鼠动脉内皮功能，一氧化氮途径可能参与其发展。     

Effects of cyclosporine A on the process of vascularization of freely transplanted islets of Langerhans

We studied in vivo the effect of cyclosporine A (CsA) on both pancreatic islet vascularization and microvascular perfusion using intravital fluorescence microscopy and the dorsal skinfold chamber model in Syrian golden hamsters. Syngeneic transplantation was performed in order to exclude allograft- or xenograft-induced microvascular alterations. To study the effect of CsA on islet angiogenesis and vascularization, animals received 20 mg/kg CsA daily from day 0 until day 14 after transplantation (group A). To study toxic effects of CsA on islet microcirculation, the grafts were allowed to vascularize without immunosuppression, and 20 mg/kg CsA was given daily from day 10 until day 20 after transplantation (group B). Quantitative analysis of the process of islet vascularization in group A revealed a functional capillary density (FCD) of 515.6±72.7 cm^–1 at day 6 after transplantation without further increase until day 14 (504.3±16.7 cm^–1). Islet transplants which were not treated with CsA during the process of angiogenesis/vascularization (group B) demonstrated a slightly but significantly (P<0.05) higher FCD (604.7±42.5 cm^–1) at day 14 after transplantation, indicating slightly improved vascularization when compared to transplants of group A. Additional CsA treatment of these islet grafts until day 20 did not induce derangements of microvascular perfusion (601.2±67.0 cm^–1), indicating that the immunosuppressive, drug has no toxic/detrimental effects on the transplants nutritional blood supply. We conclude that CsA only slightly alters the process of final vascularization of freely transplanted islets, and does not deteriorate nutritive perfusion of completely vascularized grafts.     

复方紫杉醇注射液对 C57BL/6小鼠Lewis肺癌的作用研究

目的:研究复方紫杉醇注射液对C57BL/6小鼠Lewis肺癌的作用及其机制。方法:60只C57BL/6小鼠按体重随机分为5组,每组12只,移植皮下接种Lewis细胞。在接种后24小时,对照组给予生理盐水;实验组分别给予紫杉醇注射液大、小两种剂量,复方紫杉醇注射液大、小两种剂量,各组均腹腔注射,连续5天。停药后第6天脱颈处死动物,计算抑瘤率;用HE染色光镜观察细胞形态学的变化;用流式细胞仪(FCM)检测研究复方紫杉醇注射液诱导肿瘤细胞凋亡以及对肿瘤细胞周期的影响。结果:复方紫杉醇注射液大、小剂量组对荷瘤鼠Lewis肺癌有明显的抑制作用,且各剂量组均可诱导Lewis细胞凋亡,与对照组比较有显著性差异(P<0.05);而对细胞周期的影响不太明显。结论:复方紫杉醇注射液对移植于C57BL/6小鼠的Lewis肺癌具有明显的抑制作用,其机制可能与诱导肿瘤细胞凋亡有关。     

Comparison of the N- and O-linked glycopeptides of lymph node cells from C57 BL/6 lpr/lpr and C57 BL/6 mice.

We have tested the hypothesis that some phenotypic characteristics of the lymphocytes from mice with lymphoproliferative disease (lpr) could be explained by abnormal glycosylation of membrane proteins. Lymph node cells from normal C57 BL/6 and from C57 BL/lpr mice were labelled with tritiated sugars. Membrane proteins were released with trypsin, then with pronase. After complete pronase digestion, glycopeptides were first separated on Bio Gel P-6 and then on Con A-Sepharose. Fractions not binding to Con A (Con A negative) were also separated on Lens culinaris agglutinin-Sepharose. Marked differences between normal and lpr cells were noticed. First, there were more glucosamine-labelled peptides with very high molecular weight (eluting fast on Bio Gel P-6) on lpr cells than on normal lymphocytes. Second, the proportion of mannose-labelled peptides binding to Con A was smaller in the lpr cells. Third, among the Con A negative peptides, the proportion binding to Lens culinaris agglutinin was higher in lpr cells. Thus, lpr cells seem to carry more alpha 1-6 fucosylated chains and larger size carbohydrates. These alterations were also confirmed by gel electrophoresis of lectin-selected iodinated cell surface antigens and seem to be restricted to a very limited number of peptides. Thus, there may be primary changes in glycosylation in lpr cells. Alternatively, the glycosylation pattern of lpr cells may be characteristic for a subpopulation of T-lymphocytes that is expanded in this disease, or for a certain stage of activation. A large proportion of Con A-negative, Lens culinaris-positive peptides is a rather unusual feature in murine cells and requires further investigation.     

Age-related immunohistochemical studies of A and D cells in pancreatic islets of C57BL/6J mice

Sections of pancreatic islets from C57BL/6J mice aged 3, 14, and 24 months, consisting of islets derived from the dorsal primordium (DPI) and from the ventral primordium (VPI), were immunostained using the peroxidase-antiperoxidase (PAP) procedure for localization of glucagon (A cells) and somatostatin (D cells). The density (A or D cell area/islet area) of immunopositive cells were determined using computer-assisted image analysis. The density of A cells was significantly less in VPI of 14- and 24-month-old mice compared to 3-month-old mice. The density of A cells in 24 month DPI was less than 3 month DPI but no different from 14 month DPI. The mean area (microns 2) of A cells (only in DPI) was significantly less at 24 months compared to the 3 and 14 month groups. There were no differences in somatostatin staining when comparing the three age groups, although at all ages the density of D cells was always greater in the DPI. In conclusion, the major difference between the young and older mice was a deficiency of glucagon-stained cells in older mice. These results might be important in explaining improved glucose tolerance in aged C57BL/6J mice.     

Revascularization and remodelling of pancreatic islets grafted under the kidney capsule

The revascularization and the structural changes resulting from interactions between the graft and the host were investigated in transplanted pancreatic islets under the kidney capsule. Islets were isolated from mice pancreata and transplanted in syngeneic diabetic animals. Graft-bearing kidneys were collected on different days post-transplant and processed for light microscopy, immunohistochemistry and transmission electron microscopy. A numerical analysis was performed in order to compare the percentage number of the different types of cells in native islets and at different time points after the transplant. Recipient animals reversed diabetes within 4 days. An intraperitoneal glucose tolerance test was performed to determine islet functionality under stressful conditions. During the initial few days post-transplant, the islets showed peculiar shapes and the graft tended to aggregate along the vessels. Starting at days 4-7 post-transplant, islets were revascularized from vessels connected to both the cortical and the capsular vascular network of the kidney. From day 7-14 post-transplant, the vessels progressively appeared more similar in features and size to those of in situ pancreatic islets. Both the percentage number of the different cell types and the distribution of Alpha, Beta and Delta cells inside the graft were significantly different as compared with intact islets, demonstrating quantitative and structural changes after the engraftment. No concomitant proliferation of Beta cells was detected using a bromodeoxyuridin staining method. Despite the fact that quick revascularization preserved a large mass of tissue, the remodelling process of the graft and the newly formed vascularization led to a different organization of the endocrine tissue as compared with intact in situ islets. This constitutes the morphological basis for alterations of the normal intercellular interactions and may explain the altered secretory cell function often observed in transplant.     

The C57BL/6 nu/nu lpr/lpr mouse. I. Expression of the 'lpr phenotype' in the C57BL/6 genetic background

The C57BL/6 lpr/lpr mice develop within 3-6 moths a series of abnormalities of their immune system which characterize the 'lpr phenotype' and allow them to be distinguished easily from normal C57BL/6 as well as from C57BL/6 nu/nu: lymphadenopathy, hyperimmunoglobulinemia, high anti-nuclear antibody titers and, less regularly, anti-whole DNA antibody. Though C57BL/6 nu/nu occasionally present auto-antibody too, the combined use of three or four of the aforementioned parameters for each tested animal allows an easy detection of animals presenting the lpr phenotype. In our C57BL/6 lpr/lpr colony, the lymphadenopathy does not seem to start by chance in any lymphoid organ but shows a very strong preferential occurrence in the cervical lymph nodes. These parameters of the lpr phenotype have been used to trace the lpr genes and to construct the C57BL/6 nu/nu lpr/lpr as described in the companion paper.     

Surface modification of pancreatic islets using heparin-DOPA conjugate and anti-CD154 mAb for the prolonged survival of intrahepatic transplanted islets in a xenograft model

This study proposes a combination method of using 3,4-dihydorxy-l-phenylalanine (DOPA) conjugated heparin (heparin-DOPA) and a low dose of anti-CD154 monoclonal antibody (MR-1) treatment to improve the survival time of intrahepatic islet xenograft. To inhibit instant blood mediated inflammatory reactions, heparin-DOPA was directly grafted to the pancreatic islet surface. The surface coverage of heparin-DOPA, the viability and functionality of heparin-DOPA grafted islets were evaluated. In addition, the combined effect of grafted heparin-DOPA and a low dose of MR-1 (a T-cell targeting immunosuppressive drug) on the survival of islet was evaluated in a xenograft model. Both unmodified islets and heparin-DOPA grafted islets were completely rejected within 2 weeks after intraportal transplantation. However, when 0.1 mg/mouse of MR-1 was administered (at day 0, 2, 4, 6 of transplantation) to 11 mice that had heparin-DOPA grafted islets transplanted to, seven out of the recipients maintained normoglycemia over 60 days. Therefore, we propose that a developed combinatory immunoprotection protocol of surface modification of pancreatic islets using heparin-DOPA with a low dose of MR-1 can be effective in prolonging the survival rate of transplanted islets in a xenograft model.     

Nyctohemeral differences in response to restraint stress in CD-1 and C57BL/6 mice

Restraint represents psychological and physical stress. Methods used to model restraint stress in mice vary in duration, time of day during which restraint is applied, and the strain of mouse tested. The goals of this study were: (1) to identify the optimal daily time periods during which the stress response is maximized, and (2) to describe mouse strain differences, if any, in response to restraint. Groups of outbred CD-1 and inbred C57BL/6 mice were restrained for 3 h during three time points of the daily light-dark cycle: (1) the late light phase, (2) the transition between the light phase and the dark phase, and (3) the mid-dark phase. Additional mice served as control groups for food deprivation or were unhandled except for blood sampling. Mice of both strains lost significant body mass after 3 days of restraint. Unrestrained food-deprived mice lost body mass, particularly if food-deprived during transition periods. Corticosterone was elevated in restrained mice compared with control mice. Neither basal nor postrestraint corticosterone differed between strains. Corticosterone was elevated by food deprivation during transitional periods in CD-1 mice and during both transition and dark phases in C57 mice. Corticosterone response in restrained CD-1 mice was increased during the dark phase. These results suggest that the physiological response to restraint is similar in both strains. However, corticosterone responses to both restraint and food deprivation were highest during the transitional and dark phases.     

A private strain-specific idiotype-like structure discovered on CBA-anti-C57BL/6 T lymphocytes

Using rabbit anti-CBA-anti-C57BL/6 sera, a private strain-specific idiotype-like determinant(s) was detected by cellular radioimmunoassay on activated CBA—anti-C57BL/6 T cells. This structure was not expressed on other activated T lymphocytes: CBA—anti-BALB/c; C3H—anti-C57BL/6; AKR—anti-C57BL/6; A/Sn—anti-C57BL/6; BALB/c-anti-C57BL/6; DBA/2-anti-C57BL/6. It is suggested that the gene(s) coding for the private strain-specific idiotype-like determinant(s) of T-cell antigen-recognizing receptors is not located within the murine H-2 complex.     

非酒精性脂肪肝C57BL/6小鼠模型的建立

 BACKGROUND: The establishment of a safe, reliable and easily repeatable mouse model of nonalcoholic fatty liver disease is the prerequisite for the study of the diagnosis and treatment of the disease.     

Anxiety-like behavior and proinflammatory cytokine levels in the brain of C57BL/6 mice infected with Plasmodium berghei (strain ANKA)

Cerebral malaria (CM) is a severe complication resulting from Plasmodium falciparum infection. The underlying mechanisms of CM pathogenesis remain incompletely understood. The imbalance between the release of proinflammatory and anti-inflammatory cytokines has been associated with central nervous system dysfunction found in human and experimental CM. The current study investigated anxiety-like behavior, histopathological changes and release of brain cytokines in C57BL/6 mice infected with Plasmodium berghei strain ANKA (PbA). Anxiety-like behavior was assessed in control and PbA-infected mice using the elevated plus maze test. Histopathological changes in brain tissue were assessed by haematoxylin and eosin staining. Brain concentration of the cytokines IL-1β, IL-4, IL-10, TNF-α and IFN-γ was determined by ELISA. We found that PbA-infected mice on day 5 post-infection presented anxiety symptoms, histopathological alterations in the brainstem, cerebrum and hippocampus and increased cerebral levels of proinflammatory cytokines IL-1β and TNF-α. These findings suggest an involvement of central nervous system inflammatory mediators in anxiety symptoms found in CM.     

Afferent connections of the parabrachial nucleus in C57BL/6J mice

Although the mouse is an experimental model with an increasing importance in various fields of neuroscience, the characteristics of its central gustatory pathways have not yet been well documented. Recent electrophysiological studies using the rat and hamster have revealed that taste processing in the brainstem gustatory relays is under the strong influence of inputs from forebrain gustatory structures. In the present study, we investigated the organization of afferent projections to the mouse parabrachial nucleus (PbN), which is located at a key site between the brainstem and gustatory, viscerosensory and autonomic centers in the forebrain. We made injections of the retrograde tracer fluorogold centered around the “waist” area of the PbN, whose neurons are known to be highly responsive to taste stimuli. Retrogradely labeled neurons were found in the infralimbic, dysgranular and agranular insular cortex as well as the claustrum; the bed nucleus of the stria terminalis and the substantia innominata; the central nucleus of the amygdala; the lateral and medial preoptic areas, the paraventricular, the dorsomedial, the ventromedial, the arcuate, and the lateral hypothalamic areas; the periaqueductal gray, the substantia nigra pars compacta, and the ventral tegmental area; the supratrigeminal nucleus, rostral and caudal nucleus of the solitary tract; the parvicellular intermediate and gigantocellular reticular nucleus; the caudal and interpolar divisions of the spinal trigeminal nucleus, dorsomedial spinal trigeminal nucleus, and the area postrema. Numbers of labeled neurons in the main components of the gustatory system including the insular cortex, bed nucleus of the stria terminalis, central nucleus of the amygdala, lateral hypothalamus, and rostral nucleus of the solitary tract were quantified. These results are basically consistent with those of the previous rat and hamster studies, but some species differences were found. Functional implications of these afferent inputs are discussed with an emphasis on their role in taste.     

Abnormality in the cerebellar folial pattern of C57BL/6J mice

The characteristic folial pattern of the mouse cerebellum is formed during postnatal development. We observed this process in C57BL/6J (B6) mice in detail, and found an abnormal folial pattern in a specific region (lobules VIII and IX of the vermis) in a substantial number of B6 mice. The frequency of this abnormality increased during postnatal development and reached 55% in the adult. Thus, the present study showed an abnormality in the cerebellar folial pattern of B6 mice, a mouse widely used in knockout studies, and called for caution in the phenotypic analysis of knockout mice of the B6 genetic background.     

小鼠恶性黑色素移植瘤模型的建立及其淋巴管内皮细胞透明质酸受体1的表达

目的:建立小鼠皮肤恶性黑色素移植瘤模型,探讨小鼠皮肤恶性黑色素移植瘤组织内淋巴管的生成情况。方法:体外培养B16瘤细胞,接种B16瘤细胞于C57BL/6小鼠右侧背部皮内,构建C57BL/6小鼠皮肤恶性黑色素移植瘤模型;应用H-E染色、淋巴管内皮细胞透明质酸受体1(1ymphatic vessel endothelial hyaluronan receptor-1, LYVE-1)免疫组化染色确认模型和观察肿瘤组织内淋巴管的生成情况。结果:建立了恶性黑色素移植瘤模型;LY- VE-1主要着色于正常组织和移植瘤组织中淋巴管内皮细胞的细胞膜上;恶性黑色素瘤组织中淋巴管密度明显高于正常皮肤组织。结论:构建C57BL/6小鼠皮肤恶性黑色素移植瘤模型是获得恶性黑色素瘤组织和进一步研究的有效手段;LYVE-1是特异性较高的淋巴管内皮标记物;小鼠皮肤恶性黑色素移植瘤组织中可能存在淋巴管的新生。     

Suppression of interferon synthesis during the graft versus host reaction in (CBA×C57BL/6) F1 mice

During the development of the graft versus host reaction (GVHR) in (CBA×C57BL/6) F₁ mice after transplantation of spleen cells from mice of the parental C57BL/6 strain, production of serum interferon induced by intraperitoneal injection of Newcastle disease virus was sharply reduced. Interferon production was reduced and later completely abolished in cultures of bone marrow cells from mice during development of the GVHR. This phenomenon can serve as a criterion of the development of the GVHR.Department of Virology, N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. Department of Microbiology, Smolensk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. D. Solov'ev.) Translated from Byulletin' Éksperimental'noi Biologii i Meditsiny, Vol. 82, No. 9, pp. 1098–1100, September, 1976.     

A multimodal, multidimensional atlas of the C57BL/6J mouse brain

Strains of mice, through breeding or the disruption of normal genetic pathways, are widely used to model human diseases. Atlases are an invaluable aid in understanding the impact of such manipulations by providing a standard for comparison. We have developed a digital atlas of the adult C57BL/6J mouse brain as a comprehensive framework for storing and accessing the myriad types of information about the mouse brain. Our implementation was constructed using several different imaging techniques: magnetic resonance microscopy, blockface imaging, classical histology and immunohistochemistry. Along with raw and annotated images, it contains database management systems and a set of tools for comparing information from different techniques. The framework allows facile correlation of results from different animals, investigators or laboratories by establishing a canonical representation of the mouse brain and providing the tools for the insertion of independent data into the same space as the atlas. This tool will aid in managing the increasingly complex and voluminous amounts of information about the mammalian brain. It provides a framework that encompasses genetic information in the context of anatomical imaging and holds tremendous promise for producing new insights into the relationship between genotype and phenotype. We describe a suite of tools that enables the independent entry of other types of data, facile retrieval of information and straightforward display of images. Thus, the atlas becomes a framework for managing complex genetic and epigenetic information about the mouse brain. The atlas and associated tools may be accessed at http://www.loni.ucla.edu/MAP.     

Age-correlated changes in dopaminergic nigrostriatal perikarya of the C57BL/6NNia mouse

Alterations in neurotransmitter systems of the basal ganglia have been postulated to contribute to the disruption of motor function and balance associated with aging. This study examined nigrostriatal (A9) and mesolimbic (A10) dopamine neurons for qualitative age-correlated changes using fluorescence histochemistry for catecholamines and immunocytochemical techniques for the catecholamine-synthesizing enzyme, tyrosine hydroxylase. Results from this study suggest that age-correlated morphological changes in A9 but not all A10 neurons in the midbrain are present in mature adult (10-month) C57BL/6NNia mice and show a progressive increase in severity until at least 30 months of age. These changes are characterized by a progressive accumulation of lipofuscin in dopamine-containing perikarya, a markedly reduced dopamine content per cell as determined visually by histofluorescence, and an increase in the number of large, fluorescent axonal dilations in dopamine-containing fibers of the mesolimbic and nigrostriatal systems. These data suggest that heterogeneous morphological aging patterns exist within dopamine-containing neurons of the midbrain and that based upon their terminal projection sites, various regions of the striatum and cortex may be differentially affected in the aged brain. In addition, these findings support the belief that age-related changes in neural structure are not generalized to an entire brain nucleus or cell type but are selective for individual cells within an affected area.