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Purpose Suicidality can be a serious feature of psychiatric symptoms in encephalitis. Investigating the psychiatric behavior associated with suicidality in animal models of encephalitis is important; thus, determining whether normal laboratory animals are aware of death is necessary. Methods To examine the behavioral and brain activity changes associated with death of conspecifics, laboratory mice were exposed to a cadaveric mouse or an anesthetized mouse. Behavioral tasks associated with anxiety and locomotion were conducted after repeated exposure. Neural activity in the medial prefrontal cortex during the cadaver exploration was investigated using electroencephalographic recordings. Results During repeated exposure, mice in the cadaver group showed a gradual decrease in time exploring the cadaver, which was not observed in mice in the anesthesia group. The cadaver group also exhibited increased levels of anxiety in the light/dark transition and elevated plus maze tasks and displayed increased locomotor activity in the open field test. In an electrophysiological study, different brain oscillations were observed when mice were exposed to a cadaveric mouse and an anesthetized mouse. Enhanced delta-band activity and reduced theta- and alpha-band activities were observed during cadaver exploration. Conclusion The present study results showed that experiences involving dead conspecifics strongly affect mouse behavior and brain activity. These findings may be helpful in treating patients with psychiatric symptoms and aid in understanding the concept of death recognition/awareness in laboratory animals.

The purpose of the research is to study the effect of extractive substances from a complex of herbs (R. Carthamoides, S. Coronate, F. ulmaria )on individual indicators of the metabolism of laboratory mice, pregnant sows and piglets obtained from them. A phytoextract containing ecdysteroids and flavonoids was orally administered to white mice ( three experimental and one control group of 15 mice) in doses of 0.1; 0.2 and 0.3 ml during 14 days that provided an increase in the average daily weight gain by 20.8-48.5% (P 0.05). It has been established that the phytoextract had an anabolic effect on white mice, did not cause a negative effect on the studied biochemical parameters of metabolism in pregnant sows, and contributed to an increase in the number of live newborns in comparison with the control.

Актуальность. Важным аспектом нарушения естественного нормального течения эмбриогенеза является влияние в пренатальный период факторов внешней и внутренней среды, которые оказывают воздействие на дифференцировку органов репродуктивной системы во взрослом организме мужского и женского пола. Цель исследования изучить и оценить результаты изменений соматометрических показателей потомства лабораторных мышей при пренатальном воздействии фулвестранта. Материалы и методы исследования. Экспериментальные исследования выполнялись на потомстве лабораторных мышах, матерям которых в отдельности на 11 сутки беременности пренатального периода в одно и то же вечернее время суток вводили исследуемый препарат. Полученное потомство лабораторных мышей были разделены на 5 групп. Интактная группа без воздействия. Контрольной группе вводили касторовое масло в дозе 0,8 мкг/кг (n=5; «МК»), первой экспериментальной группе вводили однократно, внутримышечно фулвестрант в виде 0,08 мл 0,0005% в дозе 20 мкг/кг (n=5; «Ф-20»), второй экспериментальной группе вводили однократно, внутримышечно фулвестрант 0,4 мл 0,0005% в дозе 100 мкг/кг (n=5; «Ф-100»), третьей экспериментальной группе вводили однократно, внутримышечно фулвестрант 0,8 мл 0,0005% в дозе 200 мкг/кг (n=5; «Ф-200»). У полученного потомства проводились соматометрические исследования. Результаты и их обсуждение. При однократном внутримышечном пренатальном воздействии препарата фулвестранта в потомстве мужского пола наблюдается усиление маскулинизирующего эффекта, в результате чего блокируются эстрогеновые рецепторы и работают только андрогеновые, тогда как в потомстве женского пола проявляется феминизирующий отсроченный эффект. Изучение дозозависимых эффектов пренатального введения эстрогенов продемонстрировало как стимулирующее, так и ингибирующее воздействие гормонов на соматометрические показатели потомства. Заключение. В результате пренатального воздействия эстрогенов в раннем постнатальном онтогенезе наблюдались изменения соматометрических показателей, обусловленные воздействием различных доз эстрогенов. Лимитирование дозозависимого действия эстрогенных препаратов во время беременности позволит избежать неблагоприятных эффектов в постнатальном онтогенезе., Relevance. An important aspect of the violation of the natural normal course of embryogenesis is the influence of external and internal environmental factors in the prenatal period, which affect the differentiation of the organs of the reproductive system in the adult male and female body. The research purpose was to study and to evaluate the results of changes in somatometric parameters of the offspring of laboratory mice under prenatal exposure to fulvestrant. Materials and methods of research. Experimental studies were performed on the offspring of laboratory mice, whose mothers were separately injected with the test drug on the 11th day of pregnancy of the prenatal period at the same evening time of the day. The resulting offspring of laboratory mice were divided into 5 groups. Intact group was without exposure. The control group was administered castor oil at a dose of 0.8 mcg / kg (n= 5; "MK"), the first experimental group was administered once, intramuscularly fulvestrant in the form of 0.08 ml 0.0005% at a dose of 20 mcg / kg (n=5; "F -20. The second experimental group was administered once, intramuscularly fulvestrant 0.4 ml 0.0005% at a dose of 100 mcg / kg (n=5; "F-100"), the third experimental group was administered once, intramuscularly fulvestrant 0.8 ml 0.0005% at a dose of 200 mcg / kg (n=5; "F-200"). Somatometric studies were carried out in the resulting offspring. Results and its discussion. With a single intramuscular prenatal exposure to fulvestrant in male offspring, an increase in the masculinizing effect is observed, as a result of which estrogen receptors are blocked and only androgen ones work, whereas in female offspring a feminizing delayed effect is manifested. The study of dose-dependent effects of prenatal administration of estrogens demonstrated both stimulating and inhibitory effects of hormones on the somatometric parameters of offspring. Conclusion. As a result of prenatal exposure to estrogens in early postnatal ontogenesis, changes in somatometric parameters were observed due to exposure to various doses of estrogens. Limiting the dose-dependent effect of estrogenic drugs during pregnancy will help to avoid adverse effects in postnatal ontogenesis.

Актуальность. Для регуляции овариально-менструального цикла, зачатия, поддержания, разрешения и предупреждения беременности применяют эстрогены. В связи со значительными успехами молекулярной биологии у морфологов появилась возможность иммуноцитохимически маркировать клетки при различных фазах клеточного цикла. Большое внимание уделяется изучению молекулярно-биологическому маркеру, характеризующий пролиферацию белок Ki-67, который является наиболее информационным, адекватным, удобным в использовании. Цель исследования изучение прогностического значения маркера Ki-67 при пренатальном воздействии различных доз синтетического аналога эстрогена синэстрола на яичники потомства лабораторных мышей. Материалы и методы исследования. Эксперимент выполнен на потомстве лабораторных мышей, матерям которых на стадии гестации £11.5 внутримышечно однократно вводили экспериментальные дозы синтетического аналога эстрогена синэстрола. Иммуногистохимический анализ проводили на срезах с парафиновых блоков яичников потомства, предназначенных для стандартного морфологического исследования. Оценку окрашенных препаратов проводили с использованием светового микроскопа Leica. В 10 полях зрения каждого образца при увеличении х400 производили подсчет иммунопозитивных клеток с положительной реакцией по коричневому окрашиванию ядра. Среднее число Ki-67 иммунопозитивных клеток вычисляли соотношением позитивно окрашенных клеток к негативно окрашенным клеткам (на 100 просчитанных клеток). Экспрессию маркера определяли в следующих показателях яичников потомства: в первичных, вторичных, третичных фолликулах; в желтом теле; в строме органа. Результаты и их обсуждение. В первой экспериментальной группе «С-25» во всех исследуемых показателях наблюдалось снижение митотической активности клеток при экспрессии маркера Ki-67, свидетельствующее об ускоренной физиологической гибели клеток. Во второй экспериментальной группе «С-40» уровень экспрессии белка Ki-67 в желтых телах достоверно уменьшился, но вместе с тем увеличение экспрессии произошли в остальных показателях, демонстрирующие о снижении процесса естественной гибели клеток. В третьей экспериментальной группе «С-50» наблюдался однонаправленный процесс роста количества иммунопозитивно-окрашенных клеток во всех исследуемых показателях, свидетельствующие о снижении процесса естественной гибели клеток. Заключение. Веденные исследуемые дозы синтетического эстрогена синестрола в пренатальный период вызывают морфофункциональные нарушения в яичниках потомства. Дозазависимость эстрогенов может служить фоном для развития структурных изменений в яичниках потомства, о чем свидетельствует экспрессия маркера Ki-67., Relevance. Estrogens are used to regulate the ovarian-menstrual cycle, conception, maintenance, resolution and prevention of pregnancy. Due to significant advances in molecular biology, morphologists have the opportunity to immunocytochemically label cells at various phases of the cell cycle. Much attention is paid to the study of the molecular biological marker that characterizes proliferation the protein Ki-67, which is the most informative, adequate, and convenient to use. The research purpose was to study the prognostic value of the Ki-67 marker during prenatal exposure of various doses of synthetic estrogen analog synestrol to the ovaries of offspring of laboratory mice. Materials and methods. The experiment was performed on the offspring of laboratory mice, whose mothers at the stage of gestation E11.5 were intramuscularly administered experimental doses of the synthetic analogue of estrogen synestrol once. Immunohistochemical analysis was performed on sections from paraffin blocks of ovaries of offspring intended for standard morphological examination. The stained preparations were evaluated using a Leica light microscope. In 10 fields of view of each sample, at an increase of x400, immune-positive cells with a positive reaction to the brown staining of the nucleus were counted. The average number of Ki-67 immunopositive cells was calculated by the ratio of positively colored cells to negatively colored cells (per 100 calculated cells). The expression of the marker was determined in the following indicators of the ovaries of the offspring: in primary, secondary, tertiary follicles; in the corpus luteum; in the stroma of the organ. Results and its discussion. In the first experimental group "C-25", a decrease in mitotic activity of cells was observed in all the studied parameters with the expression of the Ki-67 marker, indicating accelerated physiological cell death. In the second experimental group "C-40", the expression level of the Ki-67 protein in yellow bodies significantly decreased, but at the same time, an increase in expression occurred in the remaining indicators, demonstrating a decrease in the process of natural cell death. In the third experimental group "C-50", a unidirectional process of increasing the number of immunopositive-stained cells was observed in all the studied indicators, indicating a decrease in the process of natural cell death. Conclusion. The studied doses of synthetic estrogen synestrol in the prenatal period cause morphofunctional disorders in the ovaries of offspring. The dose dependence of estrogens can serve as a background for the development of structural changes in the ovaries of offspring, as evidenced by the expression of the Ki-67 marker.

Laboratory mice are predominantly used for one experiment only, i.e., new mice are ordered or bred for every new experiment. Moreover, most experiments use relatively young mice in the range of late adolescence to early adulthood. As a consequence, little is known about the day-to-day life of adult and aged laboratory mice. Here we present a long-term data set with three consecutive phases conducted with the same male mice over their lifetime in order to shed light on possible long-term effects of repeated cognitive stimulation. One third of the animals was trained by a variety of learning tasks conducted up to an age of 606 days. The mice were housed in four cages with 12 animals per cage; only four mice per cage had to repeatedly solve cognitive tasks for getting access to water using the IntelliCage system. In addition, these learner mice were tested in standard cognitive tests outside their home-cage. The other eight mice served as two control groups living in the same environment but without having to solve tasks for getting access to water. One control group was additionally placed on the test set-ups without having to learn the tasks. Next to the cognitive tasks, we took physiological measures (body mass, resting metabolic rate) and tested for dominance behavior, and attractivity in a female choice experiment. Overall, the mice were under surveillance until they died a natural death, providing a unique data set over the course of virtually their entire lives. Our data showed treatment differences during the first phase of our lifetime data set. Young learner mice showed a higher activity, less growth and resting metabolic rate, and were less attractive for female mice. These effects, however, were not preserved over the long-term. We also did not find differences in dominance or effects on longevity. However, we generated a unique and valuable set of long-term behavioral and physiological data from a single group of male mice and note that our long-term data contribute to a better understanding of the behavioral and physiological processes in male C57Bl/6J mice.

A comparison of whole-fish polychlorinated biphenyl (PCB) and total mercury (Hg) concentrations in mature males with those in mature females may provide insights into sex differences in behavior, metabolism, and other physiological processes. In eight species of fish, we observed that males exceeded females in whole-fish PCB concentration by 17 to 43 %. Based on results from hypothesis testing, we concluded that these sex differences were most likely primarily driven by a higher rate of energy expenditure, stemming from higher resting metabolic rate (or standard metabolic rate (SMR)) and higher swimming activity, in males compared with females. A higher rate of energy expenditure led to a higher rate of food consumption, which, in turn, resulted in a higher rate of PCB accumulation. For two fish species, the growth dilution effect also made a substantial contribution to the sex difference in PCB concentrations, although the higher energy expenditure rate for males was still the primary driver. Hg concentration data were available for five of the eight species. For four of these five species, the ratio of PCB concentration in males to PCB concentration in females was substantially greater than the ratio of Hg concentration in males to Hg concentration in females. In sea lamprey (Petromyzon marinus), a very primitive fish, the two ratios were nearly identical. The most plausible explanation for this pattern was that certain androgens, such as testosterone and 11-ketotestosterone, enhanced Hg-elimination rate in males. In contrast, long-term elimination of PCBs is negligible for both sexes. According to this explanation, males not only ingest Hg at a higher rate than females but also eliminate Hg at a higher rate than females, in fish species other than sea lamprey. Male sea lamprey do not possess either of the above-specified androgens. These apparent sex differences in SMRs, activities, and Hg-elimination rates in teleost fishes may also apply, to some degree, to higher vertebrates including humans. Our synthesis findings will be useful in (1) developing sex-specific bioenergetics models for fish, (2) developing sex-specific risk assessment models for exposure of humans and wildlife to contaminants, and (3) refining Hg mass balance models for fish and higher vertebrates.

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies, 11, 14, 11A14U: 1-9

Search of new approaches for harmless, non-medication treatment of body dysfunctions is still on the agenda of vet and human practitioners and researchers as well. This study presents evaluation of the effect of “Stress Relief” dietary supplement (SR) on mice behaviour under different acute short-term stress conditions and treatment duration. Five experiments were performed and in each 40 animals were randomly split into four (I–IV) groups, where I and II — non-stressed mice, III and IV — stressed animals, I and III received water with trace mineral solution (TMS), II and IV received water with SR. As stress factors, forced swimming, rodent predator odour or both together were applied. Locomotor activity under normal and stress conditions in Open Field were observed and measured by a SMART video-tracking system. Blood glucose level was measured as well. SR showed a reversal of stress-decreased locomotor activity in all stress models — distance walked increased almost twice (p < 0.0001), central zone crossings and time spent in it were 2–4 times greater than in the control group (p < 0.0001 and p = 0.0002, respectively), and fast movement episodes and maximal speed increased by 50–200%. In addition, complete normalisation of stress-induced elevation of blood glucose level (p < 0.0001) was noted. These results demonstrate for the first time that the effect of “Stress Relief” formula (water additives–minerals processed by know-how way in Vital Force Technology using Dr. Yury Kronn method) can be observed in laboratory animals, and that the effects are significant and repeatable. SR shows fear- and stress-reducing activity, which does not sufficiently differ between 7-, 9-, 14-, 28- and 32-day treatment regimes.

Aim. Experimental evaluation of effect of E. coli LPS fractions on phagocyte and metabolic activity of blood neutrophils of laboratory mice with induced immune deficiency. Materials and methods. Phagocyte activity was evaluated by phagocyte number (PN), phagocyte index (PI) and integral phagocyte index (IPI), intensity of metabolism and energetic processes of enzyme systems - by test of tetrazolium nitro blue (TNB), mean cytochemical coefficient (MCC) in spontaneous and induced tests and stimulation index (SI). Results. LPS-3 substance administration into mice with secondary immune deficiency has resulted in a significantly highest increase of PN (15.8%), IPI (17.7%), TNB-IN (10.3%), cytochemical coefficients MCC-IN (u.) and IS (u.) - 14.8 and 10.9%, respectively, compared with the parameters of immune deficient mice that had received licopid. Conclusion. Some fractions of E. coli M17 polysaccharide have immune stimulating activity.

In recent years, the microalgae (Chlorella vulgaris) have increasingly attracted great interest as a potential source of pharmacologically active compounds. Showing anticoagulation, antioxidant and antitumor activities of Chlorella revealed its hypotensive properties. The aim of this study was to evaluate the effects of Chlorella suspension on the weight of the animals, their moving activity, and erythropoiesis. The study was performed on males and females of ICR mice. The animals from the experimental group drank only the Chlorella suspension during 3 weeks and were given standard food. Control animals drank during this period only water and had the same food. The body weight of males in the control and the experimental group with Chlorella did not change, while females in the experimental group showed an increase of body weight in a week. A similar pattern was obtained for estimation of animal body weight changes relative to food consumption. The number of red blood cells in females and males from group with Chlorella increased only after 3 weeks after the start of the experiment. Hemoglobin also increased only after 3 weeks after the start of Chlorella consumption, but only for females. All groups of animals had the same motor activity during experiment. Blood sampling resulted in a reduction of activity in control males and females as well as in males with Chlorella. The motor activity of females with Chlorella after blood sampling did not change. So, consumption of the Chlorella suspension by females leads to more effective digestion and resulted in increased body weight, improved erythropoiesis resulted in increased red blood cells and hemoglobin and also increased their resistance to acute stress. The males in the same situation increased only the erythropoiesis.

Background: The key point in the production procedure of inbred animals is checking the genetic purity. Skin grafting and coat color test are used traditionally to prove genetic purity, but they have some disadvantages. Recent advances in DNA profiling have enabled scientists to check easily the genetic purity of laboratory animals. In the current study, a set of microsatellite markers was designed to check the purity of inbred laboratory mice. Materials and Methods: Twenty microsatellites located on 20 chromosomes were employed to create a distinctive genetic profile for parentage analysis. Each individual primer was designed based on distinguishable colors and separable sizes. Results: Twenty specific microsatellite markers were used in the polymerase chain reaction mixture to identify inbred BALB/cJ strains. Our results confirmed that the designed microsatellites are excellent genetic markers for testing inbred BALB/cJ strain in laboratories. Conclusion: Our study showed that genetic profiling using microsatellite markers allows us to detect the genetic differences of laboratory mouse species in quality control tests and validation steps.

Background & objectives: For detection and molecular characterization of Babesia microti in laboratory mice from India. Methods: A total of 625 mice were screened by peripheral blood smear examination and subsequently was confirmed by PCR using a piroplasm conserved primer set (Piro A/B). Nested PCR was done using a species-specific primer targeting the gene encoding the small subunit ribosomal RNA (18S rRNA). The PCR products were cloned, purified and sequenced. A total of 12 isolates were obtained. The sequences were aligned and phylogenetic trees were prepared with other published Babesia spp. sequences. Results: B. microti was detected with a total infection rate of 8.80%. The higher rate of infection was observed by species specific PCR (8.80%) than examined by blood smear (7.20%). Sequence and phylogenetic analysis showed that Babesia species detected in mice were genetically identical to the genotypes of B. microti and can be easily distinguished from other genotypes of Babesia parasites by neighbour joining and maximum likelihood method. Intra-species analysis indicated that all the twelve isolates from six North-Eastern states of India have a close identity but inter-species showed genetic reservoir host for transmission of babesial infection to humans. Interpretation & conclusion: The detection of Babesia microti may suggest that laboratory mice may serve as potential reservoir host for human infection and possibility of innovative way of diagnosing and control of human babesiosis.

Wild animals' immune responses contribute to their evolutionary fitness. These responses are moulded by selection to be appropriate to the actual antigenic environment in which the animals live, but without imposing an excessive energetic demand which compromises other component of fitness. But, exactly what these responses are, and how they compare with those of laboratory animals, has been little studied. Here, we review the very small number of published studies of immune responses of wild rodents, finding general agreement that their humoral (antibody) responses are highly elevated when compared with those of laboratory animals, and that wild rodents' cellular immune system reveals extensive antigenic exposure. In contrast, proliferative and cytokine responses of ex vivo-stimulated immune cells of wild rodents are typically depressed compared with those of laboratory animals. Collectively, these responses are appropriate to wild animals' lives, because the elevated responses reflect the cumulative exposure to infection, while the depressed proliferative and cytokine responses are indicative of effective immune homeostasis that minimizes immunopathology. A more comprehensive understanding of the immune ecology of wild animals requires (i) understanding the antigenic load to which wild animals are exposed, and identification of any key antigens that mould the immune repertoire, (ii) identifying immunoregulatory processes of wild animals and the events that induce them, and (iii) understanding the actual resource state of wild animals, and the immunological consequences that flow from this. Together, by extending studies of wild rodents, particularly addressing these questions (while drawing on our immunological understanding of laboratory animals), we will be better able to understand how rodents' immune responses contribute to their fitness in the wild.

The poor predictive quality of currently used animal models in preclinical research is an important cause of the high attrition of promising drug candidates for human autoimmune disease in clinical trials. Examples from own work in a primate multiple sclerosis (MS) model illustrate that important lessons can be learned from a critical reassessment of failed drugs in the animal model, which can help improve the animal model and better understand the targeted disease.

To characterize temporal patterns of transcriptional activity during normal lung development, we generated genome wide gene expression data for 26 pre- and post-natal time points in three common inbred strains of laboratory mice (C57BL/6J, A/J, and C3H/HeJ). Using Principal Component Analysis and least squares regression modeling, we identified both strain-independent and strain-dependent patterns of gene expression. The 4,683 genes contributing to the strain-independent expression patterns were used to define a murine Developing Lung Characteristic Subtranscriptome (mDLCS). Regression modeling of the Principal Components supported the four canonical stages of mammalian embryonic lung development (embryonic, pseudoglandular, canalicular, saccular) defined previously by morphology and histology. For postnatal alveolar development, the regression model was consistent with four stages of alveolarization characterized by episodic transcriptional activity of genes related to pulmonary vascularization. Genes expressed in a strain-dependent manner were enriched for annotations related to neurogenesis, extracellular matrix organization, and Wnt signaling. Finally, a comparison of mouse and human transcriptomics from pre-natal stages of lung development revealed conservation of pathways associated with cell cycle, axon guidance, immune function, and metabolism as well as organism-specific expression of genes associated with extracellular matrix organization and protein modification. The mouse lung development transcriptome data generated for this study serves as a unique reference set to identify genes and pathways essential for normal mammalian lung development and for investigations into the developmental origins of respiratory disease and cancer. The gene expression data are available from the Gene Expression Omnibus (GEO) archive (GSE74243). Temporal expression patterns of mouse genes can be investigated using a study specific web resource (http://lungdevelopment.jax.org).

SUMMARYAttributes of an animal’s life history, such as reproductive rate or longevity, typically fall along a ‘slow–fast’ continuum. Animals at the fast end of this continuum, such as temperate birds, are thought to experience high rates of mortality and invest more resources in reproduction, whereas animals at the slow end, such as tropical birds, live longer, have fewer offspring and invest more resources in self-maintenance. We have previously shown that tropical birds, compared with temperate species, have a reduced basal (BMR) and peak metabolic rate (PMR), patterns consistent with a slow pace of life. Here, we elucidate a fundamental linkage between the smaller mass of central organs of tropical species and their reduced BMR, and between their smaller flight muscles and reduced PMR. Analyses of up to 408 species from the literature showed that the heart, flight muscles, liver, pancreas and kidneys were smaller in tropical species. Direct measurements on 49 species showed smaller heart, lungs, flight muscles, liver, kidneys, ovaries and testes in tropical species, as well as lower feather mass. In combination, our results indicate that the benign tropical environment imposes a relaxed selection pressure on high levels of sustained metabolic performance, permitting species to reduce the mass of organs that are energetically costly to maintain. Brain, gizzard and intestine were exceptions, even though energy turnover of brain and intestine are high. Feather mass was 37% lower in tropical species compared with similar-sized temperate birds, supporting the idea that temperate birds require more insulation for thermoregulation.

Aspiculuris tetraptera is a heteroxynematid nematoda infecting most of the laboratory animals, occasionally mice which represent the mostly used animal for biological, medical, and pharmacological studies. The present study aimed to investigate the prevalence of nematode parasites infection in the laboratory mice Mus musculus in Egypt. Morphologically, this oxyurid possessed four distinct cephalic papillae on a cephalic plate, with three small rudimental lips carrying two sessile poorly developed labial papillae and one pair of amphidial pores. Esophagus divided into cylindrical corpus and globular bulb. Distinct cervical alae interrupted at the level of esophago–intestinal junction forming an acute angle. At the caudal end, twelve caudal papillae in male worms while an ovijector apparatus opening and a vulva surrounded by protruded lips in females were observed. The general morphological criteria include this nematode with other Aspiculuris species which were compared in the present study. Molecular characterization based on 18SSU rDNA sequencing performed to confirm the taxonomic position of this species and to documents the morphological data. Sequence alignment detects a percent of identity up to 88.0% with other Heteroxynematidae species. Phylogenetic analysis showed that the present recorded is a putative sister taxon to A. tetraptera recorded in a previous study. The SSU rDNA sequence has been deposited in the GenBank under the accession no. MG019400.

This study was carried out to determine if exposure to hot environmental temperatures had a direct, detrimental effect on sperm quality. For this the effect of whole-body heat exposure on epididymal spermatozoa of laboratory mice was investigated. C57BL/6 mice (n = 7) were housed in a microclimate chamber at 37 degrees C-38 degrees C for 8 h per day for three consecutive days, while control mice (n = 7) were kept at 23 degrees C-24 degrees C. Cauda epididymal spermatozoa were obtained 16 h after the last heat treatment. The results showed that sperm numbers were similar in the two groups (P = 0.23), but after heat treatment, a significant reduction in the percentage of motile sperm was present (P0.0001). Membrane changes of the spermatozoa were investigated by staining with phycoerythrin (PE)-conjugated Annexin V, which detects exteriorization of phosphotidylserine from the inner to the outer leaflet of the sperm plasma membrane, and 7-aminoactinomycin D (7-AAD), which binds to the sperm nucleus when the plasma membrane is damaged. The percentage of spermatozoa showing positive staining with Annexin V-PE or 7-AAD or both, was significantly higher (P0.05) in heat-exposed mice compared with controls. These results show that whole-body heat exposure to 37 degrees C-38 degrees C induces membrane changes in the epididymal spermatozoa of mice, which may lead to apoptosis.

Data on the frequency, distribution and mean intensity of the helminth fauna recovered from outbred and inbred mice conventionally maintained in Brazilian animal houses, are reported. The oxyurid nematodes Syphacia obvelata and Aspiculuris tetraptera presented overall frequencies of 91.5% and 8.5%, respectively. The frequency of S. obvelata in animals of three groups out of the four investigated ranged from 9% to 74% and A. tetraptera from 17% to 83%, since animals of one of the groups were negative for helminths. Infections due to a single species were observed in 62% of the animals, compared to 16% related to associations. The frequency of single infections in each group varied from 58.6% to 100% whereas associations varied from 24.1% to 41.4%. The analysis of specific mean intensities showed that S. obvelata was represented by 13.35 to 66.58 specimens/host and A. tetraptera by 5.85 to 16.75 specimens/host.

Indirect calorimetry (InCa) can potentially be used to noninvasively assess metabolic and age-related flexibility. To assess the use of InCa for this purpose, we tested the sensitivity and response stability over time of three InCa-based treatments in old versus adult mice. Diurnal patterns of respiratory exchange ratio were followed for 24 hours under standard conditions (Treatment 1), but the results were not stable between test periods. As a challenge, fasted mice received glucose to test switch-effectiveness from fat to glucose oxidation (Treatment 2). No differences between groups were observed, although old mice showed higher adiposity and lower white adipose tissue (WAT) mitochondrial density, indicative of age-impaired metabolic health. Lastly, adaptation to a challenge of oxygen restriction (OxR, 14.5% O2) was assessed as a novel approach (Treatment 3). This treatment stably detected significant differences: old mice did not maintain reduced oxygen consumption under OxR during both test periods, whereas adult mice did. Further biochemical and gene expression analyses showed that OxR affected glucose and lactate homeostasis in liver and WAT of adult mice, supporting the observed differences in oxygen consumption. In conclusion, InCa analysis of the response to OxR in mice is a sensitive and reproducible treatment to noninvasively measure age-impaired metabolic health.

Aggression in group-housed male mice is known to be influenced by both cage size and group size. However, the interdependency of these two parameters has not been studied yet. In this study, the level of aggression in groups of three, five, or eight male BALB/c mice housed in cages with a floor size of either 80 or 125 cm(2)/animal was estimated weekly after cage cleaning for a period of 14 weeks. Furthermore, urine corticosterone levels, food and water intake, body weight, and number of wounds were measured weekly. At the end of the experiment, tyrosine hydroxylase (TH) activity, testosterone levels, and weight of spleen, thymus, testes, and seminal vesicles were determined. Results indicate a moderate increase of intermale aggression in larger cages when compared to the smaller cages. Aggression in soups of eight animals was considerably higher than in groups of three animals. The increase of agonistic behavior was observed both in dominant and subordinate animals. Physiological parameters indicate differences in stress levels between dominant and subordinate animals. It is concluded that aggressive behavior in group-housed male BALB/c mice is best prevented by housing the animals in small groups of three to five animals, while decreasing floor size per animal may be used as a temporary solution to decrease high levels of aggression in an existing social group. (C) 2001 Elsevier Science Inc. All rights reserved.

Predator cues (both mammalian odour or avian vocalizations) are known to elicit fear-associated responses in rodents, including analgesia. In previous studies it was reported that spiny mice fail to show fear responses when presented with the calls of an owl. In order to test the hypothesis that this species (living in semiarid and rocky areas) may react to stimuli coming from reptilian predators, 40 sexually mature spiny mice (20 males, 20 females) were individually exposed to a small cylinder containing either fresh sawdust or snake odour. Behavioural changes (5 min before and 15 min after odour exposure) as well as the subsequent performance in a hot-plate test (50 +/- 0.5 degrees C) were assessed. Results indicate that exposure to the odour of a sympatric terrestrial predator affected both behavioural and physiological responses of spiny mice. Upon exposure to snake odour both sexes showed significant changes in the patterns of inactivity, Sniffing, grooming, sniffing the stimulus object (SO), withdraw reaction and in the frequency of somersaults. However, males increased the frequency of rearing, sniffing the SO, decreasing grooming more than females. No analgesic effect of odour exposure emerged; however, males showed significantly shorter latencies and higher frequencies of hindpaw licking compared to females. (C) 1999 Elsevier Science B.V. All rights reserved.

Le caryotype de Rodentolepis nana obtenu a partir de souris de laboratoires a Rio de Janeiro, Bresil, est decrit. Le numero diploide des chromosomes obtenus par la division de cellules embryonnaires est 2n = 12. Les premiere et troisieme paires presentent des centromeres subterminaux; toutes les autres paires sont acrocentriques. L'espece etudiee est differente au plan de la morphologie chromosomique de la description prealable de Mutafova et Gergova (1994) en Bulgarie, suggerant une variation intraspecifique.

Membrane fatty acid (FA) composition is correlated with longevity in mammals. The “membrane pacemaker hypothesis of ageing” proposes that animals which cellular membranes contain high amounts of polyunsaturated FAs (PUFAs) have shorter life spans because their membranes are more susceptible to peroxidation and further oxidative damage. It remains to be shown, however, that long-lived phenotypes such as the Ames dwarf mouse have membranes containing fewer PUFAs and thus being less prone to peroxidation, as would be predicted from the membrane pacemaker hypothesis of ageing. Here, we show that across four different tissues, i.e., muscle, heart, liver and brain as well as in liver mitochondria, Ames dwarf mice possess membrane phospholipids containing between 30 and 60 % PUFAs (depending on the tissue), which is similar to PUFA contents of their normal-sized, short-lived siblings. However, we found that that Ames dwarf mice membrane phospholipids were significantly poorer in n-3 PUFAs. While lack of a difference in PUFA contents is contradicting the membrane pacemaker hypothesis, the lower n-3 PUFAs content in the long-lived mice provides some support for the membrane pacemaker hypothesis of ageing, as n-3 PUFAs comprise those FAs being blamed most for causing oxidative damage. By comparing tissue composition between 1-, 2- and 6-month-old mice in both phenotypes, we found that membranes differed both in quantity of PUFAs and in the prevalence of certain PUFAs. In sum, membrane composition in the Ames dwarf mouse supports the concept that tissue FA composition is related to longevity.

Line differences for open-field behavior in chickens have been observed, and it has been shown that this behavior has a genetic component. The aim of this study was to detect quantitative trait loci (QTL) involved in open-field behavior. For this purpose, open-field behavior was studied at 5 and 29 weeks of age in F(2) hens coming from an intercross between two commercial White Leghorn laying lines selected for egg production traits. Latencies, durations, and frequencies of general activity (sitting, standing, walking, and stepping), defecation, and vocalizations were recorded individually for each bird, and a factor score was calculated. All animals (F(0), F(1), and F(2)) were screened with 180 microsatellite markers. Regression interval mapping was applied using both a paternal half-sib analysis and a line-cross analysis method. For general activity at 5 weeks of age, a significant QTL was detected on GGA4 and a suggestive QTL on GGA2 under the line-cross model. For general activity at 29 weeks of age, a significant QTL was detected on GGA4 and two suggestive QTLs were detected on GGA1 and on GGA10, respectively, also using the line-cross analysis. The QTL on GGA4 at 5 weeks of age did not overlap with the QTL on GGA4 at 29 weeks of age. The current study indicated that open-field behavior in young chickens was regulated by QTL that differ from the QTL for open-field behavior in adult chickens.

Environmental enrichment may improve the quality of life of captive animals by altering the environment of animals so that they are able to perform more of the behavior that is within the range of the animal's species specific repertoire. When enrichment is introduced into an animal's environment, it is important to evaluate the effect of the enrichment program and to assess whether the animal continues to use the enrichment in the long-term. Groups of mice were housed under either standard or enriched conditions for several weeks. Nesting material which was highly preferred in previous studies was used as enrichment. During the period of differential housing several behavioral parameters (behavioral tests and handling) and physiological parameters (urine and plasma corticosterone, food and water intake, body and adrenal weight) were monitored to determine the impact of environmental enrichment. Observations were made to determine whether or not the mice continued to use the enrichment. The results indicated that throughout the study all mice used the nesting material to build nests and that mice from enriched conditions weighed more than mice housed under standard conditions, although the latter consumed more food. No major differences for behavioral and physiological parameters were found between the groups of mice housed under different conditions. Therefore it is not likely that supply of nesting material will jeopardize the outcome of experiments. (C) 1997 Elsevier Science Inc.

Virulence and persistence in the BALB/c mouse gut was tested for 32 strains of Salmonella enterica for which genome sequencing is complete or underway, including 17 serovars within subspecies I (enterica), and two representatives of each of the other five subspecies. Only serovar Paratyphi C strain BAA1715 and serovar Typhimurium strain 14028 were fully virulent in mice. Three divergent atypical Enteritidis strains were not virulent in BALB/c, but two efficiently persisted. Most of the other strains in all six subspecies persisted in the mouse intestinal tract for several weeks in multiple repeat experiments although the frequency and level of persistence varied considerably. Strains with heavily degraded genomes persisted very poorly, if at all. None of the strains tested provided immunity to Typhimurium infection. These data greatly expand on the known significant strain-to-strain variation in mouse virulence and highlight the need for comparative genomic and phenotypic studies.

We present a consolidated view of the complexity and challenges of designing studies for measurement of energy metabolism in mouse models, including a practical guide to the assessment of energy expenditure, energy intake and body composition and statistical analysis thereof. We hope this guide will facilitate comparisons across studies and minimize spurious interpretations of data. We recommend that division of energy expenditure data by either body weight or lean body weight and that presentation of group effects as histograms should be replaced by plotting individual data and analyzing both group and body-composition effects using analysis of covariance (ANCOVA). The epidemic of obesity has generated a large

Researchers from a wide variety of backgrounds and with a broad range of goals have utilized high-throughput screening technologies (i.e., microarray technologies) to identify candidate genes that may be associated with an observable characteristic or behavior (i.e., phenotype) of interest. However, the initial microarray analyses typically also yield many genes that are not related to the phenotype of interest. Therefore, additional analyses are necessary to select the most likely candidates and eventually identify one or more genes that actually underlie that phenotype. After briefly explaining how microarray data are generated, this article describes one approach to narrowing down the resulting candidate genes and a database that can help in this analysis.