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Sample records for rodent ctenomys talarum

  1. Seasonal changes in body composition of Ctenomys talarum (Rodentia: Octodontidae): an herbivore subterranean rodent.

    PubMed

    del Valle, Juana C; López Mañanes, Alejandra A; Busch, Cristina

    2006-09-01

    Ctenomys talarum is a subterranean herbivorous rodent whose burrow systems exhibit particular characteristics, distinct from other subterranean environments. We studied seasonal variation in body composition of C. talarum in relation to energetic requirements. Body lipid content seasonally changed in C. talarum, related to reproductive cycle and thermorregulatory mechanisms. A decrease in protein body content was found only in spring. Ash content of females was lowest when most of them are in post partum estro. Observed variations in water body content could be associated with plant water content and/or metabolic regulation. Our results show the occurrence of seasonal variations in body composition in C. talarum, which could be related to the high cost of reproduction and the subterranean life style of this species.

  2. Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum.

    PubMed

    Vega-Zuniga, T; Medina, F S; Marín, G; Letelier, J C; Palacios, A G; Němec, P; Schleich, C E; Mpodozis, J

    2017-02-02

    To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well as the whole set of contralateral visual projections, appear well-developed. We conclude that these subterranean rodents exhibit, paradoxically, diurnal instead of nocturnal visual specializations, but at the same time suffer a specific regression of the anatomical substrate for stereopsis. We discuss these findings in light of the visual ecology of subterranean lifestyles.

  3. Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum

    PubMed Central

    Vega-Zuniga, T.; Medina, F. S.; Marín, G.; Letelier, J. C.; Palacios, A. G.; Němec, P.; Schleich, C. E.; Mpodozis, J.

    2017-01-01

    To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well as the whole set of contralateral visual projections, appear well-developed. We conclude that these subterranean rodents exhibit, paradoxically, diurnal instead of nocturnal visual specializations, but at the same time suffer a specific regression of the anatomical substrate for stereopsis. We discuss these findings in light of the visual ecology of subterranean lifestyles. PMID:28150809

  4. Parasite infection negatively affects PHA-triggered inflammation in the subterranean rodent Ctenomys talarum.

    PubMed

    Merlo, Julieta L; Cutrera, Ana P; Zenuto, Roxana R

    2016-02-01

    Magnitude and effectiveness of immune responses vary greatly between and within species. Among factors reported to determine this variation, parasitism is a critical one, although controversial effects of parasites over immunological indices have been reported. Information regarding immune strategies in species with different life histories is crucial to better understand the role of immune defenses in an ecological and evolutionary context. Here, we examine the influence of the parasite community on immune responsiveness of a solitary subterranean rodent, Ctenomys talarum. To do this, we assessed the impact of the natural parasite community and the experimental infection with Eimeria sp. on the phytohemagglutinin (PHA)-response, as well as other immune, condition, nutrition, and stress parameters. PHA-triggered inflammation was similarly impaired by Eimeria sp. infection alone or co-occurring with a number of gastrointestinal nematodes. None of the other physiological parameters studied were affected by parasitism. This indicates that parasitism is a general key factor modulating immune responsiveness of the host, and in particular for C. talarum, it could explain the great inter-individual variation previously observed in the PHA-response. Thus, our results highlight the importance of taking the parasite community into account in ecoimmunological studies, particularly when using immunological indices.

  5. Effect of ambient temperature on evaporative water loss in the subterranean rodent Ctenomys talarum.

    PubMed

    Baldo, María Belén; Antenucci, C Daniel; Luna, Facundo

    2015-10-01

    Subterranean rodents face unique thermoregulatory challenges. Evaporative water loss (EWL) is a crucial mechanism for maintaining heat balance in endotherms subjected to heat stress but also leads to potential dehydration. EWL depends on gradients of temperature and humidity between the surface of the individual and the surrounding environment. Underground burrows generally provide a stable water vapor saturated atmosphere which may impede evaporative heat loss (EHL). This will mainly occur when ambient temperature exceeds the upper limit of individual's thermoneutral zone, or when body temperature rises as result of digging activities. Here we evaluate the effect of ambient temperature on EWL and energy metabolism in the subterranean rodent Ctenomys talarum (tuco-tucos), which inhabits sealed burrows, but makes an extensive use of the aboveground environment. We observed that EWL is increased when ambient temperature rises above thermoneutrality; below this point, evaporation remains stable. Though EWL contributes to total heat loss by increasing ∼1.3 times at 35°C, dry thermal conductance is raised four times. In tuco-tucos' burrows both non-evaporative and, to some extent, evaporative and behavioral mechanisms are essential for body temperature regulation, preventing overheating at high ambient temperatures in a water vapor-saturated atmosphere.

  6. Immune challenge but not dietary restriction affects spatial learning in the wild subterranean rodent Ctenomys talarum.

    PubMed

    Schleich, Cristian E; Zenuto, Roxana R; Cutrera, Ana P

    2015-02-01

    Several lines of evidence suggest that learning and triggering an immune response are both metabolically expensive and thus likely to be subject to nutritional trade-offs between them and other competing demands. Therefore, we evaluated if an immune challenge with a novel antigen affects spatial learning in the subterranean rodent Ctenomys talarum under two different dietary conditions. The results showed that immune-challenged animals were affected in their spatial learning capabilities, increasing the number of errors and marginally the time required to reach the goal of a complex labyrinth. No effect of the dietary restriction nor interaction between factors were observed. This work provides support for the existence of a trade-off between the costs of the immune defense and learning abilities, indicating that when investment is required to fight infection, fewer resources are available for learning. The absence of effect of nutritional condition on this trade-off suggests that other physiological processes, besides cognition, may be limited by the energetic resources necessary to the more immediately critical immune response.

  7. Differential responses of cortisol and corticosterone to adrenocorticotropic hormone (ACTH) in a subterranean rodent (Ctenomys talarum).

    PubMed

    Vera, Federico; Zenuto, Roxana Rita; Antenucci, Carlos Daniel

    2012-03-01

    We aimed to evaluate the responses of cortisol, corticosterone, and blood glucose to adrenocorticotropic hormone (ACTH) in males and females of the subterranean rodent Ctenomys talarum and addressed interannual variations in the plasma levels of both hormones. The most important results indicate that: (1) cortisol positively responds to the ACTH signal but corticosterone does not, even though corticosterone levels were higher than cortisol concentrations, (2) plasma corticosterone concentrations in free-living animals were 20 times higher compared to values reported for the same population during previous annual periods and, as cortisol levels were similar, this resulted in much lower cortisol/corticosterone ratios, (3) cortisol and corticosterone differentiated in their relative proportions in plasma in free-living males and females. These results indicate that cortisol and corticosterone are differentially regulated in our study species and emphasize that a remarkable temporal variation in the relative proportions of these hormones may occur in natural populations. Therefore, the conclusions regarding the presence of cortisol and corticosterone in plasma of wild animals may differ substantially depending on the moment when the study is conducted. Recent data indicate that cortisol and corticosterone are not interchangeable hormones in species of free-living vertebrates. We suggest that, in addition to the classical roles of glucocorticoids (GCs), it is crucial that other physiological functions be kept in mind when interpreting GC data from wild species.

  8. Postnatal ontogeny of limb proportions and functional indices in the subterranean rodent Ctenomys talarum (Rodentia: Ctenomyidae).

    PubMed

    Echeverría, Alejandra Isabel; Becerra, Federico; Vassallo, Aldo Iván

    2014-08-01

    Burrow construction in the subterranean Ctenomys talarum (Rodentia: Ctenomyidae) primarily occurs by scratch-digging. In this study, we compared the limbs of an ontogenetic series of C. talarum to identify variation in bony elements related to fossorial habits using a morphometrical and biomechanical approach. Diameters and functional lengths of long bones were measured and 10 functional indices were constructed. We found that limb proportions of C. talarum undergo significant changes throughout postnatal ontogeny, and no significant differences between sexes were observed. Five of six forelimb indices and two of four hindlimb indices showed differences between ages. According to discriminant analysis, the indices that contributed most to discrimination among age groups were robustness of the humerus and ulna, relative epicondylar width, crural and brachial indices, and index of fossorial ability (IFA). Particularly, pups could be differentiated from juveniles and adults by more robust humeri and ulnae, wider epicondyles, longer middle limb elements, and a proportionally shorter olecranon. Greater robustness indicated a possible compensation for lower bone stiffness while wider epicondyles may be associated to improved effective forces in those muscles that originate onto them, compensating the lower muscular development. The gradual increase in the IFA suggested a gradual enhancement in the scratch-digging performance due to an improvement in the mechanical advantage of forearm extensors. Middle limb indices were higher in pups than in juveniles-adults, reflecting relatively more gracile limbs in their middle segments, which is in accordance with their incipient fossorial ability. In sum, our results show that in C. talarum some scratch-digging adaptations are already present during early postnatal ontogeny, which suggests that they are prenatally shaped, and other traits develop progressively. The role of early digging behavior as a factor influencing on

  9. The role of the subterranean rodent Ctenomys talarum (Rodentia: Octodontidae) in the life cycle of Taenia taeniaeformis (Cestoda: Taeniidae) in urban environments.

    PubMed

    Rossin, Alejandra; Malizia, Ana I; Denegri, Guillermo M

    2004-06-10

    This work is the first report of subterranean rodent Ctenomys talarum (Rodentia: Octodontidae) as intermediate host of Taenia taeniaeformis in urban areas of Mar de Cobo (Buenos Aires Province, Argentina) and to experimentally reproduce in domestic dogs the adult stage of this parasite. Prevalence, mean abundance and mean intensity of infection with T. taeniaeformis larvae in the liver and peritoneal cavity of C. talarum were 64%, 15.3 and 9.8, respectively. Ten adults of T. taeniaeformis were obtained from experimentally infected dogs. Information about the role of subterranean rodents in the life cycle of this parasite is also given. The above mentioned data indicate that T. taeniaeformis is a frequent parasite of this species of rodents, at least within the study area. Also explanations for the high prevalence of larval forms of this parasite in C. talarum populations are given.

  10. Redescription of Trichuris pampeana (Nematoda: Trichuridae) from the South American subterranean rodent Ctenomys talarum Thomas, 1898 (Rodentia: Octodontidae).

    PubMed

    Rossin, M Alejandra; Malizia, Ana I

    2005-02-01

    Trichuris pampeana Suriano and Navone, 1994 (Nematoda: Trichuridae) is redescribed from voucher specimens from the type host Ctenomys azarae Thomas, 1903 (Rodentia: Octodontidae) and from parasites collected from 2 populations of the subterranean rodent C. talarum Thomas, 1898 from Mar de Cobo and Necochea, Buenos Aires Province, Argentina. After a revision of these nematodes, it was confirmed that the following characters were not considered in the original description: bacillary band, cells from the esophagointestinal junction, ejaculatory duct, vas deferens, adanal papillae, vagina, oviduct, and rectum. Additional information about the spicular sheath, vulva, uteri, and ovary is provided. The morphological features given in this redescription allow to confirm the identity of T. pampeana as a valid species and also to distinguish it more clearly from other species of the genus.

  11. PHA-induced inflammation is not energetically costly in the subterranean rodent Ctenomys talarum (tuco-tucos).

    PubMed

    Merlo, Julieta L; Cutrera, Ana P; Luna, Facundo; Zenuto, Roxana R

    2014-09-01

    Immune activity has been proposed to be associated with substantial costs, due to trade-offs with other functions or activities that share common resources and contribute to an animal's fitness. However, direct estimates of the cost of mounting an immune response are few and have been performed mainly in birds. Thus, further work is needed to clarify the relative costs of different components of the immune system and the role of environmental and life-history traits in modulating the costs of resistance. Within the components of immunity, inflammation is considered to be associated with a larger energetic expenditure. Here, we evaluated the energetic cost of the inflammatory response to phytohemagglutinin (PHA) in a wild population of a subterranean rodent, Ctenomys talarum, and the trade-offs between immune activity and reproduction. C. talarum develops an inflammatory response to PHA, but contrary to our predictions, this response was not associated with an increase in oxygen consumption regardless of reproductive status or sex. Our study shows that an immune challenge may not always result in a detectable energetic cost. We discuss the possibility that other currencies could be underlying the cost, such as micro-or macronutrients requirements, autoimmunity or oxidative stress.

  12. Validation of a radioimmunoassay for measuring testosterone concentrations in plasma samples of the subterranean rodent Ctenomys talarum: outstandingly elevated levels in the wild and the effect of captivity.

    PubMed

    Vera, Federico; Zenuto, Roxana Rita; Antenucci, Carlos Daniel; Busso, Juan Manuel; Marín, Raúl Héctor

    2011-11-01

    We validated the Coat-a-Count radioimmunoassay (RIA) kit for measuring testosterone in plasma samples of the subterranean rodent Ctenomys talarum and evaluated testosterone levels in free-living and captive individuals. The performance of the assay was evaluated by the assessment of parallelism, accuracy and precision. Moreover, the high specificity of the assay antibody was confirmed by high-pressure liquid chromatography with ultraviolet detector, followed by electrospray ionization tandem mass spectrometry. Results indicated that plasma samples have to be treated with heat and diluted before the RIA for the optimization of the assay. Plasma testosterone concentrations in free-living animals were outstandingly elevated (up to 329 ng/mL), which are among the highest ever reported for mammals. On the other hand, captivity produced a 14-fold decrease in plasma testosterone concentrations, emphasizing that very significant changes in the endocrine milieu may occur in wild animals kept under laboratory conditions. Our results place tuco-tucos as an interesting model for the study of androgen regulation in mammals, suggesting that target tissues may have low sensitivity to the testosterone signal and agree with a scenario of elevated levels of sex hormone-binding globulin in plasma.

  13. Graphidioides subterraneus n. sp. (Nematoda: Trichostrongyloidea) from the South American subterranean rodent Ctenomys talarum Thomas, 1898 (Rodentia: Octodontidae).

    PubMed

    Rossin, M A; Timi, J T; Malizia, A I

    2005-06-01

    A new nematode species, Graphidioides subterraneus n. sp., found in the stomach of C. talarum from Argentina is described. The new species more closely resembles G. mazzai Lent & Freitas, 1935, parasite of Galea leucoblephara from Argentina, and G. kravetzi Sutton & Durette-Desset, 1995, parasite of Holochilus brasiliensis from Uruguay. It can be distinguished by shorter spicules, by the shape of the gubernaculum, by shorter uterine branches, and by a different number of ridges of the synlophe all along the body.

  14. Parasitism underground: lice (Insecta: Phthiraptera) from Ctenomys talarum (Rodentia: Ctenomyidae) along its coastal distribution in Argentina.

    PubMed

    Martino, Natalia S; Romero, Mariano D; Malizia, Ana I

    2014-03-01

    Species of South American subterranean rodents belonging to the genus Ctenomys (commonly called tuco-tucos) are widely distributed across the southern Neotropical region. Despite their relatively well-studied biology and reproductive physiology, current knowledge of their ectoparasite fauna is limited to a few ambiguous studies, based on scattered samples from a small number of host individuals. Ctenomys talarum is the most widely distributed species in the genus. Lice (Phthiraptera) were collected from these tuco-tucos throughout their entire coastal range. Two species, one chewing louse (Gyropus parvus), and one sucking louse (Eulinognathus americanus) were collected. The distribution ranges for both louse species were extended with new locality records. No lice were found in two host populations. Furthermore, co-occurrence of both ectoparasites was not detected.

  15. Food Restriction Affects Inflammatory Response and Nutritional State in Tuco-tucos (Ctenomys talarum).

    PubMed

    Merlo, Julieta Leticia; Cutrera, Ana Paula; Zenuto, Roxana Rita

    2016-12-01

    Insufficient or unbalanced food intake typically has a negative impact on immune responses. The understanding of this effect is, however, hampered by the effect that food has on general condition, which, in turn, affects immunity, and the interaction among general condition, immunocompetence, and concurrent infections. The goal of this study was to determine the effects of food restriction and methionine supplementation on immunity in tuco-tucos (Ctenomys talarum). Effects of diet manipulations on nutritional state, inflammatory response to phytohemagglutinin (PHA), and other immune parameters (bacterial killing capacity, natural antibodies, and leukocyte profile) were evaluated. Health and stress parameters and endoparasite loads were assessed to understand more deeply potential effects of treatments on immune status. Individuals under food restriction presented an altered nutritional state as well as increased stress levels (higher N: L ratios) compared with individuals fed ad libitum, and a marked reduction in the inflammatory response to PHA. Supplementation with methionine did not affect any of the parameters analyzed. Endoparasite loads were not affected by treatments. Our results support the idea that food insufficiency can modulate the individual's immune responsiveness through the lack of adequate essential nutrients, metabolic fuel and energetic reserves, or by a detrimental effect of the stress caused by nutrient limitation. We show that the response to PHA previously reported as nonenergetically costly for C. talarum, implies a nutritional cost; an opposite pattern to that previously found for the adaptive antibody response to sheep red blood cells in the same species.

  16. Chromosome synapsis and recombination in simple and complex chromosomal heterozygotes of tuco-tuco (Ctenomys talarum: Rodentia: Ctenomyidae).

    PubMed

    Basheva, Ekaterina A; Torgasheva, Anna A; Gomez Fernandez, Maria Jimena; Boston, Emma; Mirol, Patricia; Borodin, Pavel M

    2014-09-01

    The chromosomal speciation hypothesis suggests that irregularities in synapsis, recombination, and segregation in heterozygotes for chromosome rearrangements may restrict gene flow between karyotypically distinct populations and promote speciation. Ctenomys talarum is a South American subterranean rodent inhabiting the coastal regions of Argentina, whose populations polymorphic for Robertsonian and tandem translocations seem to have a very restricted gene flow. To test if chromosomal differences are involved in isolation among its populations, we examined chromosome pairing, recombination, and meiotic silencing of unsynapsed chromatin in male meiosis of simple and complex translocation heterozygotes using immunolocalization of the MLH1 marking mature recombination nodules and phosphorylated histone γH2A.X marking unrepaired double-strand breaks. We observed small asynaptic areas labeled by γH2A.X in pericentromeric regions of the chromosomes involved in the trivalents and quadrivalents. We also observed a decrease of recombination frequency and a distalization of the crossover distribution in the heterozygotes and metacentric homozygotes compared to acrocentric homozygotes. We suggest that the asynapsis of the pericentromeric regions are unlikely to induce germ cell death and decrease fertility of the heterozygotes; however, suppressed recombination in pericentromeric areas of the multivalents may reduce gene flow between chromosomally different populations of the Talas tuco-tuco.

  17. Homomorphic sex chromosomes and the intriguing Y chromosome of Ctenomys rodent species (Rodentia, Ctenomyidae).

    PubMed

    Suárez-Villota, Elkin Y; Pansonato-Alves, José C; Foresti, Fausto; Gallardo, Milton H

    2014-01-01

    Unlike the X chromosome, the mammalian Y chromosome undergoes evolutionary decay resulting in small size. This sex chromosomal heteromorphism, observed in most species of the fossorial rodent Ctenomys, contrasts with the medium-sized, homomorphic acrocentric sex chromosomes of closely related C. maulinus and C. sp. To characterize the sequence composition of these chromosomes, fluorescent banding, self-genomic in situ hybridization, and fluorescent in situ hybridization with an X painting probe were performed on mitotic and meiotic plates. High molecular homology between the sex chromosomes was detected on mitotic material as well as on meiotic plates immunodetected with anti-SYCP3 and anti-γH2AX. The Y chromosome is euchromatic, poor in repetitive sequences and differs from the X by the loss of a block of pericentromeric chromatin. Inferred from the G-banding pattern, an inversion and the concomitant prevention of recombination in a large asynaptic region seems to be crucial for meiotic X chromosome inactivation. These peculiar findings together with the homomorphism of Ctenomys sex chromosomes are discussed in the light of the regular purge that counteracts Muller's ratchet and the probable mechanisms accounting for their origin and molecular homology.

  18. Modeling Natural Photic Entrainment in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Flôres, Danilo E. F. L.; Tomotani, Barbara M.; Tachinardi, Patricia; Oda, Gisele A.; Valentinuzzi, Veronica S.

    2013-01-01

    Subterranean rodents spend most of the day inside underground tunnels, where there is little daily change in environmental variables. Our observations of tuco-tucos (Ctenomys aff. knighti) in a field enclosure indicated that these animals perceive the aboveground light-dark cycle by several bouts of light-exposure at irregular times during the light hours of the day. To assess whether such light-dark pattern acts as an entraining agent of the circadian clock, we first constructed in laboratory the Phase Response Curve for 1 h light-pulses (1000lux). Its shape is qualitatively similar to other curves reported in the literature and to our knowledge it is the first Phase Response Curve of a subterranean rodent. Computer simulations were performed with a non-linear limit-cycle oscillator subjected to a simple model of the light regimen experienced by tuco-tucos. Results showed that synchronization is achieved even by a simple regimen of a single daily light pulse scattered uniformly along the light hours of the day. Natural entrainment studies benefit from integrated laboratory, field and computational approaches. PMID:23874562

  19. Form and function of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.).

    PubMed

    Amaya, Juan Pablo; Areta, Juan I; Valentinuzzi, Veronica S; Zufiaurre, Emmanuel

    2016-01-01

    The underground environment poses particular communication challenges for subterranean rodents. Some loud and low-pitched acoustic signals that can travel long distances are appropriate for long-range underground communication and have been suggested to be territorial signals. Long-range vocalizations (LRVs) are important in long-distance communication in Ctenomys tuco-tucos. We characterized the LRV of the Anillaco Tuco-Tuco (Ctenomys sp.) using recordings from free-living individuals and described the behavioral context in which this vocalization was produced during laboratory staged encounters between individuals of both sexes. Long-range calls of Anillaco tuco-tucos are low-frequency, broad-band, loud, and long sounds composed by the repetition of two syllable types: series (formed by notes and soft-notes) and individual notes. All vocalizations were initiated with series, but not all had individual notes. Males were heavier than females and gave significantly lower-pitched vocalizations, but acoustic features were independent of body mass in males. The pronounced variation among individuals in the arrangement and number of syllables and the existence of three types of series (dyads, triads, and tetrads), created a diverse collection of syntactic patterns in vocalizations that would provide the opportunity to encode multiple types of information. The existence of complex syntactic patterns and the description of soft-notes represent new aspects of the vocal communication of Ctenomys. Long-distance vocalizations by Anillaco Tuco-Tucos appear to be territorial signals used mostly in male-male interactions. First, emission of LRVs resulted in de-escalation or space-keeping in male-male and male-female encounters in laboratory experiments. Second, these vocalizations were produced most frequently (in the field and in the lab) by males in our study population. Third, males produced LRVs with greater frequency during male-male encounters compared to male

  20. Form and function of long-range vocalizations in a Neotropical fossorial rodent: the Anillaco Tuco-Tuco (Ctenomys sp.)

    PubMed Central

    Valentinuzzi, Veronica S.; Zufiaurre, Emmanuel

    2016-01-01

    The underground environment poses particular communication challenges for subterranean rodents. Some loud and low-pitched acoustic signals that can travel long distances are appropriate for long-range underground communication and have been suggested to be territorial signals. Long-range vocalizations (LRVs) are important in long-distance communication in Ctenomys tuco-tucos. We characterized the LRV of the Anillaco Tuco-Tuco (Ctenomys sp.) using recordings from free-living individuals and described the behavioral context in which this vocalization was produced during laboratory staged encounters between individuals of both sexes. Long-range calls of Anillaco tuco-tucos are low-frequency, broad-band, loud, and long sounds composed by the repetition of two syllable types: series (formed by notes and soft-notes) and individual notes. All vocalizations were initiated with series, but not all had individual notes. Males were heavier than females and gave significantly lower-pitched vocalizations, but acoustic features were independent of body mass in males. The pronounced variation among individuals in the arrangement and number of syllables and the existence of three types of series (dyads, triads, and tetrads), created a diverse collection of syntactic patterns in vocalizations that would provide the opportunity to encode multiple types of information. The existence of complex syntactic patterns and the description of soft-notes represent new aspects of the vocal communication of Ctenomys. Long-distance vocalizations by Anillaco Tuco-Tucos appear to be territorial signals used mostly in male-male interactions. First, emission of LRVs resulted in de-escalation or space-keeping in male-male and male-female encounters in laboratory experiments. Second, these vocalizations were produced most frequently (in the field and in the lab) by males in our study population. Third, males produced LRVs with greater frequency during male-male encounters compared to male

  1. DNA-based and geometric morphometric analysis to validate species designation: a case study of the subterranean rodent Ctenomys bicolor.

    PubMed

    Stolz, J F B; Gonçalves, G L; Leipnitz, L; Freitas, T R O

    2013-10-25

    The genus Ctenomys (Rodentia: Ctenomyidae) shows several taxonomic inconsistencies. In this study, we used an integrative approach including DNA sequences, karyotypes, and geometric morphometrics to evaluate the taxonomic validity of a nominal species, Ctenomys bicolor, which was described based on only one specimen in 1912 by Miranda Ribeiro, and since then neglected. We sampled near the type locality assigned to this species and collected 10 specimens. A total of 820 base pairs of the cytochrome b gene were sequenced and analyzed together with nine other species and four morphotypes obtained from GenBank. Bayesian analyses showed that C. bicolor is monophyletic and related to the Bolivian-Matogrossense group, a clade that originated about 3 mya. We compared the cranial shape through morphometric geometrics of C. bicolor, including the specimen originally sampled in 1912, with other species representative of the same phylogenetic group (C. boliviensis and C. steinbachi). C. bicolor shows unique skull traits that distinguish it from all other currently known taxa. Our findings confirm that the specimen collected by Miranda Ribeiro is a valid species, and improve the knowledge about Ctenomys in the Amazon region.

  2. Rhythmic 24 h Variation of Core Body Temperature and Locomotor Activity in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Tachinardi, Patricia; Bicudo, José Eduardo Wilken; Oda, Gisele Akemi; Valentinuzzi, Verónica Sandra

    2014-01-01

    The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents. PMID:24454916

  3. Rhythmic 24 h variation of core body temperature and locomotor activity in a subterranean rodent (Ctenomys aff. knighti), the tuco-tuco.

    PubMed

    Tachinardi, Patricia; Bicudo, José Eduardo Wilken; Oda, Gisele Akemi; Valentinuzzi, Verónica Sandra

    2014-01-01

    The tuco-tuco Ctenomys aff. knighti is a subterranean rodent which inhabits a semi-arid area in Northwestern Argentina. Although they live in underground burrows where environmental cycles are attenuated, they display robust, 24 h locomotor activity rhythms that are synchronized by light/dark cycles, both in laboratory and field conditions. The underground environment also poses energetic challenges (e.g. high-energy demands of digging, hypoxia, high humidity, low food availability) that have motivated thermoregulation studies in several subterranean rodent species. By using chronobiological protocols, the present work aims to contribute towards these studies by exploring day-night variations of thermoregulatory functions in tuco-tucos, starting with body temperature and its temporal relationship to locomotor activity. Animals showed daily, 24 h body temperature rhythms that persisted even in constant darkness and temperature, synchronizing to a daily light/dark cycle, with highest values occurring during darkness hours. The range of oscillation of body temperature was slightly lower than those reported for similar-sized and dark-active rodents. Most rhythmic parameters, such as period and phase, did not change upon removal of the running wheel. Body temperature and locomotor activity rhythms were robustly associated in time. The former persisted even after removal of the acute effects of intense activity on body temperature by a statistical method. Finally, regression gradients between body temperature and activity were higher in the beginning of the night, suggesting day-night variation in thermal conductance and heat production. Consideration of these day-night variations in thermoregulatory processes is beneficial for further studies on thermoregulation and energetics of subterranean rodents.

  4. Field and Laboratory Studies Provide Insights into the Meaning of Day-Time Activity in a Subterranean Rodent (Ctenomys aff. knighti), the Tuco-Tuco

    PubMed Central

    Tomotani, Barbara M.; Flores, Danilo E. F. L.; Tachinardi, Patrícia; Paliza, José D.; Oda, Gisele A.; Valentinuzzi, Verônica S.

    2012-01-01

    South American subterranean rodents (Ctenomys aff. knighti), commonly known as tuco-tucos, display nocturnal, wheel-running behavior under light-dark (LD) conditions, and free-running periods >24 h in constant darkness (DD). However, several reports in the field suggested that a substantial amount of activity occurs during daylight hours, leading us to question whether circadian entrainment in the laboratory accurately reflects behavior in natural conditions. We compared circadian patterns of locomotor activity in DD of animals previously entrained to full laboratory LD cycles (LD12∶12) with those of animals that were trapped directly from the field. In both cases, activity onsets in DD immediately reflected the previous dark onset or sundown. Furthermore, freerunning periods upon release into DD were close to 24 h indicating aftereffects of prior entrainment, similarly in both conditions. No difference was detected in the phase of activity measured with and without access to a running wheel. However, when individuals were observed continuously during daylight hours in a semi-natural enclosure, they emerged above-ground on a daily basis. These day-time activities consisted of foraging and burrow maintenance, suggesting that the designation of this species as nocturnal might be inaccurate in the field. Our study of a solitary subterranean species suggests that the circadian clock is entrained similarly under field and laboratory conditions and that day-time activity expressed only in the field is required for foraging and may not be time-dictated by the circadian pacemaker. PMID:22649565

  5. The Social Brain: Transcriptome Assembly and Characterization of the Hippocampus from a Social Subterranean Rodent, the Colonial Tuco-Tuco (Ctenomys sociabilis)

    PubMed Central

    MacManes, Matthew D.; Lacey, Eileen A.

    2012-01-01

    Elucidating the genetic mechanisms that underlie complex adaptive phenotypes is a central problem in evolutionary biology. For behavioral biologists, the ability to link variation in gene expression to the occurrence of specific behavioral traits has long been a largely unobtainable goal. Social interactions with conspecifics represent a fundamental component of the behavior of most animal species. Although several studies of mammals have attempted to uncover the genetic bases for social relationships using a candidate gene approach, none have attempted more comprehensive, transcriptome-based analyses using high throughout sequencing. As a first step toward improved understanding of the genetic underpinnings of mammalian sociality, we generated a reference transcriptome for the colonial tuco-tuco (Ctenomys sociabilis), a social species of subterranean rodent that is endemic to southwestern Argentina. Specifically, we analyzed over 500 million Illumina sequencing reads derived from the hippocampi of 10 colonial tuco-tucos housed in captivity under a variety of social conditions. The resulting reference transcriptome provides a critical tool for future studies aimed at exploring relationships between social environment and gene expression in this non-model species of social mammal. PMID:23049809

  6. The role of chromosomal rearrangements and geographical barriers in the divergence of lineages in a South American subterranean rodent (Rodentia: Ctenomyidae: Ctenomys minutus).

    PubMed

    Lopes, C M; Ximenes, S S F; Gava, A; de Freitas, T R O

    2013-10-01

    Identifying factors and the extent of their roles in the differentiation of populations is of great importance for understanding the evolutionary process in which a species is involved. Ctenomys minutus is a highly karyotype-polymorphic subterranean rodent, with diploid numbers ranging from 42 to 50 and autosomal arm numbers (ANs) ranging from 68 to 80, comprising a total of 45 karyotypes described so far. This species inhabits the southern Brazilian coastal plain, which has a complex geological history, with several potential geographical barriers acting on different time scales. We assessed the geographical genetic structure of C. minutus, examining 340 individuals over the entire distributional range and using information from chromosomal rearrangements, mitochondrial DNA (mtDNA) sequences and 14 microsatellite loci. The mtDNA results revealed seven main haplogroups, with the most recent common ancestors dating from the Pleistocene, whereas clustering methods defined 12 populations. Some boundaries of mtDNA haplogroups and population clusters can be associated with potential geographical barriers to gene flow. The isolation-by-distance pattern also has an important role in fine-scale genetic differentiation, which is strengthened by the narrowness of the coastal plain and by common features of subterranean rodents (that is, small fragmented populations and low dispersal rates), which limit gene flow among populations. A step-by-step mechanism of chromosomal evolution can be suggested for this species, mainly associated with the metapopulation structure, genetic drift and the geographical features of the southern Brazilian coastal plain. However, chromosomal variations have no or very little role in the diversification of C. minutus populations.

  7. The role of chromosomal rearrangements and geographical barriers in the divergence of lineages in a South American subterranean rodent (Rodentia: Ctenomyidae: Ctenomys minutus)

    PubMed Central

    Lopes, C M; Ximenes, S S F; Gava, A; de Freitas, T R O

    2013-01-01

    Identifying factors and the extent of their roles in the differentiation of populations is of great importance for understanding the evolutionary process in which a species is involved. Ctenomys minutus is a highly karyotype–polymorphic subterranean rodent, with diploid numbers ranging from 42 to 50 and autosomal arm numbers (ANs) ranging from 68 to 80, comprising a total of 45 karyotypes described so far. This species inhabits the southern Brazilian coastal plain, which has a complex geological history, with several potential geographical barriers acting on different time scales. We assessed the geographical genetic structure of C. minutus, examining 340 individuals over the entire distributional range and using information from chromosomal rearrangements, mitochondrial DNA (mtDNA) sequences and 14 microsatellite loci. The mtDNA results revealed seven main haplogroups, with the most recent common ancestors dating from the Pleistocene, whereas clustering methods defined 12 populations. Some boundaries of mtDNA haplogroups and population clusters can be associated with potential geographical barriers to gene flow. The isolation-by-distance pattern also has an important role in fine-scale genetic differentiation, which is strengthened by the narrowness of the coastal plain and by common features of subterranean rodents (that is, small fragmented populations and low dispersal rates), which limit gene flow among populations. A step-by-step mechanism of chromosomal evolution can be suggested for this species, mainly associated with the metapopulation structure, genetic drift and the geographical features of the southern Brazilian coastal plain. However, chromosomal variations have no or very little role in the diversification of C. minutus populations. PMID:23759727

  8. First record of Viannaiidae (Nematoda: Trichostrongylina) in fossorial rodents (Ctenomys spp.) from Central Argentina, with description of a new genus and species.

    PubMed

    Serrano, Paula Carolina; Digiani, María Celina

    2016-09-14

    A new genus and species of Viannaiidae (Trichostrongylina, Heligmosomoidea), Ischilinema baldoi n. gen. et sp. is described parasitizing two species of tuco-tucos, Ctenomys bergi and Ctenomys rosendopascuali (Rodentia, Hystricomorpha, Ctenomyidae) from Córdoba province, Central Argentina. No helminths were previously known from these two host species. The new genus is defined by the following characters: synlophe with 15 continuous ridges subequal in size, presence of left cuticular dilatation, a gap between ridges 1' and 2', bursa asymmetrical with dorsal ray hypertrophied and displaced to the right, and spicules not twisted. This is the first record of Viannaiidae from the Ctenomyidae, enlarging the host range of these parasites to five out of the 12 extant families of caviomorphs.

  9. Sharing the Space: Distribution, Habitat Segregation and Delimitation of a New Sympatric Area of Subterranean Rodents

    PubMed Central

    Kubiak, Bruno Busnello; Galiano, Daniel; de Freitas, Thales Renato Ochotorena

    2015-01-01

    Subterranean rodents of the genus Ctenomys usually present an allopatric or parapatric distribution. Currently, two cases of sympatry have been recognized for the genus in the coastal dunes of southern Argentina and southern Brazil. In this context, they are ideal models to test hypotheses about the factors that delimit the patterns of space use and to understand interspecific interactions in small mammals. We investigated the vegetation structure, plant biomass and soil hardness selected by two species of subterranean rodents (Ctenomys flamarioni and C. minutus) when distributed in sympatry and allopatry from nine different areas along the line of coastal dunes in southern Brazil. In addition, our work presents a new record of a third area of sympatry for the genus Ctenomys. Ctenomys flamarioni and C. minutus show habitat segregation in the area where they occur in sympatry. These species show segregation in their selection of microhabitats, differing in relation to soil hardness, plant biomass, and plant cover. Ctenomys flamarioni showed a distinction in habitat selection when occurring in allopatry and sympatry, whereas C. minutus selected the same habitat characteristics under both conditions. A possible explanation to the observed pattern is that these species have acquired different adaptations over time which allows them the ability to exploit different resources and thus avoid competitive interactions all together. PMID:25856399

  10. Diversity of tuco-tucos (Ctenomys, Rodentia) in the Northeastern wetlands from Argentina: mitochondrial phylogeny and chromosomal evolution.

    PubMed

    Caraballo, Diego A; Abruzzese, Giselle A; Rossi, María Susana

    2012-06-01

    Tuco-tucos (small subterranean rodents of the genus Ctenomys) that inhabit sandy soils of the area under the influence of the second largest wetland of South America, in Northeastern Argentina (Corrientes province), are a complex of species and forms whose taxonomic status were not defined, nor are the evolutionary relationships among them. The tuco-tuco populations of this area exhibit one of the most ample grades of chromosomal variability within the genus. In order to analyze evolutionary relationships within the Corrientes group and its chromosomal variability, we completed the missing karyotypic information and performed a phylogenetic analysis. We obtained partial sequences of three mitochondrial markers: D-loop, cytochrome b and cytochrome oxidase I. The Corrientes group was monophyletic and split into three main clades that grouped related karyomorphs. The phylogeny suggested an ancestral condition of the karyomorph with diploid number (2n) 70 and fundamental number (FN) 84 that has evolved mainly via reductions of the FN although amplifications occurred in certain lineages. We discuss the relationship between patterns of chromosomal variability and species and groups boundaries. From the three main clades the one named iberá exhibited a remarkable karyotypic homogeneity, and could be considered as an independent and cohesive evolutionary lineage. On the contrary, the former recognized species C. dorbignyi is a polyphyletic lineage and hence its systematic classification should be reviewed.

  11. Carpal-metacarpal specializations for burrowing in South American octodontoid rodents

    PubMed Central

    Morgan, Cecilia C; Verzi, Diego H

    2011-01-01

    Among the ecomorphologically diverse Octodontoidea rodents, fossorial habits are prevalent in Ctenomyidae and Octodontidae and occur in some members of Echimyidae. To detect traits linked to scratch-digging, we analyzed morpho-structural variation in the carpus and metacarpus of 27 species of extinct and living octodontoids with epigean, fossorial and subterranean habits. Within a context of relative morphological uniformity, we detected the following specialized traits in the burrowing Clyomys (Echimyidae), Spalacopus (Octodontidae), Ctenomys and †Eucelophorus (Ctenomyidae): broad shortened carpus, robust metacarpals, markedly broad and short metacarpal V, and predominance of ray III (mesaxony, incipient in Spalacopus). In addition, the specialized subterranean Ctenomys presented an enlarged scapholunar in extensive contact with the unciform, and with a complex-shaped proximal articular surface. These features are interpreted as responses to mechanical requirements of scratch-digging, providing greater carpal rigidity and resistance to direct forces exerted during the digging stroke. In Ctenomys, the radius-scapholunar joint restricts movement at wrist level. The phylogenetic distribution of traits shows that the most derived carpal and metacarpal morphologies occur among subterranean octodontoids, also possessing important craniodental adaptations, and supports the hypothesis that the acquisition of digging specializations would have been linked to increasing burrowing frequency in some lineages. Nevertheless, octodontoids with less morphological specializations have metacarpal modifications advantageous for digging, suggesting that scratch-digging specialization preceded the acquisition of tooth-digging traits, in agreement with the general claim that scratch-digging is the primary digging strategy in burrowing mammals. PMID:21557745

  12. Penial morphology in three species of Brazilian tuco-tucos, Ctenomys torquatus, C. minutus, and C. flamarioni (Rodentia: Ctenomyidae).

    PubMed

    Rocha-Barbosa, O; Bernardo, J S L; Loguercio, M F C; Freitas, T R O; Santos-Mallet, J R; Bidau, C J

    2013-02-01

    The present study analyses the glans penis and baculum morphology of three Brazilian tuco-tucos, Ctenomys torquatus Lichtenstein, 1830, Ctenomys minutus Nehring, 1887 and Ctenomys flamarioni Travi, 1981, in order to identify possible variations and understand some more about this taxonomically complex group. We used fixed penis from 15 previously listed adult specimens. For a more detailed baculum analysis, the penis underwent dissection and diaphanisation, whereas to analyse the glans penis surface we used Scanning Electron Microscopy (SEM). Results showed striking differences in baculum morphology among the three species. While C. minutus have a particular V-shaped proximal baculum tip, C. flamarioni baculum is thin throughout the shaft with rounded proximal and distal tips. Ctenomys torquatus have a shorter and larger baculum, similar to what has previously been described for the species. Glans penis surface microstructure analyses also revealed inter-specific differences, with penial spines varying in shape, size and, especially density. Although C. torquatus has a relatively small penis, it has the largest penial spine density, which suggests a more complex penial ornamentation in this species.

  13. Rodent Control

    ERIC Educational Resources Information Center

    Indian Journal of Adult Education, 1975

    1975-01-01

    Strategies for rodent control in crop fields, threshing yards, and rural residential areas are presented together with an operational plan for implementing a program for rodent control at the national level. Training personnel in rodent control procedures and procedures for educating the public in the necessity for control are covered. (EC)

  14. Ancient DNA reveals Holocene loss of genetic diversity in a South American rodent.

    PubMed

    Chan, Yvonne L; Lacey, Eileen A; Pearson, Oliver P; Hadly, Elizabeth A

    2005-12-22

    Understanding how animal populations have evolved in response to palaeoenvironmental conditions is essential for predicting the impact of future environmental change on current biodiversity. Analyses of ancient DNA provide a unique opportunity to track population responses to prehistoric environments. We explored the effects of palaeoenvironmental change on the colonial tuco-tuco (Ctenomys sociabilis), a highly endemic species of Patagonian rodent that is currently listed as threatened by the IUCN. By combining surveys of modern genetic variation from throughout this species' current geographic range with analyses of DNA samples from fossil material dating back to 10,000 ybp, we demonstrate a striking decline in genetic diversity that is concordant with environmental events in the study region. Our results highlight the importance of non-anthropogenic factors in loss of diversity, including reductions in smaller mammals such as rodents.

  15. Redescription of Gyropus parvus (Ewing, 1924) (Insecta: Phthiraptera: Amblycera: Gyropidae) from tucos-tucos (Rodentia: Ctenomyidae: Ctenomys ) in Patagonia, Argentina.

    PubMed

    Martino, N S; Romero, M D; Castro, D C

    2010-02-01

    A detailed redescription of Gyropus parvus (Insecta: Phthiraptera: Amblycera: Gyropidae) is given based on specimens collected from the type host, Ctenomys colburni Allen 1903 , and the type locality, Estancia Huanuluán, Provincia de Rio Negro, Argentina. We expand and provide new chaetotaxy. New scanning electron microscopy images showing microstructural details of adults and eggs of G. parvus obtained from topotype specimens are included. Sexual dimorphism was mainly shown by differences in body size and abdominal chaetotaxy, with females being 17.5% larger than males and with more setae in each cluster. Significant differences between males and females were also observed in sternal plate measurements. Features described here show homogeneity within type host population. This information contributes to our knowledge of intra- and inter-specific variability for parasite populations. Our investigation constitutes the first collection of G. parvus from the type host and locality since it was described.

  16. Interactions between environmental factors can hide isolation by distance patterns: a case study of Ctenomys rionegrensis in Uruguay

    PubMed Central

    Kittlein, Marcelo J; Gaggiotti, Oscar E

    2008-01-01

    Identifying the factors responsible for the structuring of genetic diversity is of fundamental importance for biodiversity conservation. However, arriving at such understanding is difficult owing to the many factors involved and the potential interactions between them. Here, we present an example of how such interactions can preclude us from arriving at a complete characterization of the demographic history and genetic structure of a species. Ctenomys rionegrensis is a species with restricted dispersal abilities and, as such, should exhibit an isolation by distance (IBD) pattern, which previous studies were unable to uncover. It was therefore concluded that this species underwent a recent population expansion. Using a novel hierarchical Bayesian method, we show that the inability to detect the IBD pattern is due to the interaction between elevation and geographical distance. We posit that populations in low areas suffer periodic floods that may reduce local population sizes, increasing genetic drift, a process that masks the effect of distance on genetic differentiation. Our results do not refute the possibility that the populations of C. rionegrensis underwent a recent population expansion but they indicate that an alternative scenario described by a metapopulation model at or near migration-drift equilibrium cannot be excluded either. PMID:18682369

  17. Rodents And Other Gnawers.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    Presents information about rodents and lagomorphs, including definitions and the characteristics of these animals. Contains teaching activities such as "Habitats for Hoppers,""Cartoon Gnawers," and "The Great Rodent Expedition." Reproducible handouts for two of the activities are provided. (TW)

  18. Rodent Research-1 Validation of Rodent Hardware

    NASA Technical Reports Server (NTRS)

    Globus, Ruth; Beegle, Janet

    2013-01-01

    To achieve novel science objectives, validation of a rodent habitat on ISS will enable - In-flight analyses during long duration spaceflight- Use of genetically altered animals- Application of modern analytical techniques (e.g. genomics, proteomics, and metabolomics)

  19. Influence of environmental heterogeneity on the distribution and persistence of a subterranean rodent in a highly unstable landscape.

    PubMed

    Gómez Fernández, María Jimena; Boston, Emma S M; Gaggiotti, Oscar E; Kittlein, Marcelo J; Mirol, Patricia M

    2016-12-01

    In this study we combine information from landscape characteristics, demographic inference and species distribution modelling to identify environmental factors that shape the genetic distribution of the fossorial rodent Ctenomys. We sequenced the mtDNA control region and amplified 12 microsatellites from 27 populations distributed across the Iberá wetland ecosystem. Hierarchical Bayesian modelling was used to construct phylogenies and estimate divergence times. We developed species distribution models to determine what climatic variables and soil parameters predicted species presence by comparing the current to the historic and predicted future distribution of the species. Finally, we explore the impact of environmental variables on the genetic structure of Ctenomys based on current and past species distributions. The variables that consistently correlated with the predicted distribution of the species and explained the observed genetic differentiation among populations included the distribution of well-drained sandy soils and temperature seasonality. A core region of stable suitable habitat was identified from the Last Interglacial, which is projected to remain stable into the future. This region is also the most genetically diverse and is currently under strong anthropogenic pressure. Results reveal complex demographic dynamics, which have been in constant change in both time and space, and are likely linked to the evolution of the Paraná River. We suggest that any alteration of soil properties (climatic or anthropic) may significantly impact the availability of suitable habitat and consequently the ability of individuals to disperse. The protection of this core stable habitat is of prime importance given the increasing levels of human disturbance across this wetland system and the threat of climate change.

  20. Another one bites the dust: bite force and ecology in three caviomorph rodents (Rodentia, Hystricognathi).

    PubMed

    Becerra, Federico; Echeverría, Alejandra Isabel; Casinos, Adrià; Vassallo, Aldo Iván

    2014-04-01

    Mammals have developed sophisticated strategies adapting to particular locomotor modes, feeding habits, and social interactions. Many rodent species have acquired a fossorial, semi-fossorial, or even subterranean life-style, converging on morphological, anatomical, and ecological features but diverging in the final arrangement. These ecological variations partially depend on the functional morphology of their digging tools. Muscular and mechanical features (e.g., lever arms relationship) of the bite force were analyzed in three caviomorph rodents with similar body size but different habits and ecological demands of the jaws. In vivo forces were measured at incisors' tip using a strain gauge load cell force transducer whereas theoretical maximal performance values, mechanical advantages, and particular contribution of each adductor muscle were estimated from dissections in specimens of Ctenomys australis (subterranean, solitary), Octodon degus (semi-fossorial, social), and Chinchilla laniger (ground-dweller, colonial). Our results showed that C. australis bites stronger than expected given its small size and C. laniger exhibited the opposite outcome, while O. degus is close to the expected value based on mammalian bite force versus body mass regressions; what might be associated to the chisel-tooth digging behavior and social interactions. Our key finding was that no matter how diverse these rodents' skulls were, no difference was found in the mechanical advantage of the main adductor muscles. Therefore, interspecific differences in the bite force might be primarily due to differences in the muscular development and force, as shown for the subterranean, solitary and territorial C. australis versus the more gracile, ground-dweller, and colonial C. laniger.

  1. DNA metabarcoding diet analysis for species with parapatric vs sympatric distribution: a case study on subterranean rodents

    PubMed Central

    Lopes, C M; De Barba, M; Boyer, F; Mercier, C; da Silva Filho, P J S; Heidtmann, L M; Galiano, D; Kubiak, B B; Langone, P; Garcias, F M; Gielly, L; Coissac, E; de Freitas, T R O; Taberlet, P

    2015-01-01

    Closely related sympatric species commonly develop different ecological strategies to avoid competition. Ctenomys minutus and C. flamarioni are subterranean rodents parapatrically distributed in the southern Brazilian coastal plain, showing a narrow sympatric zone. To gain understanding on food preferences and possible competition for food resources, we evaluated their diet composition performing DNA metabarcoding analyzes of 67 C. minutus and 100 C. flamarioni scat samples, collected along the species geographical ranges. Thirteen plant families, mainly represented by Poaceae, Araliaceae, Asteraceae and Fabaceae, were identified in the diet of C. minutus. For C. flamarioni, 10 families were recovered, with a predominance of Poaceae, Araliaceae and Asteraceae. A significant correlation between diet composition and geographical distance was detected in C. minutus, whereas the diet of C. flamarioni was quite homogeneous throughout its geographical distribution. No significant differences were observed between males and females of each species. However, differences in diet composition between species were evident according to multivariate analysis. Our results suggest some level of diet partitioning between C. flamarioni and C. minutus in the sympatric region. While the first species is more specialized on few plant items, the second showed a more varied and heterogeneous diet pattern among individuals. These differences might have been developed to avoid competition in the region of co-occurrence. Resource availability in the environment also seems to influence food choices. Our data indicate that C. minutus and C. flamarioni are generalist species, but that some preference for Poaceae, Asteraceae and Araliaceae families can be suggested for both rodents. PMID:25649502

  2. The largest fossil rodent

    PubMed Central

    Rinderknecht, Andrés; Blanco, R. Ernesto

    2008-01-01

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000 kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2 Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  3. The largest fossil rodent.

    PubMed

    Rinderknecht, Andrés; Blanco, R Ernesto

    2008-04-22

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene-Pleistocene (4-2Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities.

  4. Microdialysis in Rodents

    PubMed Central

    Zapata, Agustin; Chefer, Vladimir I.; Shippenberg, Toni S.

    2010-01-01

    Microdialysis is an in vivo sampling technique that permits the quantification of various substances (e.g., neurotransmitters, peptides, electrolytes) in blood and tissue. It is also used to infuse substances into the brain and spinal cord. This unit describes methods for the construction and stereotaxic implantation of microdialysis probes into discrete brain regions of the rat and mouse. Procedures for the conduct of conventional and quantitative microdialysis experiments in the awake and anesthetized rodent are also provided. PMID:19340813

  5. Rodent models of sleep apnea.

    PubMed

    Davis, Eric M; O'Donnell, Christopher P

    2013-09-15

    Rodent models of sleep apnea have long been used to provide novel insight into the generation and predisposition to apneas as well as to characterize the impact of sleep apnea on cardiovascular, metabolic, and psychological health in humans. Given the significant body of work utilizing rodent models in the field of sleep apnea, the aims of this review are three-fold: first, to review the use of rodents as natural models of sleep apnea; second, to provide an overview of the experimental interventions employed in rodents to simulate sleep apnea; third, to discuss the refinement of rodent models to further our understanding of breathing abnormalities that occur during sleep. Given mounting evidence that sleep apnea impairs cognitive function, reduces quality of life, and exacerbates the course of multiple chronic diseases, rodent models will remain a high priority as a tool to interrogate both the pathophysiology and sequelae of breathing related abnormalities during sleep and to improve approaches to diagnosis and therapy.

  6. Geomagnetic field detection in rodents

    SciTech Connect

    Olcese, J.; Reuss, S.; Semm, P.

    1988-01-01

    In addition to behavioral evidence for the detection of earth-strength magnetic fields (MF) by rodents, recent investigations have revealed that electrophysiological and biochemical responses to MF occur in the pineal organ and retina of rodents. In addition, ferrimagnetic deposits have been identified in the ethmoidal regions of the rodent skull. These findings point to a new sensory phenomenon, which interfaces with many fields of biology, including neuroscience, psychophysics, behavioral ecology, chronobiology and sensory physiology.

  7. Chemotherapy of Rodent Malaria.

    DTIC Science & Technology

    1985-07-01

    15 ML W_____ 1 .5 1.25 1-4 1. j . .. .... AD CHEMOTHERAPY OF RODENT MALARIA /I ’ IFINAL REPORT 00 WALLACE PETERS MD DSc I!JULY 1985 Supported by US...Table 15 and detailed report sheets are appended as Tables 16 through 21. 3.1.1 WR 251855 AA This lepidine, an analogue of primaquine, is very active...in our 15 preliminary test. The remaining three compounds also exhibited toxicity in varying degrees at this dose and, consequently, even the low level

  8. Rodent carcinogens: Setting priorities

    SciTech Connect

    Gold, L.S.; Slone, T.H.; Stern, B.R.; Manley, N.B.; Ames, B.N. )

    1992-10-09

    The human diet contains an enormous background of natural chemicals, such as plant pesticides and the products of cooking, that have not been a focus of carcinogenicity testing. A broadened perspective that includes these natural chemicals is necessary. A comparison of possible hazards for 80 daily exposures to rodent carcinogens from a variety of sources is presented, using an index (HERP) that relates human exposure to carcinogenic potency in rodents. A similar ordering would be expected with the use of standard risk assessment methodology for the same human exposure values. Results indicate that, when viewed against the large background of naturally occurring carcinogens in typical portions of common foods, the residues of synthetic pesticides or environmental pollutants rank low. A similar result is obtained in a separate comparison of 32 average daily exposures to natural pesticides and synthetic pesticides residues in the diet. Although the findings do not indicate that these natural dietary carcinogens are important in human cancer, they cast doubt on the relative importance for human cancer of low-dose exposures to synthetic chemicals.

  9. Aquaporins in desert rodent physiology.

    PubMed

    Pannabecker, Thomas L

    2015-08-01

    Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described.

  10. The allometry of rodent intestines.

    PubMed

    Lovegrove, Barry G

    2010-06-01

    This study examined the allometry of the small intestine, caecum, colon and large intestine of rodents (n = 51) using a phylogenetically informed approach. Strong phylogenetic signal was detected in the data for the caecum, colon and large intestine, but not for the small intestine. Most of the phylogenetic signal could be attributed to clade effects associated with herbivorous versus omnivorous rodents. The herbivorous rodents have longer caecums, colons and large intestines, but their small intestines, with the exception of the desert otomyine rodents, are no different to those of omnivorous rodents. Desert otomyine rodents have significantly shorter small intestines than all other rodents, reflecting a possible habitat effect and providing a partial explanation for the low basal metabolic rates of small desert mammals. However, the desert otomyines do not have shorter colons or large intestines, challenging claims for adaptation to water retention in arid environments. Data for the Arvicolidae revealed significantly larger caecums and colons, and hence longer large intestines, with no compensatory reduction in the length of the small intestine, which may explain how the smallest mammalian herbivores manage to meet the demands of a very high mass-specific metabolic rate. This study provides phylogenetically corrected allometries suitable for future prediction testing.

  11. Oculoscopy in Rabbits and Rodents.

    PubMed

    Jekl, Vladimir; Hauptman, Karel; Knotek, Zdenek

    2015-09-01

    Ophthalmic diseases are common in rabbits and rodents. Fast and definitive diagnosis is imperative for successful treatment of ocular diseases. Ophthalmic examination in rabbits and rodents can be challenging. Oculoscopy offers great magnification for the examination of the ocular structures in such animals, including the evaluation of cornea, anterior eye chamber, limbus, iris, lens, and retina. To date, oculoscopy has been described only sporadically and/or under experimental conditions. This article describes the oculoscopy technique, normal and abnormal ocular findings, and the most common eye disorders diagnosed with the aid of endoscopy in rabbits and rodents.

  12. Rodent Control: Seal Up! Trap Up! Clean Up!

    MedlinePlus

    ... rodent food sources and nesting sites... Diseases from rodents Diseases directly transmitted by rodents Diseases indirectly transmitted by rodents Cleaning up after rodents Take precautions before and during clean up of ...

  13. Rodent empathy and affective neuroscience.

    PubMed

    Panksepp, Jules B; Lahvis, Garet P

    2011-10-01

    In the past few years, several experimental studies have suggested that empathy occurs in the social lives of rodents. Thus, rodent behavioral models can now be developed to elucidate the mechanistic substrates of empathy at levels that have heretofore been unavailable. For example, the finding that mice from certain inbred strains express behavioral and physiological responses to conspecific distress, while others do not, underscores that the genetic underpinnings of empathy are specifiable and that they could be harnessed to develop new therapies for human psychosocial impairments. However, the advent of rodent models of empathy is met at the outset with a number of theoretical and semantic problems that are similar to those previously confronted by studies of empathy in humans. The distinct underlying components of empathy must be differentiated from one another and from lay usage of the term. The primary goal of this paper is to review a set of seminal studies that are directly relevant to developing a concept of empathy in rodents. We first consider some of the psychological phenomena that have been associated with empathy, and within this context, we consider the component processes, or endophenotypes of rodent empathy. We then review a series of recent experimental studies that demonstrate the capability of rodents to detect and respond to the affective state of their social partners. We focus primarily on experiments that examine how rodents share affective experiences of fear, but we also highlight how similar types of experimental paradigms can be utilized to evaluate the possibility that rodents share positive affective experiences. Taken together, these studies were inspired by Jaak Panksepp's theory that all mammals are capable of felt affective experiences.

  14. Guide to Commensal Rodent Control

    DTIC Science & Technology

    1991-12-01

    slaughterhouses. Pigs have been shown to contract trichinosis from infected rat feces in their food. i. Tapeworms - Hymenolepis nana and H. dimanuta...are two of the intestinal parasites transmitted to man by food that has been contaminated with tapeworm - bearing rodent feces. j. Tetanus - The wound

  15. Allometric disparity in rodent evolution

    PubMed Central

    Wilson, Laura A B

    2013-01-01

    In this study, allometric trajectories for 51 rodent species, comprising equal representatives from each of the major clades (Ctenohystrica, Muroidea, Sciuridae), are compared in a multivariate morphospace (=allometric space) to quantify magnitudes of disparity in cranial growth. Variability in allometric trajectory patterns was compared to measures of adult disparity in each clade, and dietary habit among the examined species, which together encapsulated an ecomorphological breadth. Results indicate that the evolution of allometric trajectories in rodents is characterized by different features in sciurids compared with muroids and Ctenohystrica. Sciuridae was found to have a reduced magnitude of inter-trajectory change and growth patterns with less variation in allometric coefficient values among members. In contrast, a greater magnitude of difference between trajectories and an increased variation in allometric coefficient values was evident for both Ctenohystrica and muroids. Ctenohystrica and muroids achieved considerably higher adult disparities than sciurids, suggesting that conservatism in allometric trajectory modification may constrain morphological diversity in rodents. The results provide support for a role of ecology (dietary habit) in the evolution of allometric trajectories in rodents. PMID:23610638

  16. Rodent Oncology: Diseases, Diagnostics, and Therapeutics.

    PubMed

    Hocker, Samuel E; Eshar, David; Wouda, Raelene M

    2017-01-01

    Cancer incidence in rodent species varies dramatically from a common occurrence in mice and rats to just a limited number of documented cases in chinchillas and degus. This article summarizes common tumors, both benign and malignant, that have been reported to occur in rodents. Outlined are clinical signs, diagnostics, and treatments that have been described for rodents presenting with specific neoplasms.

  17. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  18. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  19. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  20. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  1. 21 CFR 1250.96 - Rodent control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Rodent control. 1250.96 Section 1250.96 Food and... SANITATION Sanitation Facilities and Conditions on Vessels § 1250.96 Rodent control. Vessels shall be... of rodent control....

  2. Preclinical imaging anesthesia in rodents.

    PubMed

    Vesce, Giancarlo; Micieli, Fabiana; Chiavaccini, Ludovica

    2017-03-01

    Despite the outstanding progress achieved by preclinical imaging science, laboratory animal anesthesia remains quite stationary. Ninety percent of preclinical imaging studies are carried on small rodents (mice and rats) anesthetized by outdated injectable and/or inhalation agents. A need for imaging awake (conscious) animals is questionably registered mainly for brain research, for phMRI and for accomplishing pain and analgesia studies. A need for improving current rodent anesthesia protocols and for enforcing the 3Rs paradigm is sought. Patient monitoring throughout the procedure and recovery phases, as well as vital parameter's data must be recorded in basic consciousness states and during imaging sessions. A multidrug approach is suggested to overcome the limits of monoanesthesia and well-timed physiological data are required to ground findings and to interpret imaging data.

  3. Identifying Rodent Hantavirus Reservoirs, Brazil

    PubMed Central

    Bisordi, Ivani; Levis, Silvana; Garcia, Jorge; Pereira, Luiz E.; Souza, Renato P.; Sugahara, Teresa K.N.; Pini, Noemi; Enria, Delia; Souza, Luiza T.M.

    2004-01-01

    We describe the genetic analysis of samples from hantavirus pulmonary syndrome (HPS) patients from southern and southeastern states of Brazil and rodents captured at the presumed site of infection of these patients. A total of 65 samples that were antibody-positive for Sin Nombre or Laguna Negra virus by enzyme-linked immunosorbent assay were processed by nested reverse transcription–polymerase chain reaction (RT-PCR) by using several primer combinations in the M and S genome segments. PCR products were amplified and sequenced from samples from 11 HPS patient and 7 rodent samples. Phylogenetic analysis of nucleotide sequence differences showed the cocirculation of Araraquara and Juquitiba-like viruses, previously characterized from humans. Our genetic data indicate that Araraquara virus is associated with Bolomys lasiurus (hairy-tailed Bolo mouse) and the Juquitiba-like virus is associated with Oligoryzomys nigripes (black-footed pigmy rice rat). PMID:15663849

  4. Rodent consumption in Khon Kaen Province, Thailand.

    PubMed

    Suwannarong, Kanokwan; Chapman, Robert S

    2014-09-01

    Rodents are important reservoirs of rodent-borne infections worldwide, including Southeast Asia and Northeast Thailand (Isaan), where rodent consumption may be a source of rodent-borne diseases. The behavior of consuming rodents is related to a population's traditions, knowledge, cultural, and household contexts, among other factors. This cross-sectional survey was conducted in Khon Kaen Province, Thailand during November-December 2011. It aimed to elicit information about rodent consumption among residents of this province, and to identify factors associated with rodent consumption there. Multiple logistic regression analysis indicated that male gender, large family size, and use of rainwater as the main source of drinking water were positively associated with reported rodent consumption in this province, while having proper knowledge/attitudes towards animal-borne disease was negatively associated. These results provide evidence-base information for further studies, such as participatory ac- tion research, to further explore how people interact with rodents in different contexts. Further research is also needed to characterize risk of zoonotic diseases in relation to rodent consumption.

  5. Prospects for biological control of rodent populations*

    PubMed Central

    Wodzicki, Kazimierz

    1973-01-01

    Pathogens and predatory animals are the main agents used for the biological control of rodents. The pathogens that have been used are of the genus Salmonella; none is rodent-specific and all can cause severe infection in man and domestic animals. Furthermore, rodents frequently develop immunity to, and become carriers of, these organisms, and there is little to commend their use, except in lightly populated areas where control is infrequently applied. The relationships of five predator species with their rodent prey have been examined. The monitor lizard, mongoose, and ferret were for different reasons found to be unsatisfactory, and there is not yet sufficient evidence to warrant further releases of the Japanese weasel. Domestic and feral cats control rodents well in some situations but only after some other agent has removed a large part of the rodent population. PMID:4587482

  6. Tactile learning in rodents: Neurobiology and neuropharmacology.

    PubMed

    Roohbakhsh, Ali; Shamsizadeh, Ali; Arababadi, Mohammad Kazemi; Ayoobi, Fateme; Fatemi, Iman; Allahtavakoli, Mohammad; Mohammad-Zadeh, Mohammad

    2016-02-15

    Animal models of learning and memory have been the subject of considerable research. Rodents such as mice and rats are nocturnal animals with poor vision, and their survival depends on their sense of touch. Recent reports have shown that whisker somatosensation is the main channel through which rodents collect and process environmental information. This review describes tactile learning in rodents from a neurobiological and neuropharmacological perspective, and how this is involved in memory-related processes.

  7. Prediction of rodent carcinogenicity for 30 chemicals

    SciTech Connect

    Ashby, J.

    1996-10-01

    Predictions of carcinogenic activity are made for 30 chemicals currently being assessed for rodent carcinogenicity by the U.S. National Toxicology Program. The predictions are based upon the chemical structure, the anticipated or reported mutagenicity, and the reported sub-chronic toxicity of each chemical. It is predicted that 13 chemicals will be noncarcinogenic to rodents, that 7 will be genotoxic carcinogens, and that 10 may show some evidence of presumed nongenotoxic rodent carcinogenesis. 3 refs., 1 fig.

  8. Urban resident attitudes toward rodents, rodent control products, and environmental effects

    EPA Science Inventory

    Rodent control in urban areas can result in the inadvertent mortality of non-target species (e.g., bobcats). However, there is little detailed information about rodent control practices of urban residents. Our objective was to evaluate urban rodent control behaviors in two area...

  9. Rodent models for human diseases.

    PubMed

    Vandamme, Thierry F

    2015-07-15

    One of the factors limiting the translation of knowledge from preclinical studies to the clinic has been the limitations of in vivo diseases models. Except in the case of highly controlled and regulated clinical trials, geneticists and scientists do not use humans for their experimental investigations because of the obvious risk to life. Instead, they use various animal, fungal, bacterial, and plant species as model organisms for their studies. Amongst these model organisms, rodent models are the most used due to the easiness for the experiments and the possibility to modify genetically these model animals. Nevertheless, due to the fact that animal models typically do not contract the same genetic diseases as people, so scientists must alter their genomes to induce human disease states and to know what kind of mutation causes the disease. In this brief review, we will discuss the interests of rodent models that have been developed to simulate human pathologies, focusing in models that employ xenografts and genetic modification. Within the framework of genetically engineered mouse (GEM) models, we will review some of the current genetic strategies for modeling diseases.

  10. Hantavirus Prevention: Cleanup of Rodent Contamination

    DTIC Science & Technology

    2008-09-01

    Hantaviruses in the Americas may cause human disease involving the lungs, hence the name " hantavirus pulmonary syndrome" (HPS). Since May 1993, a...humans are also found in other rodents, but the number of cases stemming from these hantaviruses is small when compared to SNV. Hantavirus is shed in... HANTAVIRUS PREVENTION: CLEANUP OF RODENT CONTAMINATION Technical Information Paper 18-001-0306

  11. Rodents: food or pests in Neolithic Orkney.

    PubMed

    Romaniuk, Andrzej A; Shepherd, Alexandra N; Clarke, David V; Sheridan, Alison J; Fraser, Sheena; Bartosiewicz, László; Herman, Jeremy S

    2016-10-01

    Rodents have important effects on contemporary human societies, sometimes providing a source of food but more often as agricultural pests, or as vectors and reservoirs of disease. Skeletal remains of rodents are commonly found in archaeological assemblages from around the world, highlighting their potential importance to ancient human populations. However, there are few studies of the interactions between people and rodents at such sites and most of these are confined to locations where rodents have formed a part of the recent diet. Here we compare the accumulation pattern of rodent remains from four locations within and adjacent to the renowned Neolithic site of Skara Brae, Orkney, showing that those within the settlement itself were the result of deliberate human activity. The accumulation and nature of burnt bones, incorporated over an extended period within deposits of household waste, indicate that rodents were used as a nutritional resource and may have been the subject of early pest control. We, therefore, provide the first evidence for the exploitation or control of rodents by the Neolithic inhabitants of Europe.

  12. Rodents: food or pests in Neolithic Orkney

    PubMed Central

    Romaniuk, Andrzej A.; Shepherd, Alexandra N.; Clarke, David V.; Sheridan, Alison J.; Fraser, Sheena; Bartosiewicz, László

    2016-01-01

    Rodents have important effects on contemporary human societies, sometimes providing a source of food but more often as agricultural pests, or as vectors and reservoirs of disease. Skeletal remains of rodents are commonly found in archaeological assemblages from around the world, highlighting their potential importance to ancient human populations. However, there are few studies of the interactions between people and rodents at such sites and most of these are confined to locations where rodents have formed a part of the recent diet. Here we compare the accumulation pattern of rodent remains from four locations within and adjacent to the renowned Neolithic site of Skara Brae, Orkney, showing that those within the settlement itself were the result of deliberate human activity. The accumulation and nature of burnt bones, incorporated over an extended period within deposits of household waste, indicate that rodents were used as a nutritional resource and may have been the subject of early pest control. We, therefore, provide the first evidence for the exploitation or control of rodents by the Neolithic inhabitants of Europe. PMID:27853568

  13. Can rodents conceive hyperbolic spaces?

    PubMed

    Urdapilleta, Eugenio; Troiani, Francesca; Stella, Federico; Treves, Alessandro

    2015-06-06

    The grid cells discovered in the rodent medial entorhinal cortex have been proposed to provide a metric for Euclidean space, possibly even hardwired in the embryo. Yet, one class of models describing the formation of grid unit selectivity is entirely based on developmental self-organization, and as such it predicts that the metric it expresses should reflect the environment to which the animal has adapted. We show that, according to self-organizing models, if raised in a non-Euclidean hyperbolic cage rats should be able to form hyperbolic grids. For a given range of grid spacing relative to the radius of negative curvature of the hyperbolic surface, such grids are predicted to appear as multi-peaked firing maps, in which each peak has seven neighbours instead of the Euclidean six, a prediction that can be tested in experiments. We thus demonstrate that a useful universal neuronal metric, in the sense of a multi-scale ruler and compass that remain unaltered when changing environments, can be extended to other than the standard Euclidean plane.

  14. Modeling panic disorder in rodents.

    PubMed

    Moreira, Fabrício A; Gobira, Pedro H; Viana, Thércia G; Vicente, Maria A; Zangrossi, Hélio; Graeff, Frederico G

    2013-10-01

    Panic disorder (PD) is a subtype of anxiety disorder in which the core phenomenon is the spontaneous occurrence of panic attacks. Although studies with laboratory animals have been instrumental for the understanding of its neurobiology and treatment, few review articles have focused on the validity of the currently used animal models for studying this psychopathology. Therefore, the aim of the present paper is to discuss the strengths and limits of these models in terms of face, construct and predictive validity. Based on the hypothesis that panic attacks are related to defensive responses elicited by proximal threat, most animal models measure the escape responses induced by specific stimuli. Some apply electrical or chemical stimulation to brain regions proposed to modulate fear and panic responses, such as the dorsal periaqueductal grey or the medial hypothalamus. Other models focus on the behavioural consequences caused by the exposure of rodents to ultrasound or natural predators. Finally, the elevated T-maze associates a one-way escape response from an open arm with panic attacks. Despite some limitations, animal models are essential for a better understanding of the neurobiology and pharmacology of PD and for discovering more effective treatments.

  15. Can rodents conceive hyperbolic spaces?

    PubMed Central

    Urdapilleta, Eugenio; Troiani, Francesca; Stella, Federico; Treves, Alessandro

    2015-01-01

    The grid cells discovered in the rodent medial entorhinal cortex have been proposed to provide a metric for Euclidean space, possibly even hardwired in the embryo. Yet, one class of models describing the formation of grid unit selectivity is entirely based on developmental self-organization, and as such it predicts that the metric it expresses should reflect the environment to which the animal has adapted. We show that, according to self-organizing models, if raised in a non-Euclidean hyperbolic cage rats should be able to form hyperbolic grids. For a given range of grid spacing relative to the radius of negative curvature of the hyperbolic surface, such grids are predicted to appear as multi-peaked firing maps, in which each peak has seven neighbours instead of the Euclidean six, a prediction that can be tested in experiments. We thus demonstrate that a useful universal neuronal metric, in the sense of a multi-scale ruler and compass that remain unaltered when changing environments, can be extended to other than the standard Euclidean plane. PMID:25948611

  16. Orthopox virus infections in Eurasian wild rodents.

    PubMed

    Kinnunen, Paula M; Henttonen, Heikki; Hoffmann, Bernd; Kallio, Eva R; Korthase, Christian; Laakkonen, Juha; Niemimaa, Jukka; Palva, Airi; Schlegel, Mathias; Ali, Hanan Sheikh; Suominen, Paula; Ulrich, Rainer G; Vaheri, Antti; Vapalahti, Olli

    2011-08-01

    The genus Orthopoxvirus includes variola (smallpox) virus and zoonotic cowpox virus (CPXV). All orthopoxviruses (OPV) are serologically cross-reactive and cross-protective, and after the cessation of smallpox vaccination, CPXV and other OPV infections represent an emerging threat to human health. In this respect CPXV, with its reservoir in asymptomatically infected wild rodents, is of special importance. In Europe, clinical cowpox has been diagnosed in both humans and animals. The main objective of this study was to elucidate the prevalence of OPV infections in wild rodents in different parts of Eurasia and to compare the performance of three real-time polymerase chain reaction (PCR) methods in detecting OPV DNA in wildlife samples. We investigated 962 wild rodents from Northern Europe (Finland), Central Europe (Germany), and Northern Asia (Siberia, Russia) for the presence of OPV antibodies. According to a CPXV antigen-based immunofluorescence assay, animals from 13 of the 17 locations (76%) showed antibodies. Mean seroprevalence was 33% in Finland (variation between locations 0%-69%), 32% in Germany (0%-43%), and 3.2% (0%-15%) in Siberia. We further screened tissue samples from 513 of the rodents for OPV DNA using up to three real-time PCRs. Three rodents from two German and one Finnish location were OPV DNA positive. The amplicons were 96% to 100% identical to available CPXV sequences. Further, we demonstrated OPV infections as far east as the Baikal region and occurring in hamster and two other rodent species, ones previously unnoticed as possible reservoir hosts. Based on serological and PCR findings, Eurasian wild rodents are frequently but nonpersistently infected with OPVs. Results from three real-time PCR methods were highly concordant. This study extends the geographic range and wildlife species diversity in which OPV (or CPXV) viruses are naturally circulating.

  17. The MAM rodent model of schizophrenia

    PubMed Central

    Lodge, Daniel J.

    2013-01-01

    Rodent models of human disease are essential to obtain a better understanding of disease pathology, the mechanism of action underlying conventional treatments, as well as for the generation of novel therapeutic approaches. There are a number of rodent models of schizophrenia based on either genetic manipulations, acute or sub-chronic drug administration, or developmental disturbances. The prenatal methylazoxymethanol acetate (MAM) rodent model is a developmental disruption model gaining increased attention because it displays a number of histological, neurophysiological and behavioral deficits analogous to those observed in schizophrenia patients. This unit describes the procedures required to safely induce the MAM phenotype in rats. In addition, we describe a simple behavioral procedure, amphetamine-induced hyper-locomotion, which can be utilized to verify the MAM phenotype. PMID:23559309

  18. Behavioral and mechanistic insight into rodent empathy.

    PubMed

    Sivaselvachandran, Sivaani; Acland, Erinn L; Abdallah, Salsabil; Martin, Loren J

    2016-06-14

    Empathy is a psychological construct that allows individuals to understand and share the emotions of others. The ability to share emotional states relies on basic social mechanisms, such as mimicry and emotional contagion, which are considered building blocks for empathy. Mimicking another's emotional or physical state is essential for successful social interactions and is found in a number of animal species. For the current review we focus on emotional state sharing in rodents, a core feature of empathy that is often measured using pain and fear as proxies; we also discuss prosociality in rodents. The evidence for empathy in rodents shows that rats and mice consistently imitate arousal states and behaviors of conspecifics and will even sacrifice personal gain to relieve the distress of a conspecific. These behaviors support basic processes that are crucial for the survival of individual animals and give us insight into the neural mechanisms that govern empathy-related behaviors.

  19. Endoparasites of Wild Rodents in Southeastern Iran

    PubMed Central

    Nateghpour, Mehdi; Motevalli-Haghi, Afsaneh; Akbarzadeh, Kamran; Akhavan, Amir Ahmad; Mohebali, Mehdi; Mobedi, Iraj; Farivar, Leila

    2015-01-01

    Background: This study was aimed to collect wild rodents for endoparasites determination in some parts of Sistan and Baluchistan Province, southeastern Iran nearby Pakistan and Afghanistan countries. Methods: A total of 100 wild rodents were captured alive with cage traps. Various samples were collected from blood and feces, also impression smear prepared from different organs. The samples were prepared by formalin-ether or stained with Giemsa, after that were examined under microscope. Results: All the caught rodents (47 Tatera indica, 44 Meriones hurriana, 5 Gerbilus nanus and 4 Meriones libycus) were studied for endoparasites emphasizing to their zoonotic aspects. Endoparasites including Spirurida, Hymenolepis diminuta, Hymenolepis nana feraterna, Trichuris trichiura, Skerjabino taenia, Trichostrongylus spp, Entamoeba muris, Chilomastix mesnili and Leishmania spp were parasitologically identified. Conclusion: Among 9 genera or species of the identified parasites at least 5 of them have zoonotic and public health importance. PMID:26114139

  20. [Application of genetic diversity in the researches on rodents].

    PubMed

    Liu, Zhu; Yang, Chun-Wen; Xu, Yan-Chun; Jin, Zhi-Min; Ma, Jian-Zhang

    2014-02-01

    Genetic diversity is the base of the species diversity and ecosystem diversity, and also the foundation for biological evolution and species differentiation. Furthermore, genetic diversity is important evidence for evaluation of biological resources of nature. The genetic diversity data from a wide variety of rodents have many complex applications. We summarized the application of rodent prevention, the origin and differentiation including evolutionary history of rodents, the potential adaptation of rodents, the dynamics of population and regulatory mechanisms, and the conservation biology of rodents. Researches in the future should focus on the systematic study on the relationships between population dynamics and genetic diversity, and long-term monitoring of genetic diversity of rodents.

  1. Understanding arid environments using fossil rodent middens

    USGS Publications Warehouse

    Pearson, S.; Betancourt, J.L.

    2002-01-01

    American rodent middens have made a more dramatic contribution to understanding past environments and the development of ecological theory than Australian rodent middens. This relates to differences in the natural environment, the landscape histories, the scale and scientific approaches of the researchers. The comparison demonstrates: the power of synoptic perspectives; the value of thorough macrofossil identification in midden analysis and its potential advance in Australia where pollen has dominated analyses, the value of herbaria and reference collections; the potential of environmental databases; the importance of scientific history and 'critical research mass' and; finally, the opportunistic nature of palaeoecological research. ?? 2002 Elsevier Science Ltd.

  2. Object Recognition Memory and the Rodent Hippocampus

    ERIC Educational Resources Information Center

    Broadbent, Nicola J.; Gaskin, Stephane; Squire, Larry R.; Clark, Robert E.

    2010-01-01

    In rodents, the novel object recognition task (NOR) has become a benchmark task for assessing recognition memory. Yet, despite its widespread use, a consensus has not developed about which brain structures are important for task performance. We assessed both the anterograde and retrograde effects of hippocampal lesions on performance in the NOR…

  3. Conjunctival lymphoid follicles in new world rodents.

    PubMed

    Astley, Roger A; Chodosh, James; Caire, William; Wilson, Gregory M

    2007-09-01

    We report for the first time, the detection of conjunctival lymphoid follicles (CLF) in the eyes of New World rodents. CLF were found in 7 of the 15 species examined, 6 of the 10 genera, and in at least one individual in four families of rodents. These follicles are dense collections of leukocytes in the conjunctival substantia propria with a thinned overlying epithelium lacking in goblet cells. Although the precise location of CLF within the conjunctiva varied from species to species, all CLF were found in the fornix of the conjunctival sac. In general, size and complexity of CLF varied with the size of the eye; the larger the eye, the larger and more complex the CLF. Our findings also reveal that some species of New World rodents, like the majority of Old World rodents examined in this and previous studies might lack CLF. However, until larger samples are examined, this is difficult to state with certainty. Consequently, the presence/absence of CLF at this point might not be informative for phylogenetic comparisons. Our findings also suggest the deer mouse, Peromyscus maniculatus, might serve as a useful model species for studying ocular infections and immunology of the eye.

  4. Options for Dealing With Rodent Infestations

    EPA Pesticide Factsheets

    After removing sources of food and water and shelter, your next options are rodent traps and poisons (rodenticides). Rat or mouse traps may be lethal (snap traps) or live (cage-type), and poison baits must be placed in tamper-resistant bait stations.

  5. 7 CFR 58.147 - Insect and rodent control program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Insect and rodent control program. 58.147 Section 58... Service 1 Operations and Operating Procedures § 58.147 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control...

  6. 20 CFR 654.415 - Insect and rodent control.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Insect and rodent control. 654.415 Section 654.415 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SPECIAL... Insect and rodent control. Housing and facilities shall be free of insects, rodents, and other vermin....

  7. 7 CFR 58.247 - Insect and rodent control program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Insect and rodent control program. 58.247 Section 58... Service 1 Operations and Operating Procedures § 58.247 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control program...

  8. Arenavirus Diversity and Phylogeography of Mastomys natalensis Rodents, Nigeria

    PubMed Central

    Obadare, Adeoba; Oyeyiola, Akinlabi; Igbokwe, Joseph; Fasogbon, Ayobami; Igbahenah, Felix; Ortsega, Daniel; Asogun, Danny; Umeh, Prince; Vakkai, Innocent; Abejegah, Chukwuyem; Pahlman, Meike; Becker-Ziaja, Beate; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-01-01

    Mastomys natalensis rodents are natural hosts for Lassa virus (LASV). Detection of LASV in 2 mitochondrial phylogroups of the rodent near the Niger and Benue Rivers in Nigeria underlines the potential for LASV emergence in fresh phylogroups of this rodent. A Mobala-like sequence was also detected in eastern Nigeria. PMID:26982388

  9. 7 CFR 58.147 - Insect and rodent control program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Insect and rodent control program. 58.147 Section 58... Service 1 Operations and Operating Procedures § 58.147 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control...

  10. 20 CFR 654.415 - Insect and rodent control.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Insect and rodent control. 654.415 Section 654.415 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SPECIAL... Insect and rodent control. Housing and facilities shall be free of insects, rodents, and other vermin....

  11. Arenavirus Diversity and Phylogeography of Mastomys natalensis Rodents, Nigeria.

    PubMed

    Olayemi, Ayodeji; Obadare, Adeoba; Oyeyiola, Akinlabi; Igbokwe, Joseph; Fasogbon, Ayobami; Igbahenah, Felix; Ortsega, Daniel; Asogun, Danny; Umeh, Prince; Vakkai, Innocent; Abejegah, Chukwuyem; Pahlman, Meike; Becker-Ziaja, Beate; Günther, Stephan; Fichet-Calvet, Elisabeth

    2016-04-01

    Mastomys natalensis rodents are natural hosts for Lassa virus (LASV). Detection of LASV in 2 mitochondrial phylogroups of the rodent near the Niger and Benue Rivers in Nigeria underlines the potential for LASV emergence in fresh phylogroups of this rodent. A Mobala-like sequence was also detected in eastern Nigeria.

  12. 7 CFR 58.147 - Insect and rodent control program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Insect and rodent control program. 58.147 Section 58... Service 1 Operations and Operating Procedures § 58.147 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control...

  13. 7 CFR 58.147 - Insect and rodent control program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Insect and rodent control program. 58.147 Section 58... Service 1 Operations and Operating Procedures § 58.147 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control...

  14. 20 CFR 654.415 - Insect and rodent control.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 3 2013-04-01 2013-04-01 false Insect and rodent control. 654.415 Section 654.415 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SPECIAL... Insect and rodent control. Housing and facilities shall be free of insects, rodents, and other vermin....

  15. 7 CFR 58.247 - Insect and rodent control program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Insect and rodent control program. 58.247 Section 58... Service 1 Operations and Operating Procedures § 58.247 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control program...

  16. 7 CFR 58.247 - Insect and rodent control program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Insect and rodent control program. 58.247 Section 58... Service 1 Operations and Operating Procedures § 58.247 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control program...

  17. 7 CFR 58.247 - Insect and rodent control program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Insect and rodent control program. 58.247 Section 58... Service 1 Operations and Operating Procedures § 58.247 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control program...

  18. 20 CFR 654.415 - Insect and rodent control.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Insect and rodent control. 654.415 Section 654.415 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SPECIAL... Insect and rodent control. Housing and facilities shall be free of insects, rodents, and other vermin....

  19. 7 CFR 58.147 - Insect and rodent control program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Insect and rodent control program. 58.147 Section 58... Service 1 Operations and Operating Procedures § 58.147 Insect and rodent control program. In addition to... made responsible for the performance of a regularly scheduled insect and rodent control...

  20. 20 CFR 654.415 - Insect and rodent control.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Insect and rodent control. 654.415 Section 654.415 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR SPECIAL... Insect and rodent control. Housing and facilities shall be free of insects, rodents, and other vermin....

  1. Molecular epidemiology of paramyxoviruses in Zambian wild rodents and shrews.

    PubMed

    Sasaki, Michihito; Muleya, Walter; Ishii, Akihiro; Orba, Yasuko; Hang'ombe, Bernard M; Mweene, Aaron S; Moonga, Ladslav; Thomas, Yuka; Kimura, Takashi; Sawa, Hirofumi

    2014-02-01

    Rodents and shrews are known to harbour various viruses. Paramyxoviruses have been isolated from Asian and Australian rodents, but little is known about them in African rodents. Recently, previously unknown paramyxovirus sequences were found in South African rodents. To date, there have been no reports related to the presence and prevalence of paramyxoviruses in shrews. We found a high prevalence of paramyxoviruses in wild rodents and shrews from Zambia. Semi-nested reverse transcription-PCR assays were used to detect paramyxovirus RNA in 21 % (96/462) of specimens analysed. Phylogenetic analysis revealed that these viruses were novel paramyxoviruses and could be classified as morbillivirus- and henipavirus-related viruses, and previously identified rodent paramyxovirus-related viruses. Our findings suggest the circulation of previously unknown paramyxoviruses in African rodents and shrews, and provide new information regarding the geographical distribution and genetic diversity of paramyxoviruses.

  2. Gait Analysis Methods for Rodent Models of Osteoarthritis

    PubMed Central

    Jacobs, Brittany Y.; Kloefkorn, Heidi E.; Allen, Kyle D.

    2014-01-01

    Patients with osteoarthritis (OA) primarily seek treatment due to pain and disability, yet the primary endpoints for rodent OA models tend to be histological measures of joint destruction. The discrepancy between clinical and preclinical evaluations is problematic, given that radiographic evidence of OA in humans does not always correlate to the severity of patient-reported symptoms. Recent advances in behavioral analyses have provided new methods to evaluate disease sequelae in rodents. Of particular relevance to rodent OA models are methods to assess rodent gait. While obvious differences exist between quadrupedal and bipedal gait sequences, the gait abnormalities seen in humans and in rodent OA models reflect similar compensatory behaviors that protect an injured limb from loading. The purpose of this review is to describe these compensations and current methods used to assess rodent gait characteristics, while detailing important considerations for the selection of gait analysis methods in rodent OA models. PMID:25160712

  3. Gait analysis methods for rodent models of osteoarthritis.

    PubMed

    Jacobs, Brittany Y; Kloefkorn, Heidi E; Allen, Kyle D

    2014-10-01

    Patients with osteoarthritis (OA) primarily seek treatment due to pain and disability, yet the primary endpoints for rodent OA models tend to be histological measures of joint destruction. The discrepancy between clinical and preclinical evaluations is problematic, given that radiographic evidence of OA in humans does not always correlate to the severity of patient-reported symptoms. Recent advances in behavioral analyses have provided new methods to evaluate disease sequelae in rodents. Of particular relevance to rodent OA models are methods to assess rodent gait. While obvious differences exist between quadrupedal and bipedal gait sequences, the gait abnormalities seen in humans and in rodent OA models reflect similar compensatory behaviors that protect an injured limb from loading. The purpose of this review is to describe these compensations and current methods used to assess rodent gait characteristics, while detailing important considerations for the selection of gait analysis methods in rodent OA models.

  4. Changes in tau phosphorylation in hibernating rodents.

    PubMed

    León-Espinosa, Gonzalo; García, Esther; García-Escudero, Vega; Hernández, Félix; Defelipe, Javier; Avila, Jesús

    2013-07-01

    Tau is a cytoskeletal protein present mainly in the neurons of vertebrates. By comparing the sequence of tau molecule among different vertebrates, it was found that the variability of the N-terminal sequence in tau protein is higher than that of the C-terminal region. The N-terminal region is involved mainly in the binding of tau to cellular membranes, whereas the C-terminal region of the tau molecule contains the microtubule-binding sites. We have compared the sequence of Syrian hamster tau with the sequences of other hibernating and nonhibernating rodents and investigated how differences in the N-terminal region of tau could affect the phosphorylation level and tau binding to cell membranes. We also describe a change, in tau phosphorylation, on a casein kinase 1 (ck1)-dependent site that is found only in hibernating rodents. This ck1 site seems to play an important role in the regulation of tau binding to membranes.

  5. Rodent models of TDP-43: Recent advances

    PubMed Central

    Tsao, William; Jeong, Yun Ha; Lin, Sophie; Ling, Jonathan; Price, Donald L.; Chiang, Po-Min; Wong, Philip C.

    2013-01-01

    Recently, missense mutations in the gene TARDBP encoding TDP-43 have been linked to familial ALS. The discovery of genes encoding these RNA binding proteins, such as TDP-43 and FUS/TLS, raised the notion that altered RNA metabolism is a major factor underlying the pathogenesis of ALS. To begin to unravel how mutations in TDP-43 cause dysfunction and death of motor neurons, investigators have employed both gain- and loss-of-function studies in rodent model systems. Here, we will summarize major findings from the initial sets of TDP-43 transgenic and knockout rodent models, identify their limitations, and point to future directions toward clarification of disease mechanism(s) and testing of therapeutic strategies that ultimately may lead to novel therapy for this devastating disease. PMID:22608070

  6. Anaplasma phagocytophilum from Rodents and Sheep, China

    PubMed Central

    Zhan, Lin; Jiang, Jia-Fu; Zhang, Xiao-Ai; Liu, Yun-Xi; Wu, Xiao-Ming; Zhang, Wen-Yi; Zhang, Pan-He; Bian, Chang-Ling; Dumler, J. Stephen; Yang, Hong; Zuo, Shu-Qing; Chu, Chen-Yi; Liu, Wei; Richardus, Jan H.; Habbema, J. Dik F.

    2010-01-01

    To characterize the strains of Anaplasma phagocytophilum in wild and domestic animals in China, we isolated the organism from rodents and sheep in northeastern China. We isolated 3 strains (2 from rodents and 1 from sick sheep) through propagation in BALB/c mice and then cell culture in HL60 cells. The 3 isolates were identified by Wright-Giemsa staining, immunofluorescence, and electronic microscopy and were characterized by sequence analyses of the 16S rRNA gene, partial citrate synthase gene, major surface protein 4 gene, and heat shock protein gene. The multiple sequences of the 3 isolates were identical to each other but different from all known strains from other countries. The public health and veterinary relevance of the isolates deserves further investigation. PMID:20409364

  7. MRI of neuronal plasticity in rodent models.

    PubMed

    Pelled, Galit

    2011-01-01

    Modifications in the behavior and architecture of neuronal networks are well documented to occur in association with learning and memory, as well as following injury. These plasticity mechanisms are crucial to ensure adequate processing of stimuli, and they also dictate the degree of recovery following peripheral or central nervous system injury. Nevertheless, the underlying neuronal mechanisms that determine the degree of plasticity of neuronal pathways are not fully understood. Recent developments in animal-dedicated magnetic resonance imaging (MRI) scanners and related hardware afford a high spatial and temporal resolution, making functional MRI and manganese-enhanced MRI emerging tools for studying reorganization of neuronal pathways in rodent models. Many of the observed changes in neuronal functions in rodent's brains following injury discussed here agree with clinical human fMRI findings. This demonstrates that animal model imaging can have a significant clinical impact in the neuronal plasticity and rehabilitation arenas.

  8. Learning in the Rodent Motor Cortex.

    PubMed

    Peters, Andrew J; Liu, Haixin; Komiyama, Takaki

    2017-03-31

    The motor cortex is far from a stable conduit for motor commands and instead undergoes significant changes during learning. An understanding of motor cortex plasticity has been advanced greatly using rodents as experimental animals. Two major focuses of this research have been on the connectivity and activity of the motor cortex. The motor cortex exhibits structural changes in response to learning, and substantial evidence has implicated the local formation and maintenance of new synapses as crucial substrates of motor learning. This synaptic reorganization translates into changes in spiking activity, which appear to result in a modification and refinement of the relationship between motor cortical activity and movement. This review presents the progress that has been made using rodents to establish the motor cortex as an adaptive structure that supports motor learning. Expected final online publication date for the Annual Review of Neuroscience Volume 40 is July 8, 2017. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

  9. Rodent reservoirs of future zoonotic diseases.

    PubMed

    Han, Barbara A; Schmidt, John Paul; Bowden, Sarah E; Drake, John M

    2015-06-02

    The increasing frequency of zoonotic disease events underscores a need to develop forecasting tools toward a more preemptive approach to outbreak investigation. We apply machine learning to data describing the traits and zoonotic pathogen diversity of the most speciose group of mammals, the rodents, which also comprise a disproportionate number of zoonotic disease reservoirs. Our models predict reservoir status in this group with over 90% accuracy, identifying species with high probabilities of harboring undiscovered zoonotic pathogens based on trait profiles that may serve as rules of thumb to distinguish reservoirs from nonreservoir species. Key predictors of zoonotic reservoirs include biogeographical properties, such as range size, as well as intrinsic host traits associated with lifetime reproductive output. Predicted hotspots of novel rodent reservoir diversity occur in the Middle East and Central Asia and the Midwestern United States.

  10. Bats and Rodents Shape Mammalian Retroviral Phylogeny.

    PubMed

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-11-09

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general.

  11. Cage allocation designs for rodent carcinogenicity experiments

    PubMed Central

    Herzberg, Agnes M.; Lagakos, Stephen W.

    1991-01-01

    Cage allocation designs for rodent carcinogenicity experiments are discussed and presented with the goal of avoiding dosage group biases related to cage location. Considerations in selecting a cage design are first discussed in general terms. Specific designs are presented for use in experiments involving three, four, and five dose groups and with one, four, and five rodents per cage. Priorities for balancing treatment groups include horizontal position on shelf and shelf of rack, nearest neighbor balance, and male–female balance. It is proposed that these balance criteria be considered together with practical issues, such as the ability to accurately conform to a design and to determine a sensible and efficient design for each experiment. PMID:17539183

  12. Cage allocation designs for rodent carcinogenicity experiments.

    PubMed Central

    Herzberg, A M; Lagakos, S W

    1992-01-01

    Cage allocation designs for rodent carcinogenicity experiments are discussed and presented with the goal of avoiding dosage group biases related to cage location. Considerations in selecting a cage design are first discussed in general terms. Specific designs are presented for use in experiments involving three, four, and five dose groups and with one, four, and five rodents per cage. Priorities for balancing treatment groups include horizontal position on shelf and shelf of rack, nearest neighbor balance, and male-female balance. It is proposed that these balance criteria be considered together with practical issues, such as the ability to accurately conform to a design and to determine a sensible and efficient design for each experiment. PMID:1295494

  13. Leptospira interrogans in Rodents from Cape Verde.

    PubMed

    Plata-Luis, Josué; Foronda, Pilar; Martín-Alonso, Aaron; Feliu, Carlos; Alves, Joana; Gil, Horacio; Valladares, Basilio

    2016-11-01

    Leptospirosis is an important worldwide zoonotic disease that can infect both animals and humans. In most cases, leptospirosis is a nonspecific self-limiting illness, but some patients can develop a severe form with a high mortality. This study was carried out in Santiago Island, Cape Verde, in 2012-2013. A total of 62 wild rodents (Rattus rattus and Mus domesticus) were analyzed. The lipL32 gene, present only in pathogenic Leptospira spp., was amplified by PCR, and 16 samples were positive (25.8%). In both rodent species, Leptospira interrogans was identified. The results show the presence of pathogenic Leptospira in the three localities analyzed in Santiago. The presence of L. interrogans demonstrates a serious health risk for the population, since this species has been associated with the most severe form of leptospirosis, the Weil's disease in humans, a severe infection with jaundice, renal failure, and hemorrhage.

  14. Bats and Rodents Shape Mammalian Retroviral Phylogeny

    PubMed Central

    Cui, Jie; Tachedjian, Gilda; Wang, Lin-Fa

    2015-01-01

    Endogenous retroviruses (ERVs) represent past retroviral infections and accordingly can provide an ideal framework to infer virus-host interaction over their evolutionary history. In this study, we target high quality Pol sequences from 7,994 Class I and 8,119 Class II ERVs from 69 mammalian genomes and surprisingly find that retroviruses harbored by bats and rodents combined occupy the major phylogenetic diversity of both classes. By analyzing transmission patterns of 30 well-defined ERV clades, we corroborate the previously published observation that rodents are more competent as originators of mammalian retroviruses and reveal that bats are more capable of receiving retroviruses from non-bat mammalian origins. The powerful retroviral hosting ability of bats is further supported by a detailed analysis revealing that the novel bat gammaretrovirus, Rhinolophus ferrumequinum retrovirus, likely originated from tree shrews. Taken together, this study advances our understanding of host-shaped mammalian retroviral evolution in general. PMID:26548564

  15. Evidence for Novel Hepaciviruses in Rodents

    PubMed Central

    Drexler, Jan Felix; Corman, Victor Max; Müller, Marcel Alexander; Lukashev, Alexander N.; Gmyl, Anatoly; Coutard, Bruno; Adam, Alexander; Ritz, Daniel; Leijten, Lonneke M.; van Riel, Debby; Kallies, Rene; Klose, Stefan M.; Gloza-Rausch, Florian; Binger, Tabea; Annan, Augustina; Adu-Sarkodie, Yaw; Oppong, Samuel; Bourgarel, Mathieu; Rupp, Daniel; Hoffmann, Bernd; Schlegel, Mathias; Kümmerer, Beate M.; Krüger, Detlev H.; Schmidt-Chanasit, Jonas; Setién, Alvaro Aguilar; Cottontail, Veronika M.; Hemachudha, Thiravat; Wacharapluesadee, Supaporn; Osterrieder, Klaus; Bartenschlager, Ralf; Matthee, Sonja; Beer, Martin; Kuiken, Thijs; Reusken, Chantal; Leroy, Eric M.; Ulrich, Rainer G.; Drosten, Christian

    2013-01-01

    Hepatitis C virus (HCV) is among the most relevant causes of liver cirrhosis and hepatocellular carcinoma. Research is complicated by a lack of accessible small animal models. The systematic investigation of viruses of small mammals could guide efforts to establish such models, while providing insight into viral evolutionary biology. We have assembled the so-far largest collection of small-mammal samples from around the world, qualified to be screened for bloodborne viruses, including sera and organs from 4,770 rodents (41 species); and sera from 2,939 bats (51 species). Three highly divergent rodent hepacivirus clades were detected in 27 (1.8%) of 1,465 European bank voles (Myodes glareolus) and 10 (1.9%) of 518 South African four-striped mice (Rhabdomys pumilio). Bats showed anti-HCV immunoblot reactivities but no virus detection, although the genetic relatedness suggested by the serologic results should have enabled RNA detection using the broadly reactive PCR assays developed for this study. 210 horses and 858 cats and dogs were tested, yielding further horse-associated hepaciviruses but none in dogs or cats. The rodent viruses were equidistant to HCV, exceeding by far the diversity of HCV and the canine/equine hepaciviruses taken together. Five full genomes were sequenced, representing all viral lineages. Salient genome features and distance criteria supported classification of all viruses as hepaciviruses. Quantitative RT-PCR, RNA in-situ hybridisation, and histopathology suggested hepatic tropism with liver inflammation resembling hepatitis C. Recombinant serology for two distinct hepacivirus lineages in 97 bank voles identified seroprevalence rates of 8.3 and 12.4%, respectively. Antibodies in bank vole sera neither cross-reacted with HCV, nor the heterologous bank vole hepacivirus. Co-occurrence of RNA and antibodies was found in 3 of 57 PCR-positive bank vole sera (5.3%). Our data enable new hypotheses regarding HCV evolution and encourage efforts to

  16. Geometric Morphometrics of Rodent Sperm Head Shape

    PubMed Central

    Varea Sánchez, María; Bastir, Markus; Roldan, Eduardo R. S.

    2013-01-01

    Mammalian spermatozoa, particularly those of rodent species, are extremely complex cells and differ greatly in form and dimensions. Thus, characterization of sperm size and, particularly, sperm shape represents a major challenge. No consensus exists on a method to objectively assess size and shape of spermatozoa. In this study we apply the principles of geometric morphometrics to analyze rodent sperm head morphology and compare them with two traditional morphometry methods, that is, measurements of linear dimensions and dimensions-derived parameters calculated using formulae employed in sperm morphometry assessments. Our results show that geometric morphometrics clearly identifies shape differences among rodent spermatozoa. It is also capable of discriminating between size and shape and to analyze these two variables separately. Thus, it provides an accurate method to assess sperm head shape. Furthermore, it can identify which sperm morphology traits differ between species, such as the protrusion or retraction of the base of the head, the orientation and relative position of the site of flagellum insertion, the degree of curvature of the hook, and other distinct anatomical features and appendices. We envisage that the use of geometric morphometrics may have a major impact on future studies focused on the characterization of sperm head formation, diversity of sperm head shape among species (and underlying evolutionary forces), the effects of reprotoxicants on changes in cell shape, and phenotyping of genetically-modified individuals. PMID:24312234

  17. Rodents and risk in the Mekong Delta of Vietnam: seroprevalence of selected zoonotic viruses in rodents and humans.

    PubMed

    Van Cuong, Nguyen; Carrique-Mas, Juan; Vo Be, Hien; An, Nguyen Ngoc; Tue, Ngo Tri; Anh, Nguyet Lam; Anh, Pham Hong; Phuc, Nguyen The; Baker, Stephen; Voutilainen, Liina; Jääskeläinen, Anne; Huhtamo, Eili; Utriainen, Mira; Sironen, Tarja; Vaheri, Antti; Henttonen, Heikki; Vapalahti, Olli; Chaval, Yannick; Morand, Serge; Bryant, Juliet E

    2015-01-01

    In the Mekong Delta in southern Vietnam, rats are commonly traded in wet markets and sold live for food consumption. We investigated seroprevalence to selected groups of rodent-borne viruses among human populations with high levels of animal exposure and among co-located rodent populations. The indirect fluorescence antibody test (IFAT) was used to determine seropositivity to representative reference strains of hantaviruses (Dobrava virus [DOBV], Seoul virus [SEOV]), cowpox virus, arenaviruses (lymphocytic choriomeningitis virus [LCMV]), flaviviruses (tick-borne encephalitis virus [TBEV]), and rodent parechoviruses (Ljungan virus), using sera from 245 humans living in Dong Thap Province and 275 rodents representing the five common rodent species sold in wet markets and present in peridomestic and farm settings. Combined seropositivity to DOBV and SEOV among the rodents and humans was 6.9% (19/275) and 3.7% (9/245), respectively; 1.1% (3/275) and 4.5% (11/245) to cowpox virus; 5.4% (15/275) and 47.3% (116/245) for TBEV; and exposure to Ljungan virus was 18.8% (46/245) in humans, but 0% in rodents. Very little seroreactivity was observed to LCMV in either rodents (1/275, 0.4%) or humans (2/245, 0.8%). Molecular screening of rodent liver tissues using consensus primers for flaviviruses did not yield any amplicons, whereas molecular screening of rodent lung tissues for hantavirus yielded one hantavirus sequence (SEOV). In summary, these results indicate low to moderate levels of endemic hantavirus circulation, possible circulation of a flavivirus in rodent reservoirs, and the first available data on human exposures to parechoviruses in Vietnam. Although the current evidence suggests only limited exposure of humans to known rodent-borne diseases, further research is warranted to assess public health implications of the rodent trade.

  18. Leptospira and Rodents in Cambodia: Environmental Determinants of Infection

    PubMed Central

    Ivanova, Svilena; Herbreteau, Vincent; Blasdell, Kim; Chaval, Yannick; Buchy, Philippe; Guillard, Bertrand; Morand, Serge

    2012-01-01

    We investigated infection of rodents and shrews by Leptospira spp. in two localities of Cambodia (Veal Renh, Kaev Seima) and in four types of habitat (forests, non-flooded lands, lowland rain-fed paddy fields, houses) during the wet and the dry seasons. Habitat preference was common, and rodent and shrew species were found only in houses or in rain-fed paddy fields or in forests. Among 649 small mammals trapped belonging to 12 rodent species and 1 shrew species, 71 of 642 animals tested were carriers of Leptospira according to the 16S ribosomal RNA marker used. Rodent infection was higher in low-slope locations, corresponding to rain-fed paddy fields, especially in the rainy season and in Kaev Seima. Rodents (Rattus exulans) and shrews (Suncus murinus) inhabiting households showed significantly low levels of infections, whereas rodents living in and near to forests (shrubby wasteland, orchards) showed high levels of infection. PMID:22665613

  19. Bartonella infection in rodents and their flea ectoparasites: an overview.

    PubMed

    Gutiérrez, Ricardo; Krasnov, Boris; Morick, Danny; Gottlieb, Yuval; Khokhlova, Irina S; Harrus, Shimon

    2015-01-01

    Epidemiological studies worldwide have reported a high prevalence and a great diversity of Bartonella species, both in rodents and their flea parasites. The interaction among Bartonella, wild rodents, and fleas reflects a high degree of adaptation among these organisms. Vertical and horizontal efficient Bartonella transmission pathways within flea communities and from fleas to rodents have been documented in competence studies, suggesting that fleas are key players in the transmission of Bartonella to rodents. Exploration of the ecological traits of rodents and their fleas may shed light on the mechanisms used by bartonellae to become established in these organisms. The present review explores the interrelations within the Bartonella-rodent-flea system. The role of the latter two components is emphasized.

  20. Retinal image quality in the rodent eye.

    PubMed

    Artal, P; Herreros de Tejada, P; Muñoz Tedó, C; Green, D G

    1998-01-01

    Many rodents do not see well. For a target to be resolved by a rat or a mouse, it must subtend a visual angle of a degree or more. It is commonly assumed that this poor spatial resolving capacity is due to neural rather than optical limitations, but the quality of the retinal image has not been well characterized in these animals. We have modified a double-pass apparatus, initially designed for the human eye, so it could be used with rodents to measure the modulation transfer function (MTF) of the eye's optics. That is, the double-pass retinal image of a monochromatic (lambda = 632.8 nm) point source was digitized with a CCD camera. From these double-pass measurements, the single-pass MTF was computed under a variety of conditions of focus and with different pupil sizes. Even with the eye in best focus, the image quality in both rats and mice is exceedingly poor. With a 1-mm pupil, for example, the MTF in the rat had an upper limit of about 2.5 cycles/deg, rather than the 28 cycles/deg one would obtain if the eye were a diffraction-limited system. These images are about 10 times worse than the comparable retinal images in the human eye. Using our measurements of the optics and the published behavioral and electrophysiological contrast sensitivity functions (CSFs) of rats, we have calculated the CSF that the rat would have if it had perfect rather than poor optics. We find, interestingly, that diffraction-limited optics would produce only slight improvement overall. That is, in spite of retinal images which are of very low quality, the upper limit of visual resolution in rodents is neurally determined. Rats and mice seem to have eyes in which the optics and retina/brain are well matched.

  1. Euthanasia using gaseous agents in laboratory rodents.

    PubMed

    Valentim, A M; Guedes, S R; Pereira, A M; Antunes, L M

    2016-08-01

    Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously. Nevertheless, its aversive potential has been criticized in terms of animal welfare. The data available regarding the use of carbon dioxide (CO2), inhaled anaesthetics (such as isoflurane, sevoflurane, halothane and enflurane), as well as carbon monoxide and inert gases are discussed throughout this review. Euthanasia of fetuses and neonates is also addressed. A table listing currently available information to ease access to data regarding euthanasia techniques using gaseous agents in laboratory rodents was compiled. Regarding better animal welfare, there is currently insufficient evidence to advocate banning or replacing CO2 in the euthanasia of rodents; however, there are hints that alternative gases are more humane. The exposure to a volatile anaesthetic gas before loss of consciousness has been proposed by some scientific studies to minimize distress; however, the impact of such a measure is not clear. Areas of inconsistency within the euthanasia literature have been highlighted recently and stem from insufficient knowledge, especially regarding the advantages of the administration of isoflurane or sevoflurane over CO2, or other methods, before loss of consciousness. Alternative methods to minimize distress may include the development of techniques aimed at inducing death in the home cage of animals. Scientific outcomes have to be considered before choosing the most suitable euthanasia method to obtain the best results and accomplish the 3Rs (replacement, reduction and refinement).

  2. Klebsiella oxytoca: opportunistic infections in laboratory rodents.

    PubMed

    Bleich, Andre; Kirsch, Petra; Sahly, Hany; Fahey, Jim; Smoczek, Anna; Hedrich, Hans-Jürgen; Sundberg, John P

    2008-07-01

    Opportunistic pathogens have become increasingly relevant as the causative agents of clinical disease and pathological lesions in laboratory animals. This study was conducted to evaluate the role of Klebsiella oxytoca as an opportunistic pathogen in laboratory rodents. Therefore, K. oxytoca-induced lesions were studied from 2004 to early 2006 in naturally infected rodent colonies maintained at The Jackson Laboratory (TJL), Bar Harbor, USA, the Animal Research Centre (Tierforschungszentrum, TFZ) of the University of Ulm, Germany and the Central Animal Facility (ZTM) of the Hannover Medical School, Germany. K. oxytoca infections were observed in substrains of C3H/HeJ mice, which carry the Tlr4(Lps-d) allele; in LEW.1AR1-iddm rats, the latter being prone to diabetes mellitus; in immunodeficient NMRI-Foxn1(nu) mice; and in mole voles, Ellobius lutescens. The main lesions observed were severe suppurative otitis media, urogenital tract infections and pneumonia. Bacteriological examination revealed K. oxytoca as monocultures in all cases. Clonality analysis performed on strains isolated at the ZTM and TFZ (serotyping, pulse field gel electrophoresis [PFGE], enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction, sequencing of 16S rRNA and rpoB genes) revealed that the majority of bacteria belonged to two clones, one in each facility, expressing the capsule type K55 (ZTM) or K72 (TFZ). Two strains, one isolated at the ZTM and one at the TFZ, showed different PFGE and ERIC pattern than all other isolates and both expressed capsule type K35. In conclusion, K. oxytoca is an opportunistic pathogen capable of inducing pathological lesions in different rodent species.

  3. Control of Domestic Rats & Mice, Training Guide--Rodent Control Series.

    ERIC Educational Resources Information Center

    Bjornson, Bayard F.; And Others

    As one booklet in a series on rodent control, this training guide has been developed to assist administrators, rodent-control operators, and others responsible for rodent-control operations in the training of employees in this field. Topics covered include rodents and human welfare, description and habits of domestic rats and mice, rodent-borne…

  4. Rodent models of treatment-resistant depression

    PubMed Central

    Caldarone, Barbara J.; Zachariou, Venetia; King, Sarah L

    2015-01-01

    Major depression is a prevalent and debilitating disorder and a substantial proportion of patients fail to reach remission following standard antidepressant pharmacological treatment. Limited efficacy with currently available antidepressant drugs highlights the need to develop more effective medications for treatment resistant patients and emphasizes the importance of developing better preclinical models that focus on treatment resistant populations. This review discusses methods to adapt and refine rodent behavioral models that are predictive of antidepressant efficacy to identify populations that show reduced responsiveness or are resistant to traditional antidepressants. Methods include separating antidepressant responders from non-responders, administering treatments that render animals resistant to traditional pharmacological treatments, and identifying genetic models that show antidepressant resistance. This review also examines pharmacological and non-pharmacological treatments regimes that have been effective in refractory patients and how some of these approaches have been used to validate animal models of treatment-resistant depression. The goals in developing rodent models of treatment-resistant depression are to understand the neurobiological mechanisms involved in antidepressant resistance and to develop valid models to test novel therapies that would be effective in patients that do not respond to traditional monoaminergic antidepressants. PMID:25460020

  5. Rodent Models of Amyotrophic Lateral Sclerosis.

    PubMed

    Philips, Thomas; Rothstein, Jeffrey D

    2015-06-01

    Amyotrophic Lateral Sclerosis (ALS) is a motor neuron disease affecting upper and lower motor neurons in the central nervous system. Patients with ALS develop extensive muscle wasting and atrophy leading to paralysis and death 3 to 5 years after disease onset. The condition may be familial (fALS 10%) or sporadic ALS (sALS, 90%). The large majority of fALS cases are due to genetic mutations in the Superoxide dismutase 1 gene (SOD1, 15% of fALS) and repeat nucleotide expansions in the gene encoding C9ORF72 (∼ 40% to 50% of fALS and ∼ 10% of sALS). Studies suggest that ALS is mediated through aberrant protein homeostasis (i.e., ER stress and autophagy) and/or changes in RNA processing (as in all non-SOD1-mediated ALS). In all of these cases, animal models suggest that the disorder is mediated non-cell autonomously, i.e., not only motor neurons are involved, but glial cells including microglia, astrocytes, and oligodendrocytes, and other neuronal subpopulations are also implicated in the pathogenesis. Provided in this unit is a review of ALS rodent models, including discussion of their relative advantages and disadvantages. Emphasis is placed on correlating the model phenotype with the human condition and the utility of the model for defining the disease process. Information is also presented on RNA processing studies in ALS research, with particular emphasis on the newest ALS rodent models.

  6. Hunting, Food Preparation, and Consumption of Rodents in Lao PDR.

    PubMed

    Suwannarong, Kanokwan; Chapman, Robert S; Lantican, Cecile; Michaelides, Tula; Zimicki, Susan

    2015-01-01

    A cross-sectional study was conducted in 29 villages of Khamkeuth District in Bolikhamxay Province in the Lao PDR during March to May 2013. The study aimed to determine the characteristics associated with rodent consumption and related behaviors among different ethnic groups, ages, and genders. Five-hundred-eighty-four (584) males and females from 18-50 years of age participated in this study. Half of them were Hmong (292, 50%) while 152 respondents were Lao-Tai (26%) or other ethnic groups (140, 24%). Most of the respondents (79.5%) had farming as their main occupation. Prevalences of the studied outcomes were high: 39.9 for hunting or capturing rodents in the previous year, 77.7% for preparing rodents as food, and 86.3% for rodent consumption. Multivariable logistic regression analysis showed that likelihood of these types of rodent contact was more consistently associated with behavioral factors (gathering things from the forest and elsewhere, cultivation-related activities, and taking measures to prevent rodent-borne disease) than with socio-demographic, environmental, or cultural factors. The strongest associations were observed for gathering things; these associations were consistently positive and statistically significant. Although this study did not directly assess rodent-borne zoonosis risk, we believe that study findings raise concern that such risk may be substantial in the study area and other similar areas. Further epidemiological studies on the association between rodent-borne disease infection and rodent hunting, preparation for food, and consumption are recommended. Moreover, further studies are needed on the association between these potential exposure factors (i.e., rodent hunting, preparation for food, and consumption) and rodent-borne infections, especially among ethnic groups like the Hmong in Lao PDR and those in neighboring countries with similar socio-demographic, environmental, behavioral and cultural contexts.

  7. Hunting, Food Preparation, and Consumption of Rodents in Lao PDR

    PubMed Central

    Suwannarong, Kanokwan; Chapman, Robert S.; Lantican, Cecile; Michaelides, Tula; Zimicki, Susan

    2015-01-01

    A cross-sectional study was conducted in 29 villages of Khamkeuth District in Bolikhamxay Province in the Lao PDR during March to May 2013. The study aimed to determine the characteristics associated with rodent consumption and related behaviors among different ethnic groups, ages, and genders. Five-hundred-eighty-four (584) males and females from 18-50 years of age participated in this study. Half of them were Hmong (292, 50%) while 152 respondents were Lao-Tai (26%) or other ethnic groups (140, 24%). Most of the respondents (79.5%) had farming as their main occupation. Prevalences of the studied outcomes were high: 39.9 for hunting or capturing rodents in the previous year, 77.7% for preparing rodents as food, and 86.3% for rodent consumption. Multivariable logistic regression analysis showed that likelihood of these types of rodent contact was more consistently associated with behavioral factors (gathering things from the forest and elsewhere, cultivation-related activities, and taking measures to prevent rodent-borne disease) than with socio-demographic, environmental, or cultural factors. The strongest associations were observed for gathering things; these associations were consistently positive and statistically significant. Although this study did not directly assess rodent-borne zoonosis risk, we believe that study findings raise concern that such risk may be substantial in the study area and other similar areas. Further epidemiological studies on the association between rodent-borne disease infection and rodent hunting, preparation for food, and consumption are recommended. Moreover, further studies are needed on the association between these potential exposure factors (i.e., rodent hunting, preparation for food, and consumption) and rodent-borne infections, especially among ethnic groups like the Hmong in Lao PDR and those in neighboring countries with similar socio-demographic, environmental, behavioral and cultural contexts. PMID:26196134

  8. PREDICTIVE SIMULATION MODELING FOR ANTIANDROGEN IMPACTS ON RODENT PROSTATE

    EPA Science Inventory

    Predictive simulation modeling for antiandrogen impacts on rodent prostate
    HA Barton1, RW Setzer1, LK Potter1,2
    1US EPA, ORD, NHEERL, ETD, PKB, Research Triangle Park, NC and 2Curriculum in Toxicology, UNC, Chapel Hill, NC

    Changes in rodent prostate weight and functi...

  9. Vitamin K Contents of Rodent Diets: A Review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adequate nutrient intake is critical in the maintenance of normal physiological activity of rodents in biomedical studies. Vitamin K is an essential nutrient in rodent diets and functions as a cofactor for the y-carboxylation of certain proteins involved in blood coagulation and bone metabolism. Dif...

  10. Visual Landmarks Facilitate Rodent Spatial Navigation in Virtual Reality Environments

    ERIC Educational Resources Information Center

    Youngstrom, Isaac A.; Strowbridge, Ben W.

    2012-01-01

    Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain…

  11. Lurking in the Shadows: Emerging Rodent Infectious Diseases

    PubMed Central

    Besselsen, David G.; Franklin, Craig L.; Livingston, Robert S.; Riley, Lela K.

    2013-01-01

    Rodent parvoviruses, Helicobacter spp., murine norovirus, and several other previously unknown infectious agents have “emerged” in laboratory rodents relatively recently. These agents have been discovered serendipitously or through active investigation of atypical serology results, cell culture contamination, unexpected histopathology, or previously unrecognized clinical disease syndromes. The potential research impact of these agents is not fully known. Infected rodents have demonstrated immunomodulation, tumor suppression, clinical disease (particularly in immunodeficient rodents), and histopathology. Perturbations of organismal and cellular physiology also likely occur. These agents posed unique challenges to laboratory animal resource programs once discovered; it was necessary to develop specific diagnostic assays and an understanding of their epidemiology and transmission routes before attempting eradication, and then evaluate eradication methods for efficacy. Even then management approaches varied significantly, from apathy to total exclusion, and such inconsistency has hindered the sharing and transfer of rodents among institutions, particularly for genetically modified rodent models that may not be readily available. As additional infectious agents are discovered in laboratory rodents in coming years, much of what researchers have learned from experiences with the recently identified pathogens will be applicable. This article provides an overview of the discovery, detection, and research impact of infectious agents recently identified in laboratory rodents. We also discuss emerging syndromes for which there is a suspected infectious etiology, and the unique challenges of managing newly emerging infectious agents. PMID:18506061

  12. Bartonella Infection in Rodents and Their Flea Ectoparasites: An Overview

    PubMed Central

    Gutiérrez, Ricardo; Krasnov, Boris; Morick, Danny; Gottlieb, Yuval; Khokhlova, Irina S.

    2015-01-01

    Abstract Epidemiological studies worldwide have reported a high prevalence and a great diversity of Bartonella species, both in rodents and their flea parasites. The interaction among Bartonella, wild rodents, and fleas reflects a high degree of adaptation among these organisms. Vertical and horizontal efficient Bartonella transmission pathways within flea communities and from fleas to rodents have been documented in competence studies, suggesting that fleas are key players in the transmission of Bartonella to rodents. Exploration of the ecological traits of rodents and their fleas may shed light on the mechanisms used by bartonellae to become established in these organisms. The present review explores the interrelations within the Bartonella–rodent–flea system. The role of the latter two components is emphasized. PMID:25629778

  13. Scatter-hoarding rodents prefer slightly astringent food.

    PubMed

    Wang, Bo; Chen, Jin

    2011-01-01

    The mutualistic interaction between scatter-hoarding rodents and their seed plants is highly complex yet poorly understood. Plants may benefit from the seed dispersal behavior of rodents, as long as seed consumption is minimized. In parallel, rodents may maximize foraging efficiency and cache high-quality resources for future consumption. Defensive compounds, such as tannins, are thought to be a major mechanism for plant control over rodent behavior. However, previous studies, using naturally occurring seeds, have not provided conclusive evidence supporting this hypothesis. Here, we test the importance of tannin concentrations on the scatter-hoarding behavior of rodents by using an artificial seed system. We combined feeding trials and field observations to examine the overall impact of seed tannin concentrations on rodent behavior and health. We found that rodents favored seeds with an intermediate amount of tannin (~5%) in the field. Meanwhile, in rodents that were fed a diet with different tannin content, only diets with high tannin content (25%, 15%, and 10%) caused a significant negative influence on rodent survival and health. Significant differences were not found among treatments with tannin levels of 0-5%. In contrast to many existing studies, our results clearly demonstrate that scatter-hoarding rodents prefer slightly 'astringent' food. In the co-evolutionary arms race between plants and animals, our results suggest that while tannins may play a significant role in reducing general predation levels by the faunal community, they have no precise control over the behavior of their mutualistic partner. Instead, the two partners appear to have reached an evolutionary point where both parties receive adequate benefits, with the year-to-year outcome being dependent on a wide range of factors beyond the control of either partner.

  14. Epidemiology of Leptospira Transmitted by Rodents in Southeast Asia

    PubMed Central

    Mielcarek, Mathilde; Tatard, Caroline; Chaval, Yannick; Suputtamongkol, Yupin; Buchy, Philippe; Jittapalapong, Sathaporn; Herbreteau, Vincent; Morand, Serge

    2014-01-01

    Background Leptospirosis is the most common bacterial zoonoses and has been identified as an important emerging global public health problem in Southeast Asia. Rodents are important reservoirs for human leptospirosis, but epidemiological data is lacking. Methodology/Principal Findings We sampled rodents living in different habitats from seven localities distributed across Southeast Asia (Thailand, Lao PDR and Cambodia), between 2009 to 2010. Human isolates were also obtained from localities close to where rodents were sampled. The prevalence of Leptospira infection was assessed by real-time PCR using DNA extracted from rodent kidneys, targeting the lipL32 gene. Sequencing rrs and secY genes, and Multi Locus Variable-number Tandem Repeat (VNTR) analyses were performed on DNA extracted from rat kidneys for Leptospira isolates molecular typing. Four species were detected in rodents, L. borgpetersenii (56% of positive samples), L. interrogans (36%), L. kirschneri (3%) and L. weilli (2%), which were identical to human isolates. Mean prevalence in rodents was approximately 7%, and largely varied across localities and habitats, but not between rodent species. The two most abundant Leptospira species displayed different habitat requirements: L. interrogans was linked to humid habitats (rice fields and forests) while L. borgpetersenii was abundant in both humid and dry habitats (non-floodable lands). Conclusion/Significance L. interrogans and L. borgpetersenii species are widely distributed amongst rodent populations, and strain typing confirmed rodents as reservoirs for human leptospirosis. Differences in habitat requirements for L. interrogans and L. borgpetersenii supported differential transmission modes. In Southeast Asia, human infection risk is not only restricted to activities taking place in wetlands and rice fields as is commonly accepted, but should also include tasks such as forestry work, as well as the hunting and preparation of rodents for consumption, which

  15. Nutrition and energetics in rodent longevity research.

    PubMed

    Gibbs, Victoria K; Smith, Daniel L

    2016-12-15

    The impact of calorie amount on aging has been extensively described; however, variation over time and among laboratories in animal diet, housing condition, and strains complicates discerning the true influence of calories (energy) versus nutrients on lifespan. Within the dietary restriction field, single macronutrient manipulations have historically been researched as a means to reduce calories while maintaining adequate levels of essential nutrients. Recent reports of nutritional geometry, including rodent models, highlight the impact macronutrients have on whole organismal aging outcomes. However, other environmental factors (e.g., ambient temperature) may alter nutrient preferences and requirements revealing context specific outcomes. Herein we highlight factors that influence the energetic and nutrient demands of organisms which oftentimes have underappreciated impacts on clarifying interventional effects on health and longevity in aging studies and subsequent translation to improve the human condition.

  16. Oxytocin-dependent consolation behavior in rodents

    PubMed Central

    Burkett, J. P.; Andari, E.; Johnson, Z. V.; Curry, D. C.; de Waal, F. B. M.; Young, L. J.

    2016-01-01

    Consolation behavior toward distressed others is common in humans and great apes, yet our ability to explore the biological mechanisms underlying this behavior is limited by its apparent absence in laboratory animals. Here, we provide empirical evidence that a rodent species, the highly social and monogamous prairie vole (Microtus ochrogaster), greatly increases partner-directed grooming toward familiar conspecifics (but not strangers) that have experienced an unobserved stressor, providing social buffering. Prairie voles also match the fear response, anxiety-related behaviors, and corticosterone increase of the stressed cagemate, suggesting an empathy mechanism. Exposure to the stressed cagemate increases activity in the anterior cingulate cortex, and oxytocin receptor antagonist infused into this region abolishes the partner-directed response, showing conserved neural mechanisms between prairie vole and human. PMID:26798013

  17. Intraoperative cerebral blood flow imaging of rodents

    NASA Astrophysics Data System (ADS)

    Li, Hangdao; Li, Yao; Yuan, Lu; Wu, Caihong; Lu, Hongyang; Tong, Shanbao

    2014-09-01

    Intraoperative monitoring of cerebral blood flow (CBF) is of interest to neuroscience researchers, which offers the assessment of hemodynamic responses throughout the process of neurosurgery and provides an early biomarker for surgical guidance. However, intraoperative CBF imaging has been challenging due to animal's motion and position change during the surgery. In this paper, we presented a design of an operation bench integrated with laser speckle contrast imager which enables monitoring of the CBF intraoperatively. With a specially designed stereotaxic frame and imager, we were able to monitor the CBF changes in both hemispheres during the rodent surgery. The rotatable design of the operation plate and implementation of online image registration allow the technician to move the animal without disturbing the CBF imaging during surgery. The performance of the system was tested by middle cerebral artery occlusion model of rats.

  18. In vivo OCT microangiography of rodent iris.

    PubMed

    Choi, Woo June; Zhi, Zhongwei; Wang, Ruikang K

    2014-04-15

    We report on the functional optical coherence tomography (OCT) imaging of iris tissue morphology and microcirculation in living small animals. Anterior segments of healthy mouse and rat eyes are imaged with high-speed spectral domain OCT (SD-OCT) utilizing ultrahigh sensitive optical microangiography (UHS-OMAG) imaging protocol. 3D iris microvasculature is produced by the use of an algorithm that calculates absolute differences between the amplitudes of the OCT interframes. We demonstrate that the UHS-OMAG is capable of delineating iris microvascular beds in the mouse and rat with capillary-level resolution. Furthermore, the fast imaging speed enables dynamic imaging of iris micro-vascular response during drug-induced pupil dilation. We believe that this OCT angiographic approach has a great potential for in situ and in vivo monitoring of the microcirculation within iris tissue beds in rodent disease models that have microvascular involvement.

  19. Domestic Rodent Control Training Manual: A Training Aid for the Rodent Control Category for Certification of Pesticide Applicators.

    ERIC Educational Resources Information Center

    Childress, William R., Jr.; And Others

    This training manual, designed for training applicants who wish to obtain certification in pesticide application relative to rodent control, covers the following topics: economic factors, public health factors, biological characteristics of domestic rodents, rat and mouse signs, trapping, repellents, poisons, baits, poisoned water, dumps, sewers,…

  20. Brain acetylcholinesterase activity recovery following acute methyl parathion intoxication in two feral rodent species: comparison to laboratory rodents

    SciTech Connect

    Roberts, D.K.; Silvey, N.J.; Bailey, E.M. Jr.

    1988-07-01

    Widespread use of organophosphorus insecticides (OPs) has produced both acute and chronic intoxication among nontarget organisms. Most such studies have included fish and birds as opposed to mammals. However, numerous OP toxicity studies have been conducted on laboratory rodents creating a temptation to apply this data to feral rodents. Chronic OP exposure has been reported to produce cholinergic adaptation which in turn lowers mortality rates following a subsequent acute anticholinesterase exposure. The relevance that these laboratory rodent studies have on feral rodents is subject to debate. Field studies involving OP exposure among nontarget feral mammals have produced contradictory results. Increased mortality as a result of repeated OP application has been reported. This observation may be of considerable importance to nontarget feral rodent populations due to the repetitive nature of OP application protocols. The ability of feral rodents to recover brain AChE activity (BAA) between OP application intervals undoubtedly promotes their survival. This study investigated and compared BAA recovery following acute oral methyl parathion intoxication among 2 feral rodent species and among 2 common laboratory rodent species.

  1. A Curated Database of Rodent Uterotrophic Bioactivity

    PubMed Central

    Kleinstreuer, Nicole C.; Ceger, Patricia C.; Allen, David G.; Strickland, Judy; Chang, Xiaoqing; Hamm, Jonathan T.; Casey, Warren M.

    2015-01-01

    Background: Novel in vitro methods are being developed to identify chemicals that may interfere with estrogen receptor (ER) signaling, but the results are difficult to put into biological context because of reliance on reference chemicals established using results from other in vitro assays and because of the lack of high-quality in vivo reference data. The Organisation for Economic Co-operation and Development (OECD)-validated rodent uterotrophic bioassay is considered the “gold standard” for identifying potential ER agonists. Objectives: We performed a comprehensive literature review to identify and evaluate data from uterotrophic studies and to analyze study variability. Methods: We reviewed 670 articles with results from 2,615 uterotrophic bioassays using 235 unique chemicals. Study descriptors, such as species/strain, route of administration, dosing regimen, lowest effect level, and test outcome, were captured in a database of uterotrophic results. Studies were assessed for adherence to six criteria that were based on uterotrophic regulatory test guidelines. Studies meeting all six criteria (458 bioassays on 118 unique chemicals) were considered guideline-like (GL) and were subsequently analyzed. Results: The immature rat model was used for 76% of the GL studies. Active outcomes were more prevalent across rat models (74% active) than across mouse models (36% active). Of the 70 chemicals with at least two GL studies, 18 (26%) had discordant outcomes and were classified as both active and inactive. Many discordant results were attributable to differences in study design (e.g., injection vs. oral dosing). Conclusions: This uterotrophic database provides a valuable resource for understanding in vivo outcome variability and for evaluating the performance of in vitro assays that measure estrogenic activity. Citation: Kleinstreuer NC, Ceger PC, Allen DG, Strickland J, Chang X, Hamm JT, Casey WM. 2016. A curated database of rodent uterotrophic bioactivity. Environ

  2. Automatic cortical thickness analysis on rodent brain

    NASA Astrophysics Data System (ADS)

    Lee, Joohwi; Ehlers, Cindy; Crews, Fulton; Niethammer, Marc; Budin, Francois; Paniagua, Beatriz; Sulik, Kathy; Johns, Josephine; Styner, Martin; Oguz, Ipek

    2011-03-01

    Localized difference in the cortex is one of the most useful morphometric traits in human and animal brain studies. There are many tools and methods already developed to automatically measure and analyze cortical thickness for the human brain. However, these tools cannot be directly applied to rodent brains due to the different scales; even adult rodent brains are 50 to 100 times smaller than humans. This paper describes an algorithm for automatically measuring the cortical thickness of mouse and rat brains. The algorithm consists of three steps: segmentation, thickness measurement, and statistical analysis among experimental groups. The segmentation step provides the neocortex separation from other brain structures and thus is a preprocessing step for the thickness measurement. In the thickness measurement step, the thickness is computed by solving a Laplacian PDE and a transport equation. The Laplacian PDE first creates streamlines as an analogy of cortical columns; the transport equation computes the length of the streamlines. The result is stored as a thickness map over the neocortex surface. For the statistical analysis, it is important to sample thickness at corresponding points. This is achieved by the particle correspondence algorithm which minimizes entropy between dynamically moving sample points called particles. Since the computational cost of the correspondence algorithm may limit the number of corresponding points, we use thin-plate spline based interpolation to increase the number of corresponding sample points. As a driving application, we measured the thickness difference to assess the effects of adolescent intermittent ethanol exposure that persist into adulthood and performed t-test between the control and exposed rat groups. We found significantly differing regions in both hemispheres.

  3. Rodent laparoscopy: refinement for rodent drug studies and model development, and monitoring of neoplastic, inflammatory and metabolic diseases.

    PubMed

    Baran, Szczepan W; Perret-Gentil, Marcel I; Johnson, Elizabeth J; Miedel, Emily L; Kehler, James

    2011-10-01

    The refinement of surgical techniques represents a key opportunity to improve the welfare of laboratory rodents, while meeting legal and ethical obligations. Current methods used for monitoring intra-abdominal disease progression in rodents usually involve euthanasia at various time-points for end of study, one-time individual tissue collections. Most rodent organ tumour models are developed by the introduction of tumour cells via laparotomy or via ultrasound-guided indirect visualization. Ischaemic rodent models are often generated using laparotomies. This approach requires a high number of rodents, and in some instances introduces high degrees of morbidity and mortality, thereby increasing study variability and expense. Most importantly, most laparotomies do not promote the highest level of rodent welfare. Recent improvements in laparoscopic equipment and techniques have enabled the adaptation of laparoscopy for rodent procedures. Laparoscopy, which is considered the gold standard for many human abdominal procedures, allows for serial biopsy collections from the same animal, results in decreased pain and tissue trauma as well as quicker postsurgical recovery, and preserves immune function in comparison to the same procedures performed by laparotomy. Laparoscopy improves rodent welfare, decreases inter-animal variability, thereby reducing the number of required animals, allows for the replacement of larger species, decreases expense and improves data yield. This review article compares rodent laparotomy and laparoscopic surgical methods, and describes the utilization of laparoscopy for the development of cancer models and assessment of disease progression to improve data collection and animal welfare. In addition, currently available rodent laparoscopic equipment and instrumentation are presented.

  4. Interaction between acari ectoparasites and rodents in Suez Governorate, Egypt.

    PubMed

    Younis, T A; Fayad, M E; el Hariry, M A; Morsy, T A

    1995-08-01

    From the medical point of view, the relation between man and rodents comes in the priority. Some rodent populations are wild but others are commensal and live in close association with man. They steal his food and conveying many zoonotic diseases. Their arthropod ectoparasites play an important role in conveying or transmitting these zoonotic diseases. Several disorders and diseases of man are tick borne relapsing fever, Rocky mountain spotted fever, Lyme disease, and many others. Besides numerous species of mites occasionally infest man. They transmit several diseases as Rickettsia tsutsugamushi fever, epidemic haemorrhagic fever, and they cause severe allergic reaction. The results obtained are summarized in the following (1) Six species and subspecies of rodents were detected. In a descending order of abundance, they were (a) Rattus norvegicus, (b) Rattus rattus alexandrinus (c) Rattus rattus frugivorous (d) Acomys cahirinus (e) Gerbillus gerbillus asyutensis (f) Mus m. praetextus. (2) The most common rodent was R. norvegicus and the least common was M. musculus. (3) The collected ticks and mites were 2 genera of tick larvae; Rhipicephalus species and Hyalomma species. The collected mites were Ornithonyssus bacoti and Laelaps nuttali. (4) Most of the tick larvae were collected from wild rodents; Gerbillus g. asyutensis. (5) Most of the mites were collected from commensal rodents particularly R. norvegicus. Descriptive morphology and illustrations were given to the collected rodents and their acari ectoparasites.

  5. Identification of evolutionary hotspots in the rodent genomes.

    PubMed

    Yap, Von Bing; Pachter, Lior

    2004-04-01

    We describe a whole-genome comparative analysis of the human, mouse, and rat genomes to describe the average substitution patterns of four genomic regions: ancient repeats, rodent-specific DNA, exons, and conserved (coding and noncoding) regions, and to identify rodent evolutionary hotspots. In all types of regions, except the rodent-specific DNA, the rat branch is slightly longer than the mouse branch. Moreover, the mouse-rat distance is longer in the rodent-specific DNA than in the ancient repeats. Analysis of individual conserved regions with different substitution models yielded the conclusion that the Jukes-Cantor model is inadequate, and the Hasegawa-Kishino-Yano model is almost as good as the REV model. Using human as an outgroup, we identified 5055 evolutionary hotspots, which are highly conserved subalignment blocks (each consisting of at least 100 aligned sites and a small fraction of gaps) with a large and statistically significant difference in the branch lengths of the rodent species. The cutoffs used to identify the hotspots are partially based on estimates of the average rates of substitution. The fractions of hotspots overlapping with the rodent RefSeq genes, RefSeq exons, and ESTs are all higher than expected. Still, more than half of the hotspots lie in noncoding regions of the mouse genome. We believe that the hotspots represent biologically interesting regions in the rodent genomes.

  6. Data quality in predictive toxicology: reproducibility of rodent carcinogenicity experiments.

    PubMed Central

    Gottmann, E; Kramer, S; Pfahringer, B; Helma, C

    2001-01-01

    We compared 121 replicate rodent carcinogenicity assays from the two parts (National Cancer Institute/National Toxicology Program and literature) of the Carcinogenic Potency Database (CPDB) to estimate the reliability of these experiments. We estimated a concordance of 57% between the overall rodent carcinogenicity classifications from both sources. This value did not improve substantially when additional biologic information (species, sex, strain, target organs) was considered. These results indicate that rodent carcinogenicity assays are much less reproducible than previously expected, an effect that should be considered in the development of structure-activity relationship models and the risk assessment process. PMID:11401763

  7. Active vibrissal sensing in rodents and marsupials

    PubMed Central

    Mitchinson, Ben; Grant, Robyn A.; Arkley, Kendra; Rankov, Vladan; Perkon, Igor; Prescott, Tony J.

    2011-01-01

    In rats, the long facial whiskers (mystacial macrovibrissae) are repetitively and rapidly swept back and forth during exploration in a behaviour known as ‘whisking’. In this paper, we summarize previous evidence from rats, and present new data for rat, mouse and the marsupial grey short-tailed opossum (Monodelphis domestica) showing that whisking in all three species is actively controlled both with respect to movement of the animal's body and relative to environmental structure. Using automatic whisker tracking, and Fourier analysis, we first show that the whisking motion of the mystacial vibrissae, in the horizontal plane, can be approximated as a blend of two sinusoids at the fundamental frequency (mean 8.5, 11.3 and 7.3 Hz in rat, mouse and opossum, respectively) and its second harmonic. The oscillation at the second harmonic is particularly strong in mouse (around 22 Hz) consistent with previous reports of fast whisking in that species. In all three species, we found evidence of asymmetric whisking during head turning and following unilateral object contacts consistent with active control of whisker movement. We propose that the presence of active vibrissal touch in both rodents and marsupials suggests that this behavioural capacity emerged at an early stage in the evolution of therian mammals. PMID:21969685

  8. Pediatric Rodent Models of Traumatic Brain Injury.

    PubMed

    Semple, Bridgette D; Carlson, Jaclyn; Noble-Haeusslein, Linda J

    2016-01-01

    Due to a high incidence of traumatic brain injury (TBI) in children and adolescents, age-specific studies are necessary to fully understand the long-term consequences of injuries to the immature brain. Preclinical and translational research can help elucidate the vulnerabilities of the developing brain to insult, and provide model systems to formulate and evaluate potential treatments aimed at minimizing the adverse effects of TBI. Several experimental TBI models have therefore been scaled down from adult rodents for use in juvenile animals. The following chapter discusses these adapted models for pediatric TBI, and the importance of age equivalence across species during model development and interpretation. Many neurodevelopmental processes are ongoing throughout childhood and adolescence, such that neuropathological mechanisms secondary to a brain insult, including oxidative stress, metabolic dysfunction and inflammation, may be influenced by the age at the time of insult. The long-term evaluation of clinically relevant functional outcomes is imperative to better understand the persistence and evolution of behavioral deficits over time after injury to the developing brain. Strategies to modify or protect against the chronic consequences of pediatric TBI, by supporting the trajectory of normal brain development, have the potential to improve quality of life for brain-injured children.

  9. Cellular scaling rules for rodent brains

    PubMed Central

    Herculano-Houzel, Suzana; Mota, Bruno; Lent, Roberto

    2006-01-01

    How do cell number and size determine brain size? Here, we show that, in the order Rodentia, increased size of the cerebral cortex, cerebellum, and remaining areas across six species is achieved through greater numbers of neurons of larger size, and much greater numbers of nonneuronal cells of roughly invariant size, such that the ratio between total neuronal and nonneuronal mass remains constant across species. Although relative cerebellar size remains stable among rodents, the number of cerebellar neurons increases with brain size more rapidly than in the cortex, such that the cerebellar fraction of total brain neurons increases with brain size. In contrast, although the relative cortical size increases with total brain size, the cortical fraction of total brain neurons remains constant. We propose that the faster increase in average neuronal size in the cerebral cortex than in the cerebellum as these structures gain neurons and the rapidly increasing glial numbers that generate glial mass to match total neuronal mass at a fixed glia/neuron total mass ratio are fundamental cellular constraints that lead to the relative expansion of cerebral cortical volume across species. PMID:16880386

  10. Hindlimb unloading rodent model: technical aspects

    NASA Technical Reports Server (NTRS)

    Morey-Holton, Emily R.; Globus, Ruth K.

    2002-01-01

    Since its inception at the National Aeronautics and Space Administration (NASA) Ames Research Center in the mid-1970s, many laboratories around the world have used the rat hindlimb unloading model to simulate weightlessness and to study various aspects of musculoskeletal loading. In this model, the hindlimbs of rodents are elevated to produce a 30 degrees head-down tilt, which results in a cephalad fluid shift and avoids weightbearing by the hindquarters. Although several reviews have described scientific results obtained with this model, this is the first review to focus on the technical aspects of hindlimb unloading. This review includes a history of the technique, a brief comparison with spaceflight data, technical details, extension of the model to mice, and other important technical considerations (e.g., housing, room temperature, unloading angle, the potential need for multiple control groups, age, body weight, the use of the forelimb tissues as internal controls, and when to remove animals from experiments). This paper is intended as a reference for researchers, reviewers of manuscripts, and institutional animal care and use committees. Over 800 references, related to the hindlimb unloading model, can be accessed via the electronic version of this article.

  11. Assessing Spatial Learning and Memory in Rodents

    PubMed Central

    Vorhees, Charles V.; Williams, Michael T.

    2014-01-01

    Maneuvering safely through the environment is central to survival of almost all species. The ability to do this depends on learning and remembering locations. This capacity is encoded in the brain by two systems: one using cues outside the organism (distal cues), allocentric navigation, and one using self-movement, internal cues and nearby proximal cues, egocentric navigation. Allocentric navigation involves the hippocampus, entorhinal cortex, and surrounding structures; in humans this system encodes allocentric, semantic, and episodic memory. This form of memory is assessed in laboratory animals in many ways, but the dominant form of assessment is the Morris water maze (MWM). Egocentric navigation involves the dorsal striatum and connected structures; in humans this system encodes routes and integrated paths and, when overlearned, becomes procedural memory. In this article, several allocentric assessment methods for rodents are reviewed and compared with the MWM. MWM advantages (little training required, no food deprivation, ease of testing, rapid and reliable learning, insensitivity to differences in body weight and appetite, absence of nonperformers, control methods for proximal cue learning, and performance effects) and disadvantages (concern about stress, perhaps not as sensitive for working memory) are discussed. Evidence-based design improvements and testing methods are reviewed for both rats and mice. Experimental factors that apply generally to spatial navigation and to MWM specifically are considered. It is concluded that, on balance, the MWM has more advantages than disadvantages and compares favorably with other allocentric navigation tasks. PMID:25225309

  12. Rodent models of neuroinflammation for Alzheimer's disease.

    PubMed

    Nazem, Amir; Sankowski, Roman; Bacher, Michael; Al-Abed, Yousef

    2015-04-17

    Alzheimer's disease remains incurable, and the failures of current disease-modifying strategies for Alzheimer's disease could be attributed to a lack of in vivo models that recapitulate the underlying etiology of late-onset Alzheimer's disease. The etiology of late-onset Alzheimer's disease is not based on mutations related to amyloid-β (Aβ) or tau production which are currently the basis of in vivo models of Alzheimer's disease. It has recently been suggested that mechanisms like chronic neuroinflammation may occur prior to amyloid-β and tau pathologies in late-onset Alzheimer's disease. The aim of this study is to analyze the characteristics of rodent models of neuroinflammation in late-onset Alzheimer's disease. Our search criteria were based on characteristics of an idealistic disease model that should recapitulate causes, symptoms, and lesions in a chronological order similar to the actual disease. Therefore, a model based on the inflammation hypothesis of late-onset Alzheimer's disease should include the following features: (i) primary chronic neuroinflammation, (ii) manifestations of memory and cognitive impairment, and (iii) late development of tau and Aβ pathologies. The following models fit the pre-defined criteria: lipopolysaccharide- and PolyI:C-induced models of immune challenge; streptozotocin-, okadaic acid-, and colchicine neurotoxin-induced neuroinflammation models, as well as interleukin-1β, anti-nerve growth factor and p25 transgenic models. Among these models, streptozotocin, PolyI:C-induced, and p25 neuroinflammation models are compatible with the inflammation hypothesis of Alzheimer's disease.

  13. A NEW METHOD TO QUANTIFY CORE TEMPERATURE INSTABILITY IN RODENTS.

    EPA Science Inventory

    Methods to quantify instability of autonomic systems such as temperature regulation should be important in toxicant and drug safety studies. Stability of core temperature (Tc) in laboratory rodents is susceptible to a variety of stimuli. Calculating the temperature differential o...

  14. Occurrence of ectoparasites on rodents in Sukhothai Province, northern Thailand.

    PubMed

    Changbunjong, Tanasak; Weluwanarak, Thekhawet; Chamsai, Tatiyanuch; Sedwisai, Poonyapat; Ngamloephochit, Seni; Suwanpakdee, Sarin; Yongyuttawichai, Plern; Wiratsudakul, Anuwat; Chaichoun, Kridsada; Ratanakorn, Parntep

    2010-11-01

    A survey of ectoparasites on rodents was carried out bimonthly from April 2008 to March 2009 in 3 districts of Sukhothai Province, northern Thailand. A total of 130 rodents comprising 8 species of hosts were captured and examined for ectoparasites. The hosts examined were Bandicota indica, Bandicota savilei, Rattus losea, Rattus rattus, Rattus exulans, Rattus norvegicus, Menetes berdmorei and Tamiops mcclellandii. Ninety-seven ectoparasites were collected: 1 species of tick (Hemaphysalis bandicota), 2 species of mites (Laelaps nuttali and Laelaps echidninus), and 1 species of flea (Xenopsylla cheopis) were identified. The infestation rates by ticks, mites and fleas on the rodents were 0.77, 5.38 and 6.15%, respectively. Monitoring the rodent population and their ectoparasites is important for future planning of prevention and control of zoonotic diseases in the area.

  15. Bone morphology of the hind limbs in two caviomorph rodents.

    PubMed

    de Araújo, F A P; Sesoko, N F; Rahal, S C; Teixeira, C R; Müller, T R; Machado, M R F

    2013-04-01

    In order to evaluate the hind limbs of caviomorph rodents a descriptive analysis of the Cuniculus paca (Linnaeus, 1766) and Hydrochoerus hydrochaeris (Linnaeus, 1766) was performed using anatomical specimens, radiography, computed tomography (CT) and full-coloured prototype models to generate bone anatomy data. The appendicular skeleton of the two largest rodents of Neotropical America was compared with the previously reported anatomical features of Rattus norvegicus (Berkenhout, 1769) and domestic Cavia porcellus (Linnaeus, 1758). The structures were analyzed macroscopically and particular findings of each species reported. Features including the presence of articular fibular projection and lunulae were observed in the stifle joint of all rodents. Imaging aided in anatomical description and, specifically in the identification of bone structures in Cuniculus paca and Hydrochoerus hydrochaeris. The imaging findings were correlated with the anatomical structures observed. The data may be used in future studies comparing these animals to other rodents and mammalian species.

  16. First Isolates of Leptospira spp., from Rodents Captured in Angola

    PubMed Central

    Fortes-Gabriel, Elsa; Carreira, Teresa; Vieira, Maria Luísa

    2016-01-01

    Rodents play an important role in the transmission of pathogenic Leptospira spp. However, in Angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. Regarding this gap, we captured rodents in Luanda and Huambo provinces to identify circulating Leptospira spp. Rodent kidney tissue was cultured and DNA amplified and sequenced. Culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (PCR) and sequencing were also performed. A total of 37 rodents were captured: Rattus rattus (15, 40.5%), Rattus norvegicus (9, 24.3%), and Mus musculus (13, 35.2%). Leptospiral DNA was amplified in eight (21.6%) kidney samples. From the cultures, we obtained four (10.8%) Leptospira isolates belonging to the Icterohaemorrhagiae and Ballum serogroups of Leptospira interrogans and Leptospira borgpetersenii genospecies, respectively. This study provides information about circulating leptospires spread by rats and mice in Angola. PMID:26928840

  17. First Isolates of Leptospira spp., from Rodents Captured in Angola.

    PubMed

    Fortes-Gabriel, Elsa; Carreira, Teresa; Vieira, Maria Luísa

    2016-05-04

    Rodents play an important role in the transmission of pathogenic Leptospira spp. However, in Angola, neither the natural reservoirs of these spirochetes nor leptospirosis diagnosis has been considered. Regarding this gap, we captured rodents in Luanda and Huambo provinces to identify circulating Leptospira spp. Rodent kidney tissue was cultured and DNA amplified and sequenced. Culture isolates were evaluated for pathogenic status and typing with rabbit antisera; polymerase chain reaction (PCR) and sequencing were also performed. A total of 37 rodents were captured: Rattus rattus (15, 40.5%), Rattus norvegicus (9, 24.3%), and Mus musculus (13, 35.2%). Leptospiral DNA was amplified in eight (21.6%) kidney samples. From the cultures, we obtained four (10.8%) Leptospira isolates belonging to the Icterohaemorrhagiae and Ballum serogroups of Leptospira interrogans and Leptospira borgpetersenii genospecies, respectively. This study provides information about circulating leptospires spread by rats and mice in Angola.

  18. Rodent-associated Bartonella Febrile Illness, Southwestern United States

    PubMed Central

    Iralu, Jonathan; Bai, Ying; Crook, Larry; Tempest, Bruce; Simpson, Gary; McKenzie, Taylor

    2006-01-01

    Serum specimens from 114 patients hospitalized with a febrile illness were tested with an indirect immunofluorescence assay (IFA) using Bartonella antigens prepared from 6 species of sigmodontine rodents and 3 known human Bartonella pathogens: B. henselae, B. quintana, and B. elizabethae. Acute- and convalescent-phase serum samples from 5 of these patients showed seroconversion with an IFA titer >512 to rodent-associated Bartonella antigens. The highest titer was against antigen derived from the white-throated woodrat (Neotoma albigula), although this rodent is not necessarily implicated as the source of infection. Three of the 5 who seroconverted showed no cross-reaction to the 3 Bartonella human pathogens. Common clinical characteristics were fever, chills, myalgias, leukopenia, thrombocytopenia, and transaminasemia. Although antibodies to Bartonella are cross-reactive, high-titer seroconversions to rodent-associated Bartonella antigens in adults with common clinical characteristics should stimulate the search for additional Bartonella human pathogens. PMID:16836824

  19. Transmission ecology of rodent-borne diseases: New frontiers.

    PubMed

    Bordes, Frédéric; Blasdell, Kim; Morand, Serge

    2015-09-01

    Rodents are recognized reservoir hosts for many human zoonotic pathogens. The current trends resulting from anthropocene defaunation suggest that in the future they, along with other small mammals, are likely to become the dominant mammals in almost all human-modified environments. Recent intricate studies on bat-borne emerging diseases have highlighted that many gaps exist in our understanding of the zoonotic transmission of rodent-borne pathogens. This has emphasized the need for scientists interested in rodent-borne diseases to integrate rodent ecology into their analysis of rodent-borne pathogen transmission in order to identify in more detail the mechanisms of spillover and chains of transmission. Further studies are required to better understand the true impact of rodent abundance and the importance of pathogen sharing and circulation in multi-host- multi-pathogen communities. We also need to explore in more depth the roles of generalist and abundant species as the potential links between pathogen-sharing, co-infections and disease transmission.

  20. Immunological Mechanisms Mediating Hantavirus Persistence in Rodent Reservoirs

    PubMed Central

    Easterbrook, Judith D.; Klein, Sabra L.

    2008-01-01

    Hantaviruses, similar to several emerging zoonotic viruses, persistently infect their natural reservoir hosts, without causing overt signs of disease. Spillover to incidental human hosts results in morbidity and mortality mediated by excessive proinflammatory and cellular immune responses. The mechanisms mediating the persistence of hantaviruses and the absence of clinical symptoms in rodent reservoirs are only starting to be uncovered. Recent studies indicate that during hantavirus infection, proinflammatory and antiviral responses are reduced and regulatory responses are elevated at sites of increased virus replication in rodents. The recent discovery of structural and non-structural proteins that suppress type I interferon responses in humans suggests that immune responses in rodent hosts could be mediated directly by the virus. Alternatively, several host factors, including sex steroids, glucocorticoids, and genetic factors, are reported to alter host susceptibility and may contribute to persistence of hantaviruses in rodents. Humans and reservoir hosts differ in infection outcomes and in immune responses to hantavirus infection; thus, understanding the mechanisms mediating viral persistence and the absence of disease in rodents may provide insight into the prevention and treatment of disease in humans. Consideration of the coevolutionary mechanisms mediating hantaviral persistence and rodent host survival is providing insight into the mechanisms by which zoonotic viruses have remained in the environment for millions of years and continue to be transmitted to humans. PMID:19043585

  1. Ectoparasites of Rodents Captured in Hamedan, Western Iran

    PubMed Central

    Zendehfili, Hamid; Zahirnia, Amir Hossein; Maghsood, Amir Hossein; Khanjani, Mohammad; Fallah, Mohammad

    2015-01-01

    Background: Rodents with a population greater than the entire population of other mammals on earth are the source of economic losses and health conflicts. One of the major health problems with the rodents is their role as reservoir hosts of zoonotic diseases. The aim of this study was to assess the infestation of commensal rodents with ectoparasites in Hamedan City, Western Iran. Methods: The samples were collected by live traps during years 2012–2013. After transferring the samples to the Entomological Laboratory of Hamedan University of Medical Sciences, their ectoparasites were collected and identified. Results: A total of 171 slides were prepared from 105 captured commensal rodents: Mus musculus, Rattus rattus and R. norvegicus comprising three orders namely Mesostigmata: Hypoaspis (Laelaspis) astronomica, Dermanyssius sp, Pachylaelapidae (male). Metastigmata: Rhipicephalus sp and Anoplura: Polyplax spinulosa were recovered in Hamedan City. Seventy (66.6%) rodents were found infested with at least one species of ectoparasites. Conclusion: The results of our study indicate that ectoparasites infestation in commensal rodents of Hamedan city is high and more attention by local health authorities is needed to prevent zoonotic diseases. PMID:26623438

  2. Expression of ORAI1, a Plasma Membrane Resident Subunit of the CRAC Channel, in Rodent and Non-rodent Species

    PubMed Central

    Guzman, Roberto; Valente, Eliane G.; Pretorius, Jim; Pacheco, Efrain; Qi, Meiying; Bennett, Brian D.; Fong, David H.; Lin, Fen-Fen; Bi, Vivian

    2014-01-01

    We determined the expression of ORAI1 protein in rodent and non-rodent tissues using a monoclonal antibody directed against an extracellular loop of the protein. Previous reports using antibodies directed at the C-terminus of ORAI1 have not detected central nervous system (CNS) expression. Our results demonstrate broad tissue expression that includes the CNS using a unique monoclonal antibody specific to an extracellular loop of ORAI1. In addition, we present in situ hybridization (ISH) results using a probe within the middle of the mouse coding region showing CNS expression of Orai1 RNA. We contrast the patterns of rodent and human tissue expression and conclude that rodents have similar expression of ORAI1 in most tissue types when compared to primates, with an important exception being the male reproductive system, where human-specific expression is observed. PMID:25249026

  3. Ecological and Control Techniques for Sand Flies (Diptera: Psychodidae) Associated with Rodent Reservoirs of Leishmaniasis

    DTIC Science & Technology

    2013-09-12

    found naturally in plant and animal tissues was highly effective for linking adult sand flies with their larval diet, without having to locate or capture...on rodent feces. Through the identification of rodent feces as a sand fly larval habitat, we now know that rodent baits containing insecticides that...rodents, and that the elimination of sand flies that feed on rodents can be achieved using baits containing an insecticide that circulates in the blood of

  4. Developmental toxicity of engineered nanomaterials in rodents.

    PubMed

    Ema, Makoto; Gamo, Masashi; Honda, Kazumasa

    2016-05-15

    We summarized significant effects reported in the literature on the developmental toxicity of engineered nanomaterials (ENMs) in rodents. The developmental toxicity of ENMs included not only structural abnormalities, but also death, growth retardation, and behavioral and functional abnormalities. Most studies were performed on mice using an injection route of exposure. Teratogenic effects were indicated when multi-walled carbon nanotubes (MWCNTs), single-walled carbon nanotubes (SWCNTs), and TiO2-nanoparticles were administered to mice during early gestation. Reactive oxygen species levels were increased in placentas and malformed fetuses and their placentas after prenatal exposure to MWCNTs and SWCNTs, respectively. The pre- and postnatal mortalities and growth retardation in offspring increased after prenatal exposure to ENMs. Histopathological and functional abnormalities were also induced in placentas after prenatal exposure to ENMs. Maternal exposure to ENMs induced behavioral alterations, histopathological and biochemical changes in the central nervous system, increased susceptibility to allergy, transplacental genotoxicity, and vascular, immunological, and reproductive effects in offspring. The size- and developmental stage-dependent placental transfer of ENMs was noted after maternal exposure. Silver accumulated in the visceral yolk sac after being injected with Ag-NPs during early gestation. Although currently available data has provided initial information on the potential developmental toxicity of ENMs, that on the developmental toxicity of ENMs is still very limited. Further studies using well-characterized ENMs, state-of the-art study protocols, and appropriate routes of exposure are required in order to clarify these developmental effects and provide information suitable for risk assessments of ENMs.

  5. A novel platform device for rodent echocardiography.

    PubMed

    Kutschka, Ingo; Sheikh, Ahmad Y; Sista, Ramachandra; Hendry, Stephen L; Chun, Hyung J; Hoyt, Grant; Kutschka, Werner; Pelletier, Marc P; Quertermous, Tom; Wu, Joseph C; Robbins, Robert C

    2007-06-06

    Acquisition of echocardiographic data from rodents is subject to wide variability due to variations in technique. We hypothesize that a dedicated imaging platform can aid in standardization of technique and improve the quality of images obtained. We constructed a device consisting of a boom-mounted steel platform frame (25 x 35 x 3 cm) on which a transparent polyethylene membrane is mounted. The animal is placed onto the membrane and receives continual inhaled anesthesia via an integrated port. The membrane allows for probe positioning from beneath the animal to obtain standard echo-views in left lateral decubitus or prone positions. The frame can be set at any desired angle ranging from 0 to 360 degrees along either the long or short axis. Adult male Sprague-Dawley rats (n = 5) underwent echocardiography (General Electric, Vivid 7, 14 MHz) using the platform. The device allowed for optimal positioning of animals for a variety of standard echocardiographic measurements. Evaluations among all animals showed minimal variability between two different operators and time points. We tested the feasibility of the device for supporting the assessment of cardiac function in a disease model by evaluating a separate cohort of adult male spontaneously hypertensive rats (n = 5) that underwent left anterior descending coronary artery ligation. Serial echocardiography demonstrated statistically significant decreases of fractional shortening and ejection fraction (p < 0.01) 240 days after surgery. Our novel imaging platform allowed for consistent collection of high-quality echocardiographic data from rats. Future studies will focus on improving this technology to allow for standardized high-throughput echocardiographic analysis in small animal models of disease.

  6. Rodent models of diabetic nephropathy: their utility and limitations

    PubMed Central

    Kitada, Munehiro; Ogura, Yoshio; Koya, Daisuke

    2016-01-01

    Diabetic nephropathy is the most common cause of end-stage renal disease. Therefore, novel therapies for the suppression of diabetic nephropathy must be developed. Rodent models are useful for elucidating the pathogenesis of diseases and testing novel therapies, and many type 1 and type 2 diabetic rodent models have been established for the study of diabetes and diabetic complications. Streptozotocin (STZ)-induced diabetic animals are widely used as a model of type 1 diabetes. Akita diabetic mice that have an Ins2+/C96Y mutation and OVE26 mice that overexpress calmodulin in pancreatic β-cells serve as a genetic model of type 1 diabetes. In addition, db/db mice, KK-Ay mice, Zucker diabetic fatty rats, Wistar fatty rats, Otsuka Long-Evans Tokushima Fatty rats and Goto-Kakizaki rats serve as rodent models of type 2 diabetes. An animal model of diabetic nephropathy should exhibit progressive albuminuria and a decrease in renal function, as well as the characteristic histological changes in the glomeruli and the tubulointerstitial lesions that are observed in cases of human diabetic nephropathy. A rodent model that strongly exhibits all these features of human diabetic nephropathy has not yet been developed. However, the currently available rodent models of diabetes can be useful in the study of diabetic nephropathy by increasing our understanding of the features of each diabetic rodent model. Furthermore, the genetic background and strain of each mouse model result in differences in susceptibility to diabetic nephropathy with albuminuria and the development of glomerular and tubulointerstitial lesions. Therefore, the validation of an animal model reproducing human diabetic nephropathy will significantly facilitate our understanding of the underlying genetic mechanisms that contribute to the development of diabetic nephropathy. In this review, we focus on rodent models of diabetes and discuss the utility and limitations of these models for the study of diabetic

  7. Rodent models of diabetic nephropathy: their utility and limitations.

    PubMed

    Kitada, Munehiro; Ogura, Yoshio; Koya, Daisuke

    2016-01-01

    Diabetic nephropathy is the most common cause of end-stage renal disease. Therefore, novel therapies for the suppression of diabetic nephropathy must be developed. Rodent models are useful for elucidating the pathogenesis of diseases and testing novel therapies, and many type 1 and type 2 diabetic rodent models have been established for the study of diabetes and diabetic complications. Streptozotocin (STZ)-induced diabetic animals are widely used as a model of type 1 diabetes. Akita diabetic mice that have an Ins2+/C96Y mutation and OVE26 mice that overexpress calmodulin in pancreatic β-cells serve as a genetic model of type 1 diabetes. In addition, db/db mice, KK-Ay mice, Zucker diabetic fatty rats, Wistar fatty rats, Otsuka Long-Evans Tokushima Fatty rats and Goto-Kakizaki rats serve as rodent models of type 2 diabetes. An animal model of diabetic nephropathy should exhibit progressive albuminuria and a decrease in renal function, as well as the characteristic histological changes in the glomeruli and the tubulointerstitial lesions that are observed in cases of human diabetic nephropathy. A rodent model that strongly exhibits all these features of human diabetic nephropathy has not yet been developed. However, the currently available rodent models of diabetes can be useful in the study of diabetic nephropathy by increasing our understanding of the features of each diabetic rodent model. Furthermore, the genetic background and strain of each mouse model result in differences in susceptibility to diabetic nephropathy with albuminuria and the development of glomerular and tubulointerstitial lesions. Therefore, the validation of an animal model reproducing human diabetic nephropathy will significantly facilitate our understanding of the underlying genetic mechanisms that contribute to the development of diabetic nephropathy. In this review, we focus on rodent models of diabetes and discuss the utility and limitations of these models for the study of diabetic

  8. Serovars of Leptospira isolated from dogs and rodents.

    PubMed

    Suepaul, S M; Carrington, C V F; Campbell, M; Borde, G; Adesiyun, A A

    2010-07-01

    We determined the frequency of isolation of Leptospira from dogs and rodents, the serovars of Leptospira, and the clinical, gross and histological manifestations in dogs with leptospirosis in Trinidad. From dogs, samples of urine, blood and kidney were collected while only kidney and blood samples of trapped rodents were used. Isolates were cultured and serotyped using a panel of 23 international serovars and monoclonal antibodies. The risk factors for leptospirosis were also determined in owned dogs using a standard questionnaire. Of a total of 468 animals investigated for Leptospira, 70 (15.0%) were positive, comprising nine (18.0%) of 50 suspected canine leptospirosis cases, seven (3.4%) of 207 stray dogs and 54 (25.6%) of 211 rodents. The observation that rodents have a statistically (P<0.05, chi2) higher frequency of isolation emphasizes the importance of rodents as reservoirs of leptospirosis in the country. Copenhageni was the predominant serovar found in 100.0% (7/7), 33.3% (2/6) and 68.5% (37/54) of isolates from suspected canine leptospirosis cases, stray dogs and rodents, respectively. Serovars Icterohaemorrhagiae and Canicola, the two serovars present in the commercial vaccines used locally, were detected in one (1.5%) and zero (0.0%) isolates respectively of the 67 tested. Data provided suggest that the apparent vaccine failure may be a consequence of the fact that the predominant serovar (Copenhageni) detected in sick, apparently healthy dogs and in rodents is not contained in the vaccines used locally to protect dogs against canine leptospirosis.

  9. Hypergravity Effects on Rodent Pregnancy and Parturition

    NASA Technical Reports Server (NTRS)

    Ronca, A. E.; Baer, L. A.; Mills, N. A.; Wade, C. E.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    No mammal has yet undergone birth, or parturition, in the microgravity of space. Previous studies (Ronco & Alberts, 2000) have shown that mid-pregnant rat dams exposed to spaceflight (0-g) and landed 48-72 hrs before term successfully delivered robust, healthy offspring Microgravity-exposed dams exhibited twice the expected numbers of labor contractions whereas length of pregnancy, duration of labor, fetal wastage, number of neonates born and litter gender ratios were identical to controls. In the present study, we report the results of rodent pregnancy and parturition at the opposite end of the gravity spectrum, in hypergravity. Dams exposed to either: 1.0-g, 1.5-g, 1.75-g or 2.0-g from Gestational day (G) 11 and throughout the births of their litters had comparable pregnancy and labor durations, fetal wastage, numbers of neonates born and litter Tender ratios. During parturition, hypergravity-exposed dams exhibited significantly fewer labor contractions as compared to 1.0-g controls. Dams that underwent birth in hypergravity had significantly fewer offspring surviving the immediate postpartum period (P1: 1.0-g, 11.92 +/- 2.84; 1.5-g, 10.88 +/- 2.17; 1.75-g, 9.22 +/-1.99; 2.0-g, 8.83 +/- 3.31). Within 24 hrs postpartum, neonatal survival was further diminished in hypergravity [P2: 100% (1.0-g); 96% (1.5-g); 96% (1.75-g); 73% (2.0-g)] and continued to decline (P10: 100%(1.0-g.); 90%(1.5-g); 87%(1.75-g), 40%(2.0-g)]. Neonatal losses stabilized by P5 for the 1.5-g andl.75-g conditions but continued until P9 for the 2.0-g condition. Together, these findings show that postnatal, but not prenatal, survival is compromised following birth in hypergravity, Maternal and neonatal factors that contribute to peri-parturitional vulnerability to altered gravity environments will be discussed.

  10. Global parasite and Rattus rodent invasions: The consequences for rodent-borne diseases.

    PubMed

    Morand, Serge; Bordes, Frédéric; Chen, Hsuan-Wien; Claude, Julien; Cosson, Jean-François; Galan, Maxime; Czirják, Gábor Á; Greenwood, Alex D; Latinne, Alice; Michaux, Johan; Ribas, Alexis

    2015-09-01

    We summarize the current knowledge on parasitism-related invasion processes of the globally invasive Rattus lineages, originating from Asia, and how these invasions have impacted the local epidemiology of rodent-borne diseases. Parasites play an important role in the invasion processes and successes of their hosts through multiple biological mechanisms such as "parasite release," "immunocompetence advantage," "biotic resistance" and "novel weapon." Parasites may also greatly increase the impact of invasions by spillover of parasites and other pathogens, introduced with invasive hosts, into new hosts, potentially leading to novel emerging diseases. Another potential impact is the ability of the invader to amplify local parasites by spillback. In both cases, local fauna and humans may be exposed to new health risks, which may decrease biodiversity and potentially cause increases in human morbidity and mortality. Here we review the current knowledge on these processes and propose some research priorities.

  11. Lassa fever or lassa hemorrhagic fever risk to humans from rodent-borne zoonoses.

    PubMed

    El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A

    2015-04-01

    Viral hemorrhagic fevers (VHFs) typically manifest as rapidly progressing acute febrile syndromes with profound hemorrhagic manifestations and very high fatality rates. Lassa fever, an acute hemorrhagic fever characterized by fever, muscle aches, sore throat, nausea, vomiting, diarrhea and chest and abdominal pain. Rodents are important reservoirs of rodent-borne zoonosis worldwide. Transmission rodents to humans occur by aerosol spread, either from the genus Mastomys rodents' excreta (multimammate rat) or through the close contact with infected patients (nosocomial infection). Other rodents of the genera Rattus, Mus, Lemniscomys, and Praomys are incriminated rodents hosts. Now one may ask do the rodents' ectoparasites play a role in Lassa virus zoonotic transmission. This paper summarized the update knowledge on LHV; hopping it might be useful to the clinicians, nursing staff, laboratories' personals as well as those concerned zoonoses from rodents and rodent control.

  12. Fibroblasts From Long-Lived Rodent Species Exclude Cadmium

    PubMed Central

    Dostál, Lubomír; Kohler, William M.; Penner-Hahn, James E.; Miller, Richard A.

    2015-01-01

    Resistance to the lethal effects of cellular stressors, including the toxic heavy metal cadmium (Cd), is characteristic of fibroblast cell lines derived from long-lived bird and rodent species, as well as cell lines from several varieties of long-lived mutant mice. To explore the mechanism of resistance to Cd, we used inductively coupled plasma mass spectroscopy to measure the rate of Cd uptake into primary fibroblasts of 15 rodent species. These data indicate that fibroblasts from long-lived rodent species have slower rates of Cd uptake from the extracellular medium than those from short-lived species. In addition, fibroblasts from short-lived species export more zinc after exposure to extracellular Cd than cells from long-lived species. Lastly, fibroblasts from long-lived rodent species have lower baseline concentrations of two redox-active metals, iron and copper. Our results suggest that evolution of longevity among rodents required adjustment of cellular properties to alter metal homeostasis and to reduce the toxic effects of heavy metals that accumulate over the course of a longer life span. PMID:24522391

  13. Fibroblasts from long-lived rodent species exclude cadmium.

    PubMed

    Dostál, Lubomír; Kohler, William M; Penner-Hahn, James E; Miller, Richard A; Fierke, Carol A

    2015-01-01

    Resistance to the lethal effects of cellular stressors, including the toxic heavy metal cadmium (Cd), is characteristic of fibroblast cell lines derived from long-lived bird and rodent species, as well as cell lines from several varieties of long-lived mutant mice. To explore the mechanism of resistance to Cd, we used inductively coupled plasma mass spectroscopy to measure the rate of Cd uptake into primary fibroblasts of 15 rodent species. These data indicate that fibroblasts from long-lived rodent species have slower rates of Cd uptake from the extracellular medium than those from short-lived species. In addition, fibroblasts from short-lived species export more zinc after exposure to extracellular Cd than cells from long-lived species. Lastly, fibroblasts from long-lived rodent species have lower baseline concentrations of two redox-active metals, iron and copper. Our results suggest that evolution of longevity among rodents required adjustment of cellular properties to alter metal homeostasis and to reduce the toxic effects of heavy metals that accumulate over the course of a longer life span.

  14. Plant Secondary Metabolites as Rodent Repellents: a Systematic Review.

    PubMed

    Hansen, Sabine C; Stolter, Caroline; Imholt, Christian; Jacob, Jens

    2016-09-01

    The vast number of plant secondary metabolites (PSMs) produced by higher plants has generated many efforts to exploit their potential for pest control. We performed a systematic literature search to retrieve relevant publications, and we evaluated these according to PSM groups to derive information about the potential for developing plant-derived rodent repellents. We screened a total of 54 publications where different compounds or plants were tested regarding rodent behavior/metabolism. In the search for widely applicable products, we recommend multi-species systematic screening of PSMs, especially from the essential oil and terpenoid group, as laboratory experiments have uniformly shown the strongest effects across species. Other groups of compounds might be more suitable for the management of species-specific or sex-specific issues, as the effects of some compounds on particular rodent target species or sex might not be present in non-target species or in both sexes. Although plant metabolites have potential as a tool for ecologically-based rodent management, this review demonstrates inconsistent success across laboratory, enclosure, and field studies, which ultimately has lead to a small number of currently registered PSM-based rodent repellents.

  15. Distribution and characteristics of rodent picornaviruses in China

    PubMed Central

    Du, Jiang; Lu, Liang; Liu, Feng; Su, Haoxiang; Dong, Jie; Sun, Lilian; Zhu, Yafang; Ren, Xianwen; Yang, Fan; Guo, Fei; Liu, Qiyong; Wu, Zhiqiang; Jin, Qi

    2016-01-01

    Rodents are important reservoir hosts of many important zoonotic viruses. The family Picornaviridae contains clinically important pathogens that infect humans and animals, and increasing numbers of rodent picornaviruses have recently been associated with zoonoses. We collected 574 pharyngeal and anal swab specimens from 287 rodents of 10 different species from eight representative regions of China from October 2013 to July 2015. Seven representative sequences identified from six rodent species were amplified as full genomes and classified into four lineages. Three lineage 1 viruses belonged to a novel genus of picornaviruses and was more closely related to Hepatovirus than to others genera of picornaviruses based on aa homology. Lineage 2, lineage 3, and lineage 4 viruses belonged to the genera Rosavirus, Hunnivirus, and Enterovirus, respectively, representing new species. According to both phylogenetic and identity analyses, Lineage 2 viruses had a close relationship with rosavirus 2 which was recovered from the feces of a child in Gambia and Lineage 3 viruses had a close relationship with domestic animal Hunnivirus. Lineage 4 viruses provide the first evidence of these enteroviruses and their evolution in rodent hosts in China. PMID:27682620

  16. Effects of lersivirine on canine and rodent thyroid function.

    PubMed

    Houle, Christopher D; Finch, Gregory L; Mauthe, Robert J; Potter, David M; Walisser, Jacqueline A; Gardner, Iain B; DeWit, Robert H

    2014-07-01

    Lersivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) being developed for the treatment of HIV-1 infection. Like other NNRTIs, lersivirine is a potent enzyme inducer in rodents capable of inducing a number of hepatic enzymes including those involved in its own metabolism. Preclinically lersivirine has been associated with hepatocellular hypertrophy and thyroid gland follicular cell hypertrophy in rats, mice, and dogs. In rodents, we show that development of thyroid hypertrophy is related to the classic mechanism, namely increased thyroxine (T4) clearance secondary to induction of uridine-diphosphoglucuronosyltransferase (UDPGT) in the liver and a resulting increase in thyroid-stimulating hormone. Similarly, lersivirine-exposed dogs exhibit a significant increase in hepatic UDPGT enzyme activity along with increased T4 clearance although clear effects on serum thyroid hormone levels were less apparent. These effects on thyroid hormonal clearance in the dog suggest that thyroid gland hypertrophy in this species is due to the same mechanism shown to occur in rodents although, as expected, dogs better adapt to these effects and therefore maintain relatively normal thyroid hormonal balance. It is also notable that the minimal thyroid follicular hypertrophy that occurs in dogs does not progress as is seen in rodents. As is the case with rodents, these adaptive changes in the dog are not considered indicative of a human health risk.

  17. Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

    PubMed Central

    Mercier, Aurélien; Garba, Madougou; Bonnabau, Henri; Kane, Mamadou; Rossi, Jean-Pierre; Dardé, Marie-Laure; Dobigny, Gauthier

    2013-01-01

    A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents - that we reviewed here - which altogether show that Toxoplasma seroprevalence in rodent is highly variable, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be further scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel. PMID:23828008

  18. Thieving rodents as substitute dispersers of megafaunal seeds

    PubMed Central

    Jansen, Patrick A.; Hirsch, Ben T.; Emsens, Willem-Jan; Zamora-Gutierrez, Veronica; Wikelski, Martin; Kays, Roland

    2012-01-01

    The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees. PMID:22802644

  19. Ectoparasites of commensal rodents in Talkha Center, Dakahlia Governorate, Egypt.

    PubMed

    El Kady, Gamal A; El Shazly, Atef M; Mikhail, Micheal W; Bahgat, Iman M

    2007-12-01

    The ecto-parasites infesting commensally rodents were collected from the different localities in Talkha Center (Dakahlia Governorate) from April 2006 to March 2007. The seasonal abundance of rodent number and rat index was 52 (0.58) in spring, 27 (0.3) in summer, 39 (0.22) in autumn and 17 (0.05) in winter. From 135 rodent species and rat index was Rattus norvegicus N=33 (0.24), R. r. frugivorous N=39 (0.29); R. r. alexandrinus N=48 (0.36) and Mus musculus N=15 (0.11). From 388 ecto-parasite infested rodent collected number and ecto index was fleas N= 114 (0.84 flea/rat), Lice N=93 (0.69 lice/rat), Mites N = 165 (1.2 mite/rat) and larva of ticks N=16 (0.12 tick/rat). No doubt, rodents and their ectoparasites played a serious role in spreading and transmission of zoonotic diseases to human and animal.

  20. Methodological considerations for measuring spontaneous physical activity in rodents.

    PubMed

    Teske, Jennifer A; Perez-Leighton, Claudio E; Billington, Charles J; Kotz, Catherine M

    2014-05-15

    When exploring biological determinants of spontaneous physical activity (SPA), it is critical to consider whether methodological factors differentially affect rodents and the measured SPA. We determined whether acclimation time, sensory stimulation, vendor, or chamber size affected measures in rodents with varying propensity for SPA. We used principal component analysis to determine which SPA components (ambulatory and vertical counts, time in SPA, and distance traveled) best described the variability in SPA measurements. We compared radiotelemetry and infrared photobeams used to measure SPA and exploratory activity. Acclimation time, sensory stimulation, vendor, and chamber size independently influenced SPA, and the effect was moderated by the propensity for SPA. A 24-h acclimation period prior to SPA measurement was sufficient for habituation. Principal component analysis showed that ambulatory and vertical measurements of SPA describe different dimensions of the rodent's SPA behavior. Smaller testing chambers and a sensory attenuation cubicle around the chamber reduced SPA. SPA varies between rodents purchased from different vendors. Radiotelemetry and infrared photobeams differ in their sensitivity to detect phenotypic differences in SPA and exploratory activity. These data highlight methodological considerations in rodent SPA measurement and a need to standardize SPA methodology.

  1. Old World hantaviruses in rodents in New Orleans, Louisiana.

    PubMed

    Cross, Robert W; Waffa, Bradley; Freeman, Ashley; Riegel, Claudia; Moses, Lina M; Bennett, Andrew; Safronetz, David; Fischer, Elizabeth R; Feldmann, Heinz; Voss, Thomas G; Bausch, Daniel G

    2014-05-01

    Seoul virus, an Old World hantavirus, is maintained in brown rats and causes a mild form of hemorrhagic fever with renal syndrome (HFRS) in humans. We captured rodents in New Orleans, Louisiana and tested them for the presence of Old World hantaviruses by reverse transcription polymerase chain reaction (RT-PCR) with sequencing, cell culture, and electron microscopy; 6 (3.4%) of 178 rodents captured--all brown rats--were positive for a Seoul virus variant previously coined Tchoupitoulas virus, which was noted in rodents in New Orleans in the 1980s. The finding of Tchoupitoulas virus in New Orleans over 25 years since its first discovery suggests stable endemicity in the city. Although the degree to which this virus causes human infection and disease remains unknown, repeated demonstration of Seoul virus in rodent populations, recent cases of laboratory-confirmed HFRS in some US cities, and a possible link with hypertensive renal disease warrant additional investigation in both rodents and humans.

  2. Rodent models of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis.

    PubMed

    Imajo, Kento; Yoneda, Masato; Kessoku, Takaomi; Ogawa, Yuji; Maeda, Shin; Sumida, Yoshio; Hyogo, Hideyuki; Eguchi, Yuichiro; Wada, Koichiro; Nakajima, Atsushi

    2013-11-04

    Research in nonalcoholic fatty liver disease (NAFLD), including nonalcoholic steatohepatitis (NASH), has been limited by the availability of suitable models for this disease. A number of rodent models have been described in which the relevant liver pathology develops in an appropriate metabolic context. These models are promising tools for researchers investigating one of the key issues of NASH: not so much why steatosis occurs, but what causes the transition from simple steatosis to the inflammatory, progressive fibrosing condition of steatohepatitis. The different rodent models can be classified into two large groups. The first includes models in which the disease is acquired after dietary or pharmacological manipulation, and the second, genetically modified models in which liver disease develops spontaneously. To date, no single rodent model has encompassed the full spectrum of human disease progression, but individual models can imitate particular characteristics of human disease. Therefore, it is important that researchers choose the appropriate rodent models. The purpose of the present review is to discuss the metabolic abnormalities present in the currently available rodent models of NAFLD, summarizing the strengths and weaknesses of the established models and the key findings that have furthered our understanding of the disease's pathogenesis.

  3. Public health importance of rodents in South America

    PubMed Central

    Mackenzie, R. B.

    1972-01-01

    Indigenous South American rodents are abundant, varied, and adaptable, and occupy most of the available natural habitats. Knowledge of their taxonomy and biology is generally superficial. Near human habitations the introduced Rattus and Mus are common and their contacts with man are often close. Cities in South America are expanding to keep pace with increases in the human population and hitherto virgin land is being settled or cleared for food production. Thus domestic rodents are brought into contact with indigenous species and the inevitable exchange of parasites may then produce unpredictable threats to human health. The role of both wild and domestic rodents in the transmission of certain infectious diseases, such as plague, sylvatic Venezuelan encephalitis, South American haemorrhagic fevers, murine typhus, and cutaneous leishmaniasis, is well established. The involvement of rodents in some other diseases, such as leptospirosis, American trypanosomiasis, South American hydatid disease, and vesicular stomatitis, is less well understood. In certain other infections, including bartonellosis and the South American spotted fevers, a wild rodent reservoir is inferred but not yet identified. PMID:4539412

  4. Developmental genetics in emerging rodent models: case studies and perspectives.

    PubMed

    Mallarino, Ricardo; Hoekstra, Hopi E; Manceau, Marie

    2016-08-01

    For decades, mammalian developmental genetic studies have focused almost entirely on two laboratory models: Mus and Rattus, species that breed readily in the laboratory and for which a wealth of molecular and genetic resources exist. These species alone, however, do not capture the remarkable diversity of morphological, behavioural and physiological traits seen across rodents, a group that represents >40% of all mammal species. Due to new advances in molecular tools and genomic technologies, studying the developmental events underlying natural variation in a wide range of species for a wide range of traits has become increasingly feasible. Here we review several recent studies and discuss how they not only provided technical resources for newly emerging rodent models in developmental genetics but also are instrumental in further encouraging scientists, from a wide range of research fields, to capitalize on the great diversity in development that has evolved among rodents.

  5. Skin diseases of rodents and small exotic mammals.

    PubMed

    Ellis, C; Mori, M

    2001-05-01

    Small exotic mammals and rodents are becoming popular pets in the United States. Like most other exotics, the popularity of these animals has vastly preceded the accumulation of practical husbandry and veterinary information available about them. Several dermatologic conditions have been described in most rodents and small exotic mammals; however, the practitioner can assume that more exist that have not yet been diagnosed or documented. It is not unreasonable to assume that rodents and small exotic mammals could be affected by many of the same dermatologic conditions well described in other animals. Veterinarians are encouraged always to apply the same diagnostic protocols used to work up skin problems in dogs and cats when presented with an exotic pet with a dermatologic disease.

  6. Strontium biokinetic model for mouse-like rodent.

    PubMed

    Malinovsky, Georgy; Yarmoshenko, Ilia; Zhukovsky, Michael; Starichenko, Vera; Modorov, Makar

    2013-04-01

    Model describing the biokinetics of strontium for murine rodent is suggested. The model represents modification of the ICRP model for reference human with reduced number of compartments: Blood, Gastrointestinal tract, Soft tissues, Skeleton, Urinary bladder. To estimate transfer rates of the model the published experimental data on strontium retention in body of laboratory and wild mice were analyzed. A set of eleven transfer rates suggested for the strontium biokinetic model for murine rodent satisfactorily describes both the laboratory experiments (relative standard error of 9.5%) and data on radiostrontium content available for wild animals. Application of the model allows estimation of strontium distribution by organs and tissues both in the cases of acute and chronic exposure with assessment of strontium activity in organs with time since beginning of exposure. The developed strontium biokinetic model will be used for internal dose assessment for murine rodents inhabiting East-Ural Radioactive Trace, where (90)Sr intake is a significant source of contemporary internal exposure.

  7. Can shrub cover increase predation risk for a desert rodent?

    USGS Publications Warehouse

    Schooley, R.L.; Sharpe, Peter B.

    1996-01-01

    Previous research indicates that predation risk may influence activity patterns, habitat partitioning, and community structure of nocturnal desert rodents. Shrub microhabitat is typically considered safer than open microhabitat for these small mammals. We investigated predation risk for Townsend's ground squirrels (Spermophilus townsendii), which are diurnal desert rodents that detect predators visually and use burrows for refuge. Our results suggested that shrub cover may increase risk for these squirrels by decreasing their ability to escape from predators. Our field experiment indicated that running speeds of juvenile squirrels were lower in shrub (Ceratoides lanata) habitat than in open areas. Shrub cover was also associated with shorter predator-detection distances (mammalian and avian) and fewer refuges (burrow entrances per hectare) than in open areas in one year but not in another. Our study demonstrated that the visual and locomotive obstruction of vegetative cover may increase predation risk for diurnal desert rodents and that elements of habitat-dependent risk may be temporally dynamic.

  8. Colonisation and shedding of Lawsonia intracellularis in experimentally inoculated rodents and in wild rodents on pig farms.

    PubMed

    Collins, A M; Fell, S; Pearson, H; Toribio, J-A

    2011-06-02

    Lawsonia intracellularis is an intracellular bacterium causing proliferative enteropathy in various animal species, and is considered an economically important pathogen of pigs. Rats and mice have been implicated as external vectors for a wide range of pig pathogens, including L. intracellularis. Previous studies have demonstrated L. intracellularis infection and proliferative enteropathy in rodents, but did not show the duration of shedding or the number of L. intracellularis shed by infected rodents, and therefore the infection risk that rodents pose to pigs. In this study, the number of L. intracellularis shed in the faeces and intestinal mucosa of wild rats trapped on pig farms was determined by a quantitative real time polymerase chain reaction assay. The prevalence of L. intracellularis in wild rats trapped on pig farms with endemic proliferative enteropathy (PE) was very high (≥ 70.6%), and large numbers of L. intracellularis were shed (10(10)/g of faeces) in a small proportion of wild rats. The duration of colonisation in laboratory rats and mice challenged with porcine isolates of L. intracellularis was also shown. Faecal shedding of L. intracellularis persisted for 14-21 days in rats and mice that were mildly affected with histological lesions of PE. The humoral immune response to L. intracellularis persisted for 40 days in both species. This study demonstrates that rodents may be an important reservoir of L. intracellularis on piggeries, and hence rodent control is important in disease eradication programs on pig farms.

  9. Synanthropic rodents as possible reservoirs of shigatoxigenic Escherichia coli strains

    PubMed Central

    Blanco Crivelli, Ximena; Rumi, María V.; Carfagnini, Julio C.; Degregorio, Osvaldo; Bentancor, Adriana B.

    2012-01-01

    Shigatoxigenic Escherichia coli (STEC) strains are worldwide zoonotic pathogen responsible for different cases of human disease including hemolytic uremic syndrome (HUS). Transmission of STEC to humans occurs through the consumption of food and water contaminated by faeces of carriers and by person-to-person contact. The objective of this study was two-fold: (1) to investigate whether synanthropic rodents are possible reservoirs of STEC in the urban area and (2) whether a particular genus out of synanthropic rodent is the principal carrier of STEC. One hundred and forty-five rodents were captured in Buenos Aires City. Screening for stx1/stx2 and rfbO157 was done by PCR from the confluence zone. STEC isolates were further characterized with biochemical tests by standard methods. Additional virulence factors (eae, ehxA, and saa) were also determined by PCR. Forty-one of the rodents were necropsied and sample of kidney and small and large intestine were taken for histopathological diagnosis. The samples sections were stained with hematoxylin-eosin, and observed by light microscopy to evaluate the systemic involvement of these species in natural infections. STEC was isolated from seven out of 27 suspect animals at screening. The following genotypes were found in the STEC strains: stx1/stx2/ehxA (1), stx2 (4), stx2/ehxA (1), stx2/ehxA/eae (1). Neither gross nor microscopic lesions compatible with those produced by Shiga toxin were observed in the studied organs of necropsied rodents. The bivariate analysis including the 145 rodent's data showed that the isolation of STEC is associated positively to Rattus genus. This synanthropic species may play a role in the transmissibility of the agent thus being a risk to the susceptible population. Their control should be included specifically in actions to dismiss the contamination of food and water by STEC in the urban area, as additional strategies for epidemiological control. PMID:23125967

  10. Are Synonymous Sites in Primates and Rodents Functionally Constrained?

    PubMed

    Price, Nicholas; Graur, Dan

    2016-01-01

    It has been claimed that synonymous sites in mammals are under selective constraint. Furthermore, in many studies the selective constraint at such sites in primates was claimed to be more stringent than that in rodents. Given the larger effective population sizes in rodents than in primates, the theoretical expectation is that selection in rodents would be more effective than that in primates. To resolve this contradiction between expectations and observations, we used processed pseudogenes as a model for strict neutral evolution, and estimated selective constraint on synonymous sites using the rate of substitution at pseudosynonymous and pseudononsynonymous sites in pseudogenes as the neutral expectation. After controlling for the effects of GC content, our results were similar to those from previous studies, i.e., synonymous sites in primates exhibited evidence for higher selective constraint that those in rodents. Specifically, our results indicated that in primates up to 24% of synonymous sites could be under purifying selection, while in rodents synonymous sites evolved neutrally. To further control for shifts in GC content, we estimated selective constraint at fourfold degenerate sites using a maximum parsimony approach. This allowed us to estimate selective constraint using mutational patterns that cause a shift in GC content (GT ↔ TG, CT ↔ TC, GA ↔ AG, and CA ↔ AC) and ones that do not (AT ↔ TA and CG ↔ GC). Using this approach, we found that synonymous sites evolve neutrally in both primates and rodents. Apparent deviations from neutrality were caused by a higher rate of C → A and C → T mutations in pseudogenes. Such differences are most likely caused by the shift in GC content experienced by pseudogenes. We conclude that previous estimates according to which 20-40% of synonymous sites in primates were under selective constraint were most likely artifacts of the biased pattern of mutation.

  11. Australian helminths in Australian rodents: an issue of biodiversity.

    PubMed

    Warner, L R

    1998-06-01

    The Australian public as well as Australian funding bodies are generally unsympathetic to native murids, rats and mice, in spite of the fact that 36% have either become extinct or critically endangered since European settlement. The endemic Australian parasites of these rats and mice have been even less sympathetically regarded. Prior to 1958 very little work was carried out on the helminths of Australian rodents and little more is known today. Records are known from only 28% of the extant host species, comprising some 109 species of helminth identified at least to generic level. The rodents invaded Australia from the north, perhaps through New Guinea in at least two separate waves, 5-8 then about 1 million years ago. The parasites they brought with them have adapted and speciated and there has been some host switching between rodent groups and between rodents and the Australian marsupials. This is illustrated particularly in the Trichostrongyloidea. The origins of the rodents from Southeast Asia down the Indonesian island chain are reflected in the presence of the nematode genus Tikusnema in both Australia and Indonesia, and Cyclodontostomum purvisi across Southeast Asia and into New Guinea. Hydromys chrysogaster, the Australian water-rat, illustrates how the biogeographical influences of the host's distribution and lifestyle can affect its parasite fauna. Most of the research to date is merely indicative of where more data are needed. The links between Australian and New Guinean helminth fauna, as well as the links between rodent and marsupial hosts and their fauna, cannot be determined without further research.

  12. Multiple infections of rodents with zoonotic pathogens in Austria.

    PubMed

    Schmidt, Sabrina; Essbauer, Sandra S; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald; Ulrich, Rainer G

    2014-07-01

    Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host-pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans.

  13. Multiple Infections of Rodents with Zoonotic Pathogens in Austria

    PubMed Central

    Schmidt, Sabrina; Essbauer, Sandra S.; Mayer-Scholl, Anne; Poppert, Sven; Schmidt-Chanasit, Jonas; Klempa, Boris; Henning, Klaus; Schares, Gereon; Groschup, Martin H.; Spitzenberger, Friederike; Richter, Dania; Heckel, Gerald

    2014-01-01

    Abstract Rodents are important reservoirs for a large number of zoonotic pathogens. We examined the occurrence of 11 viral, bacterial, and parasitic agents in rodent populations in Austria, including three different hantaviruses, lymphocytic choriomeningitis virus, orthopox virus, Leptospira spp., Borrelia spp., Rickettsia spp., Bartonella spp., Coxiella burnetii, and Toxoplasma gondii. In 2008, 110 rodents of four species (40 Clethrionomys glareolus, 29 Apodemus flavicollis, 26 Apodemus sylvaticus, and 15 Microtus arvalis) were trapped at two rural sites in Lower Austria. Chest cavity fluid and samples of lung, spleen, kidney, liver, brain, and ear pinna skin were collected. We screened selected tissue samples for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, Leptospira, Borrelia, Rickettsia, Bartonella spp., C. burnetii, and T. gondii by RT-PCR/PCR and detected nucleic acids of Tula hantavirus, Leptospira spp., Borrelia afzelii, Rickettsia spp., and different Bartonella species. Serological investigations were performed for hantaviruses, lymphocytic choriomeningitis virus, orthopox viruses, and Rickettsia spp. Here, Dobrava-Belgrade hantavirus-, Tula hantavirus-, lymphocytic choriomeningitis virus-, orthopox virus-, and rickettsia-specific antibodies were demonstrated. Puumala hantavirus, C. burnetii, and T. gondii were neither detected by RT-PCR/PCR nor by serological methods. In addition, multiple infections with up to three pathogens were shown in nine animals of three rodent species from different trapping sites. In conclusion, these results show that rodents in Austria may host multiple zoonotic pathogens. Our observation raises important questions regarding the interactions of different pathogens in the host, the countermeasures of the host's immune system, the impact of the host–pathogen interaction on the fitness of the host, and the spread of infectious agents among wild rodents and from those to other animals or humans. PMID

  14. Social and cultural dimensions of rodent pest management.

    PubMed

    Palis, Florencia G; Singleton, Grant; Sumalde, Zenaida; Hossain, Mahabub

    2007-09-01

    Rice production in Vietnam is threatened by rodent pests, with a significant increase in impact reported from 1990 through to the early 21st century. Pre-harvest rice losses are typically 5-10%, with losses of >20% occurring in some years in some regions. Farmers' rodent control practices are generally reactive and rely essentially on chemical and physical methods. Ecologically-based rodent pest management (EBRM) was developed in the late 1990s to manage rodents in rice-based farming systems in Vietnam and other parts of South-East Asia. EBRM combines both cultural and physical rodent management practices such as synchrony of cropping, short 2-week rat campaigns at key periods in key habitats, increasing general hygiene around villages, and use of a community trap-barrier system. Although EBRM has been reported to be economically profitable, the successful adoption of this set of technologies requires community participation. In this paper we address issues relating to the adoption and sustainability of EBRM in lowland irrigated rice fields in the Mekong Delta in Vietnam. We particularly explore the social and cultural mechanisms involved in maintaining community participation to further understand the conditions under which EBRM works and does not work. Positive indications of sustained use of community-based EBRM include: a policy pronouncement from the prime minister directing the use of integrated rodent management; the use of existing cooperatives for developing community actions; budgetary allocation from provincial and local governments; diffusion of EBRM to provinces in the south and north that are not involved in farmer participatory field trials; and the adoption of EBRM by a non-governmental organization, World Vision Vietnam, in their area-development programs.

  15. Excitation-inhibition discoordination in rodent models of mental disorders

    PubMed Central

    Fenton, André A.

    2015-01-01

    Animal models of mental illness provide a foundation for evaluating hypotheses for the mechanistic causes of mental illness. Neurophysiological investigations of neural network activity in rodent models of mental dysfunction are reviewed from the conceptual framework of the discoordination hypothesis, which asserts that failures of neural coordination cause cognitive deficits in the judicious processing and use of information. Abnormal dynamic coordination of excitatory and inhibitory neural discharge in pharmacological and genetic rodent models support the discoordination hypothesis. These observations suggest excitation-inhibition discoordination and aberrant neural circuit dynamics as causes of cognitive impairment as well as therapeutic targets for cognition-promoting treatments. PMID:25895430

  16. Museum specimen data predict crop damage by tropical rodents

    PubMed Central

    Sánchez-Cordero, Víctor; Martínez-Meyer, Enrique

    2000-01-01

    Museum collections constitute a massive store of information on biological diversity. We used museum specimen data to generate ecological niche models that provide predictions of geographic distributions of native rodent pest species and agricultural census data that summarize the geographic distribution of nine crops in the state of Veracruz, Mexico, as well as crop losses between planting and harvest. Herein, we show that crop damage is related significantly to the predicted presence of rodent species for seven of nine crops. Museum collections may thus provide important baseline information for designing land-use and agricultural pest-management programs. PMID:10860973

  17. Discovery of Novel Alphacoronaviruses in European Rodents and Shrews.

    PubMed

    Tsoleridis, Theocharis; Onianwa, Okechukwu; Horncastle, Emma; Dayman, Emma; Zhu, Miaoran; Danjittrong, Taechasit; Wachtl, Marta; Behnke, Jerzy M; Chapman, Sarah; Strong, Victoria; Dobbs, Phillipa; Ball, Jonathan K; Tarlinton, Rachael E; McClure, C Patrick

    2016-03-18

    Eight hundred and thirteen European rodents and shrews encompassing seven different species were screened for alphacoronaviruses using PCR detection. Novel alphacoronaviruses were detected in the species Rattus norvegicus, Microtus agrestis, Sorex araneus and Myodes glareolus. These, together with the recently described Lucheng virus found in China, form a distinct rodent/shrew-specific clade within the coronavirus phylogeny. Across a highly conserved region of the viral polymerase gene, the new members of this clade were up to 22% dissimilar at the nucleotide level to the previously described Lucheng virus. As such they might represent distinct species of alphacoronaviruses. These data greatly extend our knowledge of wildlife reservoirs of alphacoronaviruses.

  18. Experimental infection of Rio Mamore hantavirus in Sigmodontinae rodents

    PubMed Central

    de Souza, William Marciel; Machado, Alex Martins; Figueiredo, Luiz Tadeu Moraes

    2016-01-01

    This study shows an experimental spillover infection ofSigmodontinae rodents with Rio Mamore hantavirus (RIOMV).Necromys lasiurus and Akodon sp were infected with 103 RNA copies of RIOMV by intraperitoneal administration. The viral genome was detected in heart, lung, and kidney tissues 18 days after infection (ai), and viral excretion in urine and faeces began at four and six ai, respectively. These results reveal that urine and faeces of infected rodents contain the virus for at least 18 days. It is possible that inhaled aerosols of these excreta could transmit hantavirus to humans and other animals. PMID:27223653

  19. Rodent community landscape ecology in grassland-shrubland ecotones and gradients in the Chihuahuan Desert

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is believed that the abundance and diversity of Chihuahuan Desert rodents increases with shrub encroachment accompanying desertification although grassland specialist species decline with loss of perennial grasses. It has been reported, however, that rodent population responses to spatial variati...

  20. Lassa serology in natural populations of rodents and horizontal transmission.

    PubMed

    Fichet-Calvet, Elisabeth; Becker-Ziaja, Beate; Koivogui, Lamine; Günther, Stephan

    2014-09-01

    Lassa virus causes hemorrhagic fever in West Africa. Previously, we demonstrated by PCR screening that only the multimammate mouse, Mastomys natalensis, hosts Lassa virus in Guinea. In the present study, we used the same specimen collection from 17 villages in Coastal, Upper, and Forest Guinea to investigate the Lassa virus serology in the rodent population. The aim was to determine the dynamics of antibody development in M. natalensis and to detect potential spillover infections in other rodent species. Immunoglobulin G (IgG) antibody screening was performed using the indirect immunofluorescence assay with the Guinean Lassa virus strain Bantou 289 as antigen. The overall seroprevalence was 8% (129/1551) with the following rodents testing positive: 109 M. natalensis, seven Mastomys erythroleucus, four Lemniscomys striatus, four Praomys daltoni, three Mus minutoides, and two Praomys rostratus. Nearly all of them (122/129) originated from Bantou, Tanganya, and Gbetaya, where Lassa virus is highly endemic in M. natalensis. The antibody seroprevalence in M. natalensis from this high-endemic area (27%; 108/396) depended on the village, habitat, host age, and host abundance. A main positive factor was age; the maximum seroprevalence reached 50% in older animals. Our data fit with a model implicating that most M. natalensis rodents become horizontally infected, clear the virus within a period significantly shorter than their life span, and develop antibodies. In addition, the detection of antibodies in other species trapped in the habitats of M. natalensis suggests spillover infections.

  1. Neural representation of spatial topology in the rodent hippocampus.

    PubMed

    Chen, Zhe; Gomperts, Stephen N; Yamamoto, Jun; Wilson, Matthew A

    2014-01-01

    Pyramidal cells in the rodent hippocampus often exhibit clear spatial tuning in navigation. Although it has been long suggested that pyramidal cell activity may underlie a topological code rather than a topographic code, it remains unclear whether an abstract spatial topology can be encoded in the ensemble spiking activity of hippocampal place cells. Using a statistical approach developed previously, we investigate this question and related issues in greater detail. We recorded ensembles of hippocampal neurons as rodents freely foraged in one- and two-dimensional spatial environments and used a "decode-to-uncover" strategy to examine the temporally structured patterns embedded in the ensemble spiking activity in the absence of observed spatial correlates during periods of rodent navigation or awake immobility. Specifically, the spatial environment was represented by a finite discrete state space. Trajectories across spatial locations ("states") were associated with consistent hippocampal ensemble spiking patterns, which were characterized by a state transition matrix. From this state transition matrix, we inferred a topology graph that defined the connectivity in the state space. In both one- and two-dimensional environments, the extracted behavior patterns from the rodent hippocampal population codes were compared against randomly shuffled spike data. In contrast to a topographic code, our results support the efficiency of topological coding in the presence of sparse sample size and fuzzy space mapping. This computational approach allows us to quantify the variability of ensemble spiking activity, examine hippocampal population codes during off-line states, and quantify the topological complexity of the environment.

  2. An expanded clade of rodent Trim5 genes.

    PubMed

    Tareen, Semih U; Sawyer, Sara L; Malik, Harmit S; Emerman, Michael

    2009-03-15

    Trim5alpha from primates (including humans), cows, and rabbits has been shown to be an active antiviral host gene that acts against a range of retroviruses. Although this suggests that Trim5alpha may be a common antiviral restriction factor among mammals, the status of Trim5 genes in rodents has been unclear. Using genomic and phylogenetic analyses, we describe an expanded paralogous cluster of at least eight Trim5-like genes in mice (including the previously described Trim12 and Trim30 genes), and three Trim5-like genes in rats. Our characterization of the rodent Trim5 locus, and comparison to the Trim5 locus in humans, cows, and rabbits, indicates that Trim5 has undergone independent evolutionary expansions within species. Evolutionary analysis shows that rodent Trim5 genes have evolved under positive selection, suggesting evolutionary conflicts consistent with important antiviral function. Sampling six rodent Trim5 genes failed to reveal antiviral activities against a set of eight retroviral challenges, although we predict that such activities exist.

  3. Astronaut Norman Thagard changes tray in RAHF for rodents

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Astronaut Norman Thagard changes a tray in the research animal holding facility (RAHF) for rodents at the Ames double rack facility aboard the Spacelab 3 science module in the cargo bay of the shuttle Challenger. Lending a hand is payload specialist Lodewijk van den Berg. Both men are wearing protective clothing and surgical masks for this procedure.

  4. Recent and widespread rapid morphological change in rodents.

    PubMed

    Pergams, Oliver R W; Lawler, Joshua J

    2009-07-31

    In general, rapid morphological change in mammals has been infrequently documented. Examples that do exist are almost exclusively of rodents on islands. Such changes are usually attributed to selective release or founder events related to restricted gene flow in island settings. Here we document rapid morphological changes in rodents in 20 of 28 museum series collected on four continents, including 15 of 23 mainland sites. Approximately 17,000 measurements were taken of 1302 rodents. Trends included both increases and decreases in the 15 morphological traits measured, but slightly more trends were towards larger size. Generalized linear models indicated that changes in several of the individual morphological traits were associated with changes in human population density, current temperature gradients, and/or trends in temperature and precipitation. When we restricted these analyses to samples taken in the US (where data on human population trends were presumed to be more accurate), we found changes in two additional traits to be positively correlated with changes in human population density. Principle component analysis revealed general trends in cranial and external size, but these general trends were uncorrelated with climate or human population density. Our results indicate that over the last 100+ years, rapid morphological change in rodents has occurred quite frequently, and that these changes have taken place on the mainland as well as on islands. Our results also suggest that these changes may be driven, at least in part, by human population growth and climate change.

  5. CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS

    EPA Science Inventory


    CONCENTRATED AMBIENT PARTICULATE STUDIES IN HEALTHY AND COMPROMISED RODENTS. WP Watkinson1, LB Wichers2, JP Nolan1, DW Winsett1, UP Kodavanti1, MCJ Schladweiler1, LC Walsh1, ER Lappi1, D Terrell1, R Slade1, AD Ledbetter1, and DL Costa1. 1USEPA, ORD/NHEERL/ETD/PTB, RTP, NC, US...

  6. Response of brown treesnakes to reduction of their rodent prey

    USGS Publications Warehouse

    Gragg, J.E.; Rodda, G.H.; Savidge, J.A.; White, Gary C.; Dean-Bradley, K.; Ellingson, A.R.

    2007-01-01

    Trapping brown treesnakes (Boiga irregularis; BTS) with live-mouse (Mus domesticus) lures is the principal control technique for this invasive species on Guam. Lure-based trapping is also used on other islands as a precaution against undetected arrivals and in response to verified BTS sightings. However, the effectiveness of lure-based trapping on other islands is questionable, as it has yielded no BTS despite other evidence of their presence. Some evidence suggests that high rodent numbers may interfere with BTS control. To test the relationship between rodent abundance and snake trappability, we conducted a controlled, replicated field experiment incorporating a rodenticide treatment during a BTS mark-recapture study. Using open population modeling in Program MARK, we estimated BTS apparent survival and recapture probabilities. Rodent reduction increased BTS recapture probabilities by 52-65% in 2002 and 22-36% in 2003, and it decreased apparent survival by <1% both years. This appears to be the first published instance of manipulating wild prey to influence snake behavior. Rodent reduction may enhance detection and control of BTS with traps on Guam and other islands. It may also amplify the effectiveness of oral toxicants against BTS.

  7. Optimizing cardiovascular benefits of exercise: a review of rodent models.

    PubMed

    Davis, Brittany; Moriguchi, Takeshi; Sumpio, Bauer

    2013-03-01

    Although research unanimously maintains that exercise can ward off cardiovascular disease (CVD), the optimal type, duration, intensity, and combination of forms are yet not clear. In our review of existing rodent-based studies on exercise and cardiovascular health, we attempt to find the optimal forms, intensities, and durations of exercise. Using Scopus and Medline, a literature review of English language comparative journal studies of cardiovascular benefits and exercise was performed. This review examines the existing literature on rodent models of aerobic, anaerobic, and power exercise and compares the benefits of various training forms, intensities, and durations. The rodent studies reviewed in this article correlate with reports on human subjects that suggest regular aerobic exercise can improve cardiac and vascular structure and function, as well as lipid profiles, and reduce the risk of CVD. Findings demonstrate an abundance of rodent-based aerobic studies, but a lack of anaerobic and power forms of exercise, as well as comparisons of these three components of exercise. Thus, further studies must be conducted to determine a truly optimal regimen for cardiovascular health.

  8. 40 CFR 798.5460 - Rodent heritable translocation assays.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Rodent heritable translocation assays. 798.5460 Section 798.5460 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...) Species. The mouse is the species generally used, and is recommended. (ii) Age. Healthy sexually...

  9. Assessment of the use of selected rodents in ecological monitoring

    NASA Astrophysics Data System (ADS)

    Douglass, Richard J.

    1989-05-01

    Rodents can be useful in detecting environmental impacts because they are easy to study (easy to capture and handle), they can occur in densities adequate for statistical analysis, and they are ecologically important. In this study the usefulness of rodent populations for ecological monitoring was investigated by examining the effect of variation on the possibility of detecting differences among populations of rodents on 10 trapping grids. The effects of sampling frequencies and dispersal on detecting differences in population parameters among grids was also investigated, as was the possibility of inferring population parameters from correlations with habitat data. Statistically significant differences as small as 4.3 Peromyscus maniculatus/ha were detected between grids. Of 10 populations, this comprised 12% of the highest-density population and 44% of the lowest-density population. Smaller and more differences among grids were found by examining only animals surviving from previous months. Dispersal confounds detection of direct impacts to populations, especially during the breeding season. Infrequent sampling fails to detect impacts that occur between sampling periods and will indicate impacts when observed changes result from natural variation. Correlations between population parameters and habitat variables exist but should only be used in predicting, not measuring, impacts. It is concluded that some rodent populations can be used in ecological monitoring. However, intensive sampling is required to account for variation and dispersal.

  10. Juquitiba-like Hantavirus from 2 Nonrelated Rodent Species, Uruguay

    PubMed Central

    Delfraro, Adriana; Tomé, Lorena; D’Elía, Guillermo; Clara, Mario; Achával, Federico; Russi, José C.

    2008-01-01

    Serologic and genetic analyses indicate that a Juquitiba-like hantavirus circulates in Maldonado, Uruguay. This virus is carried by 2 rodent species, Oligoryzomys nigripes and Oxymycterus nasutus. The same hantavirus in 2 nonrelated species can be explained by a spillover infection or a host-switching event. PMID:18760017

  11. PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS

    EPA Science Inventory

    PERFLUOROOCTANE SULFONATE (PFOS) DISRUPTS THE THYROID STATUS IN LABORATORY RODENTS. C. Lau, J.R. Thibodeaux, R.G. Hanson, B.E. Gray and J.M. Rogers. Reprod. Tox. Div. NHEERL, US EPA, Research Triangle Park, NC.

    PFOS is an environmental contaminant ubiquitously found in h...

  12. Evolution of the Genomic Recombination Rate in Murid Rodents

    PubMed Central

    Dumont, Beth L.; Payseur, Bret A.

    2011-01-01

    Although very closely related species can differ in their fine-scale patterns of recombination hotspots, variation in the average genomic recombination rate among recently diverged taxa has rarely been surveyed. We measured recombination rates in eight species that collectively represent several temporal scales of divergence within a single rodent family, Muridae. We used a cytological approach that enables in situ visualization of crossovers at meiosis to quantify recombination rates in multiple males from each rodent group. We uncovered large differences in genomic recombination rate between rodent species, which were independent of karyotypic variation. The divergence in genomic recombination rate that we document is not proportional to DNA sequence divergence, suggesting that recombination has evolved at variable rates along the murid phylogeny. Additionally, we document significant variation in genomic recombination rate both within and between subspecies of house mice. Recombination rates estimated in F1 hybrids reveal evidence for sex-linked loci contributing to the evolution of recombination in house mice. Our results provide one of the first detailed portraits of genomic-scale recombination rate variation within a single mammalian family and demonstrate that the low recombination rates in laboratory mice and rats reflect a more general reduction in recombination rate across murid rodents. PMID:21149647

  13. Complexity in rodent community responses to grassland-shrubland transitions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is believed that the abundance and diversity of Chihuahuan Desert rodents increases with shrub encroachment accompanying desertification although grassland specialist species decline with loss of perennial grasses. It has been reported, however, that a suite of biotic-abiotic interactions may inf...

  14. Andes Hantavirus Variant in Rodents, Southern Amazon Basin, Peru

    PubMed Central

    Tokarz, Rafal; Ghersi, Bruno M.; Salmon-Mulanovich, Gabriela; Guezala, M. Claudia; Albujar, Christian; Mendoza, A. Patricia; Tinoco, Yeny O.; Cruz, Christopher; Silva, Maria; Vasquez, Alicia; Pacheco, Víctor; Ströher, Ute; Guerrero, Lisa Wiggleton; Cannon, Deborah; Nichol, Stuart T.; Hirschberg, David L.; Lipkin, W. Ian; Bausch, Daniel G.; Montgomery, Joel M.

    2014-01-01

    We investigated hantaviruses in rodents in the southern Amazon Basin of Peru and identified an Andes virus variant from Neacomys spinosus mice. This finding extends the known range of this virus in South America and the range of recognized hantaviruses in Peru. Further studies of the epizoology of hantaviruses in this region are warranted. PMID:24447689

  15. The rodent hippocampus is essential for nonspatial object memory.

    PubMed

    Cohen, Sarah J; Munchow, Alcira H; Rios, Lisa M; Zhang, Gongliang; Asgeirsdóttir, Herborg N; Stackman, Robert W

    2013-09-09

    Elucidating the role of the rodent hippocampus in object recognition memory is critical for establishing the appropriateness of rodents as models of human memory and for their use in the development of memory disorder treatments. In mammals, spatial memory and nonspatial memory depend upon the hippocampus and associated medial temporal lobe (MTL) structures. Although well established in humans, the role of the rodent hippocampus in object memory remains highly debated due to conflicting findings across temporary and permanent hippocampal lesion studies and evidence that the perirhinal cortex may support object memory. In the current studies, we used intrahippocampal muscimol microinfusions to transiently inactivate the male C57BL/6J mouse hippocampus at distinct stages during the novel object recognition (NOR) task: during object memory encoding and consolidation, just consolidation, and/or retrieval. We also assessed the effect of temporary hippocampal inactivation when objects were presented in different contexts, thus eliminating the spatial or contextual components of the task. Lastly, we assessed extracellular dorsal hippocampal glutamate efflux and firing properties of hippocampal neurons while mice performed the NOR task. Our results reveal a clear and compelling role of the rodent hippocampus in nonspatial object memory.

  16. Leptospira spp. in rodents and shrews in Germany.

    PubMed

    Mayer-Scholl, Anne; Hammerl, Jens Andre; Schmidt, Sabrina; Ulrich, Rainer G; Pfeffer, Martin; Woll, Dietlinde; Scholz, Holger C; Thomas, Astrid; Nöckler, Karsten

    2014-07-24

    Leptospirosis is an acute, febrile disease occurring in humans and animals worldwide. Leptospira spp. are usually transmitted through direct or indirect contact with the urine of infected reservoir animals. Among wildlife species, rodents act as the most important reservoir for both human and animal infection. To gain a better understanding of the occurrence and distribution of pathogenic leptospires in rodent and shrew populations in Germany, kidney specimens of 2973 animals from 11 of the 16 federal states were examined by PCR. Rodent species captured included five murine species (family Muridae), six vole species (family Cricetidae) and six shrew species (family Soricidae). The most abundantly trapped animals were representatives of the rodent species Apodemus flavicollis, Clethrionomys glareolus and Microtus agrestis. Leptospiral DNA was amplified in 10% of all animals originating from eight of the 11 federal states. The highest carrier rate was found in Microtus spp. (13%), followed by Apodemus spp. (11%) and Clethrionomys spp. (6%). The most common Leptospira genomospecies determined by duplex PCR was L. kirschneri, followed by L. interrogans and L. borgpetersenii; all identified by single locus sequence typing (SLST). Representatives of the shrew species were also carriers of Leptospira spp. In 20% of Crocidura spp. and 6% of the Sorex spp. leptospiral DNA was detected. Here, only the pathogenic genomospecies L. kirschneri was identified.

  17. Andes hantavirus variant in rodents, southern Amazon Basin, Peru.

    PubMed

    Razuri, Hugo; Tokarz, Rafal; Ghersi, Bruno M; Salmon-Mulanovich, Gabriela; Guezala, M Claudia; Albujar, Christian; Mendoza, A Patricia; Tinoco, Yeny O; Cruz, Christopher; Silva, Maria; Vasquez, Alicia; Pacheco, Víctor; Ströher, Ute; Guerrero, Lisa Wiggleton; Cannon, Deborah; Nichol, Stuart T; Hirschberg, David L; Lipkin, W Ian; Bausch, Daniel G; Montgomery, Joel M

    2014-02-01

    We investigated hantaviruses in rodents in the southern Amazon Basin of Peru and identified an Andes virus variant from Neacomys spinosus mice. This finding extends the known range of this virus in South America and the range of recognized hantaviruses in Peru. Further studies of the epizoology of hantaviruses in this region are warranted.

  18. Phylogeography and evolutionary history of rodent-borne hantaviruses.

    PubMed

    Souza, W M; Bello, G; Amarilla, A A; Alfonso, H L; Aquino, V H; Figueiredo, L T M

    2014-01-01

    Hantavirus (Family Bunyaviridae) are mostly associated to rodents and transmitted to man by inhalation of aerosolized infected excreta of these animals. The human infection by hantaviruses can lead to severe diseases such as hemorrhagic fever with renal syndrome (HFRS) in Asia and Europe, and pulmonary syndrome (HPS) in the Americas. To determine the origin, spreading and evolutionary dynamics of rodent-borne hantaviruses, 190 sequences of nucleoprotein (N) of hantaviruses identified in 30 countries, from 1985 to 2010, were retrieved from the GenBank and analyzed using the BEAST program. Our evolutionary analysis indicates that current genetic diversity of N gene of rodent-borne hantaviruses probably was originated around 2000 years ago. Hantavirus harbored by Murinae and Arvicolinae subfamilies, probably, were originated in Asia 500-700 years ago and later spread toward Siberia, Europe, Africa and North America. Hantavirus carried by Neotominae subfamily, probably, emerged 500-600 years ago in Central America and spread toward North America. Finally, hantaviruses associated to Sigmodontinae occurred in Brazil 400 years ago and were, probably, originated from Neotominae-associated virus from northern South America. These data offer subsidies to understand the time-scale and worldwide dissemination dynamics of rodent-borne hantaviruses.

  19. Rodent Research on the International Space Station - A Look Forward

    NASA Technical Reports Server (NTRS)

    Kapusta, A. B.; Smithwick, M.; Wigley, C. L.

    2014-01-01

    Rodent Research on the International Space Station (ISS) is one of the highest priority science activities being supported by NASA and is planned for up to two flights per year. The first Rodent Research flight, Rodent Research-1 (RR-1) validates the hardware and basic science operations (dissections and tissue preservation). Subsequent flights will add new capabilities to support rodent research on the ISS. RR-1 will validate the following capabilities: animal husbandry for up to 30 days, video downlink to support animal health checks and scientific analysis, on-orbit dissections, sample preservation in RNA. Later and formalin, sample transfer from formalin to ethanol (hindlimbs), rapid cool-down and subsequent freezing at -80 of tissues and carcasses, sample return and recovery. RR-2, scheduled for SpX-6 (Winter 20142015) will add the following capabilities: animal husbandry for up to 60 days, RFID chip reader for individual animal identification, water refill and food replenishment, anesthesia and recovery, bone densitometry, blood collection (via cardiac puncture), blood separation via centrifugation, soft tissue fixation in formalin with transfer to ethanol, and delivery of injectable drugs that require frozen storage prior to use. Additional capabilities are also planned for future flights and these include but are not limited to male mice, live animal return, and the development of experiment unique equipment to support science requirements for principal investigators that are selected for flight. In addition to the hardware capabilities to support rodent research the Crew Office has implemented a training program in generic rodent skills for all USOS crew members during their pre-assignment training rotation. This class includes training in general animal handling, euthanasia, injections, and dissections. The dissection portion of this training focuses on the dissection of the spleen, liver, kidney with adrenals, brain, eyes, and hindlimbs. By achieving and

  20. Nutritional Evaluation of NASA's Rodent Food Bar Diet

    NASA Technical Reports Server (NTRS)

    Barrett, Joyce E.; Yu, Diane S.; Dalton, Bonnie P.

    2000-01-01

    Tests are being conducted on NASA's rodent Food Bar in preparation for long-term use as the rat and mouse diet aboard the International Space Station. Nutritional analyses are performed after the bars are manufactured and then repeated periodically to determine nutritional stability. The primary factors analyzed are protein, ash, fat, fiber, moisture, amino acids, fatty acids, and minerals. Nutrient levels are compared to values published in the National Research Council's dietary requirements for rodents, and also to those contained in several commonly used commercial rodent lab diets. The Food Bar is manufactured from a powdered diet to which moisture is added as it is processed through an extruder. The bars are dipped into potassium sorbate, vacuum-sealed, and irradiated. In order to determine nutrient changes during extrusion and irradiation, the powdered diet, the non-irradiated bars, and the irradiated bars are all analyzed. We have observed lower values for some nutrients (iodine, vitamin K, and iron) in the Food Bars compared with NRC requirements. Many nutrients in the Food Bars are contained at a higher level than levels in the NRC requirements. An additional factor we are investigating is the 26% moisture level in the Food Bars, which drops to about 15% within a week, compared to a stable 10% moisture in many standard lab chow diets. In addition to the nutritional analyses, the food bar is being fed to several strains of rats and mice, and feeding study and necropsy results are being observed (Barrett et al, unpublished data). Information from the nutritional analyses and from the rodent studies will enable us to recommend the formulation that will most adequately meet the rodent Food Bar requirements for long-term use aboard the Space Station.

  1. The response of human and rodent cells to hyperthermia

    SciTech Connect

    Roizin-Towle, L.; Pirro, J.P. )

    1991-04-01

    Inherent cellular radiosensitivity in vitro has been shown to be a good predictor of human tumor response in vivo. In contrast, the importance of the intrinsic thermosensitivity of normal and neoplastic human cells as a factor in the responsiveness of human tumors to adjuvant hyperthermia has never been analyzed systematically. A comparison of thermal sensitivity and thermo-radiosensitization in four rodent and eight human-derived cell lines was made in vitro. Arrhenius plots indicated that the rodent cells were more sensitive to heat killing than the human, and the break-point was 0.5 degrees C higher for the human than rodent cells. The relationship between thermal sensitivity and the interaction of heat with X rays at low doses was documented by thermal enhancement ratios (TER's). Cells received either a 1 hr exposure to 43 degrees C or a 20 minute treatment at 45 degrees C before exposure to 300 kVp X rays. Thermal enhancement ratios ranged from 1.0 to 2.7 for human cells heated at 43 degrees C and from 2.1 to 5.3 for heat exposures at 45 degrees C. Thermal enhancement ratios for rodent cells were generally 2 to 3 times higher than for human cells, because of the fact that the greater thermosensitivity of rodent cells results in a greater enhancement of radiation damage. Intrinsic thermosensitivity of human cells has relevance to the concept of thermal dose; intrinsic thermo-radiosensitization of a range of different tumor cells is useful in documenting the interactive effects of radiation combined with heat.

  2. Survey of Hymenolepis spp. in pet rodents in Italy.

    PubMed

    d'Ovidio, D; Noviello, Emilio; Pepe, P; Del Prete, L; Cringoli, G; Rinaldi, L

    2015-12-01

    We carried out the first survey of Hymenolepis spp. infection in pet rodents in Italy. Fresh fecal samples were collected from 172 pet rodents as follows: guinea pigs (Cavia porcellus; n = 60), squirrels (Callosciurus finlaysonii, Callosciurus prevosti, Tamias striatus, Tamias sibiricus, Sciurus calorinensis; n = 52), hamsters (Phodopus campbelli, Mesocricetus auratus; n = 30), chinchillas (Chinchilla lanigera; n = 13), rats (Rattus norvegicus; n = 10), and mice (Mus minutoides; n = 7). These animals were housed either in pet shops or in private houses. All fecal samples were processed using the FLOTAC pellet technique to assess the number of eggs per gram (EPG) of feces. Eggs of Hymenolepis nana were found in 24 out of 172 (13.9 %; 95 % confidence interval = 9.3-20.2 %) pet rodents. Of those rodents, 41.6 % (10/24) were rats (mean EPG = 55.7; range = 2-200), 29.2 % (7/24) mice (mean EPG = 64.5; range = 32-120), 25.0 % (6/24) were chinchillas (mean EPG = 25.5; range = 10-50), and 4.2 % (1/24) hamsters (P. campbelli) (EPG = 86.0). In addition, Hymenolepis diminuta eggs were found in 2 out of 172 (1.2 %; 95 % confidence interval = 0.2-4.6 %) rodents examined, both of which (100 %; 2/2) were pet squirrels (C. prevosti) (mean EPG = 10; range = 4-16). To the authors' knowledge, this is the first report of a natural infection of H. diminuta in pet squirrels.

  3. Bartonella species in invasive rats and indigenous rodents from Uganda.

    PubMed

    Billeter, Sarah A; Borchert, Jeff N; Atiku, Linda A; Mpanga, Joseph T; Gage, Kenneth L; Kosoy, Michael Y

    2014-03-01

    The presence of bartonellae in invasive rats (Rattus rattus) and indigenous rodents (Arvicanthis niloticus and Cricetomys gambianus) from two districts in Uganda, Arua and Zombo, was examined by PCR detection and culture. Blood from a total of 228 R. rattus, 31 A. niloticus, and 5 C. gambianus was screened using genus-specific primers targeting the 16S-23S intergenic spacer region. Furthermore, rodent blood was plated on brain heart infusion blood agar, and isolates were verified as Bartonella species using citrate synthase gene- (gltA) specific primers. One hundred and four fleas recovered from R. rattus were also tested for the presence of Bartonella species using the same gltA primer set. An overall prevalence of 1.3% (three of 228) was obtained in R. rattus, whereas 61.3% of 31 A. niloticus and 60% of five C. gambianus were positive for the presence of Bartonella species. Genotypes related to Bartonella elizabethae, a known zoonotic pathogen, were detected in three R. rattus and one C. gambianus. Bartonella strains, similar to bacteria detected in indigenous rodents from other African countries, were isolated from the blood of A. niloticus. Bartonellae, similar to bacteria initially cultured from Ornithodorus sonrai (soft tick) from Senegal, were found in two C. gambianus. Interestingly, bartonellae detected in fleas from invasive rats were similar to bacteria identified in indigenous rodents and not their rat hosts, with an overall prevalence of 6.7%. These results suggest that if fleas are competent vectors of these bartonellae, humans residing in these two districts of Uganda are potentially at greater risk for exposure to Bartonella species from native rodents than from invasive rats. The low prevalence of bartonellae in R. rattus was quite surprising, in contrast, to the detection of these organisms in a large percentage of Rattus species from other geographical areas. A possible reason for this disparity is discussed.

  4. The Touchscreen Cognitive Testing Method for Rodents: How to Get the Best out of Your Rat

    ERIC Educational Resources Information Center

    Bussey, Timothy J.; Padain, Tina L.; Skillings, Elizabeth A.; Winters, Boyer D.; Morton, A. Jennifer; Saksida, Lisa M.

    2008-01-01

    The touchscreen testing method for rodents is a computer-automated behavioral testing method that allows computer graphic stimuli to be presented to rodents and the rodents to respond to the computer screen via a nose-poke directly to the stimulus. The advantages of this method are numerous; however, a systematic study of the parameters that…

  5. Nutritional adequacy and quality control of rodent diets.

    PubMed

    Newberne, P M; Fox, J G

    1980-04-01

    One of the most often neglected variables in experimental investigations using rodents is the diet. Recent observations that diets can influence the response of a rodent to the drug, chemical or other factors under study, with biased interpretation of results, have drawn great interest. In order to be assured that the biologic response observed is a reflection of the material or condition under study, it is imperative that the diet provide essential nutrients in the proper proportions and that contaminants be kept to a minimum. Quality control is the key to these requirements; rodent diets can provide adequate nutrition, free of significant contamination. The diets which can be provided vary according to the degree of refinements; the three major types are (1) natural product, (2) semipurified and (3) chemically defined diets. Natural product diets may be open or closed formula, depending on the amount of information that the label reveals. Guaranteed analyses of proximate nutrients are provided but are of little use in assessing the nutrient value of the formulation. The National Academy of Sciences, National Research Council publications on laboratory animal nutrient requirements should be available to all investigators using experimental animals to help them evaluate the nutritional adequacy of the diets they use. Rats and mice may be considered together under some circumstances relative to crude dietary needs, but the Syrian golden hamster should be treated separately for purposes of diet. This species appears to digest foods more like a ruminant. An ideal diet for rodents is not on the horizon because of variable needs relative to different types of research and holding. Storage and shelf life of rodent diets also play important roles in providing adequate nutrition. Variations in moisture, temperature and exposure to other chemicals can affect the quality of the feed and research results. In addition, a number of chemical and biological contaminants have been

  6. [Strategies for sustainable management of commensal rodents. Definitions of control objectives at communal level].

    PubMed

    Plenge-Bönig, A; Schmolz, E

    2014-05-01

    The German Act on the Prevention and Control of Infectious Diseases in Man (Infektionsschutzgesetz, IfSG) provides a legal framework for activities and responsibilities concerning communal rodent control. However, actual governance of communal rodent control is relatively heterogeneous, as federal states (Bundesländer) have different or even no regulations for prevention and management of commensal rodent infestations (e.g. brown rats, roof rats and house mice). Control targets and control requirements are rarely precisely defined and often do not go beyond general measures and objectives. Although relevant regulations provide information about agreed preventive measures against rodents, the concept of sustainability is not expressed as such. A centrally managed database-supported municipal rodent control is a key factor for sustainability because it allows a systematic and analytical approach to identify and reduce rodent populations. The definition of control objectives and their establishment in legal decrees is mandatory for the implementation of a sustainable management strategy of rodent populations at a local level. Systematic recording of rodent infestations through municipal-operated monitoring provides the essential data foundation for a targeted rodent management which is already implemented in some German and European cities and nationwide in Denmark. A sustainable rodent management includes a more targeted rodenticide application which in the long-term will lead to an overall reduction of rodenticide use. Thus, the benefits of sustainable rodent management will be a reduction of rodenticide exposure to the environment, prevention of resistance and long-term economical savings.

  7. Perceptual Decision Making in Rodents, Monkeys, and Humans.

    PubMed

    Hanks, Timothy D; Summerfield, Christopher

    2017-01-04

    Perceptual decision making is the process by which animals detect, discriminate, and categorize information from the senses. Over the past two decades, understanding how perceptual decisions are made has become a central theme in the neurosciences. Exceptional progress has been made by recording from single neurons in the cortex of the macaque monkey and using computational models from mathematical psychology to relate these neural data to behavior. More recently, however, the range of available techniques and paradigms has dramatically broadened, and researchers have begun to harness new approaches to explore how rodents and humans make perceptual decisions. The results have illustrated some striking convergences with findings from the monkey, but also raised new questions and provided new theoretical insights. In this review, we summarize key findings, and highlight open challenges, for understanding perceptual decision making in rodents, monkeys, and humans.

  8. Hantavirus infection in humans and rodents, northwestern Argentina.

    PubMed

    Pini, Noemi; Levis, Silvana; Calderón, Gladys; Ramirez, Josefina; Bravo, Daniel; Lozano, Elena; Ripoll, Carlos; St Jeor, Stephen; Ksiazek, Thomas G; Barquez, Ruben M; Enria, Delia

    2003-09-01

    We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)-endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high prevalence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats.

  9. Multiplex PCR identification of Taenia spp. in rodents and carnivores.

    PubMed

    Al-Sabi, Mohammad N S; Kapel, Christian M O

    2011-11-01

    The genus Taenia includes several species of veterinary and public health importance, but diagnosis of the etiological agent in definitive and intermediate hosts often relies on labor intensive and few specific morphometric criteria, especially in immature worms and underdeveloped metacestodes. In the present study, a multiplex PCR, based on five primers targeting the 18S rDNA and ITS2 sequences, produced a species-specific banding patterns for a range of Taenia spp. Species typing by the multiplex PCR was compared to morphological identification and sequencing of cox1 and/or 12S rDNA genes. As compared to sequencing, the multiplex PCR identified 31 of 32 Taenia metacestodes from rodents, whereas only 14 cysts were specifically identified by morphology. Likewise, the multiplex PCR identified 108 of 130 adult worms, while only 57 were identified to species by morphology. The tested multiplex PCR system may potentially be used for studies of Taenia spp. transmitted between rodents and carnivores.

  10. Hantavirus immunology of rodent reservoirs: current status and future directions.

    PubMed

    Schountz, Tony; Prescott, Joseph

    2014-03-14

    Hantaviruses are hosted by rodents, insectivores and bats. Several rodent-borne hantaviruses cause two diseases that share many features in humans, hemorrhagic fever with renal syndrome in Eurasia or hantavirus cardiopulmonary syndrome in the Americas. It is thought that the immune response plays a significant contributory role in these diseases. However, in reservoir hosts that have been closely examined, little or no pathology occurs and infection is persistent despite evidence of adaptive immune responses. Because most hantavirus reservoirs are not model organisms, it is difficult to conduct meaningful experiments that might shed light on how the viruses evade sterilizing immune responses and why immunopathology does not occur. Despite these limitations, recent advances in instrumentation and bioinformatics will have a dramatic impact on understanding reservoir host responses to hantaviruses by employing a systems biology approach to identify important pathways that mediate virus/reservoir relationships.

  11. Late Pleistocene echimyid rodents (Rodentia, Hystricognathi) from northern Brazil.

    PubMed

    Ferreira, Thais M F; Olivares, Adriana Itati; Kerber, Leonardo; Dutra, Rodrigo P; Avilla, Leonardo S

    2016-06-07

    Echimyidae (spiny rats, tree rats and the coypu) is the most diverse family of extant South American hystricognath rodents (caviomorphs). Today, they live in tropical forests (Amazonian, coastal and Andean forests), occasionally in more open xeric habitats in the Cerrado and Caatinga of northern South America, and open areas across the southern portion of the continent (Myocastor). The Quaternary fossil record of this family remains poorly studied. Here, we describe the fossil echimyids found in karst deposits from southern Tocantins, northern Brazil. The analyzed specimens are assigned to Thrichomys sp., Makalata cf. didelphoides and Proechimys sp. This is the first time that a fossil of Makalata is reported. The Pleistocene record of echimyids from this area is represented by fragmentary remains, which hinders their determination at specific levels. The data reported here contributes to the understanding of the ancient diversity of rodents of this region, evidenced until now in other groups, such as the artiodactyls, cingulates, carnivores, marsupials, and squamate reptiles.

  12. Methods for Dissecting Motivation and Related Psychological Processes in Rodents.

    PubMed

    Ward, Ryan D

    2016-01-01

    Motivational impairments are increasingly recognized as being critical to functional deficits and decreased quality of life in patients diagnosed with psychiatric disease. Accordingly, much preclinical research has focused on identifying psychological and neurobiological processes which underlie motivation . Inferring motivation from changes in overt behavioural responding in animal models, however, is complicated, and care must be taken to ensure that the observed change is accurately characterized as a change in motivation , and not due to some other, task-related process. This chapter discusses current methods for assessing motivation and related psychological processes in rodents. Using an example from work characterizing the motivational impairments in an animal model of the negative symptoms of schizophrenia, we highlight the importance of careful and rigorous experimental dissection of motivation and the related psychological processes when characterizing motivational deficits in rodent models . We suggest that such work is critical to the successful translation of preclinical findings to therapeutic benefits for patients.

  13. Animal models and biomarkers of neuropathy in diabetic rodents

    PubMed Central

    Shaikh, A.S.; Somani, R.S.

    2010-01-01

    Diabetic neuropathy (DN) is a multifactor complication of diabetes. It is a late finding in type 1 diabetes, but can be an early finding in type 2 diabetes. The cause of DN is still unclear and, like other complications of diabetes, it may be the result of various pathological conditions. Animal models and biomarkers of DN have been extensively used in neuropathic research. The most useful model of DN should exhibit the key feature present in human pathology. Diabetic rodents show behavioral, functional, structural and molecular biomarkers and they are widely used as models to investigate the etiology of DN as well as to screen the efficacy of the potential therapeutic interventions. We have reviewed the different animal models and biomarkers of neuropathy in diabetic rodents of either type 1 or type 2 diabetes. PMID:20871761

  14. Hantavirus Infection in Humans and Rodents, Northwestern Argentina

    PubMed Central

    Levis, Silvana; Calderón, Gladys; Ramirez, Josefina; Bravo, Daniel; Lozano, Elena; Ripoll, Carlos; St. Jeor, Stephen; Ksiazek, Thomas G.; Barquez, Ruben M.; Enria, Delia

    2003-01-01

    We initiated a study to elucidate the ecology and epidemiology of hantavirus infections in northern Argentina. The northwestern hantavirus pulmonary syndrome (HPS)–endemic area of Argentina comprises Salta and Jujuy Provinces. Between 1997 and 2000, 30 HPS cases were diagnosed in Jujuy Province (population 512,329). Most patients had a mild clinical course, and the death rate (13.3%) was low. We performed a serologic and epidemiologic survey in residents of the area, in conjunction with a serologic study in rodents. The prevalence of hantavirus antibodies in the general human population was 6.5%, one of the highest reported in the literature. No evidence of interhuman transmission was found, and the high prevalence of hantavirus antibody seemed to be associated with the high infestation of rodents detected in domestic and peridomestic habitats. PMID:14519242

  15. Molecular examinations of Babesia microti in rodents and rodent-attached ticks from urban and sylvatic habitats in Germany.

    PubMed

    Obiegala, Anna; Pfeffer, Martin; Pfister, Kurt; Karnath, Carolin; Silaghi, Cornelia

    2015-06-01

    Small mammals serve as reservoir hosts for tick-borne pathogens, especially for those which are not transmitted transovarially in ticks - such as Babesia microti. Molecular investigations on the prevalence of B. microti in wild small mammals and on attached ticks from differently structured areas may provide information on the circulation of B. microti in different ecological niches. In 2012 and 2013, 622 rodents (396 Myodes glareolus, 178 Apodemus flavicollis, 36 Apodemus sylvaticus, 4 Apodemus agrarius, 7 Microtus arvalis, 1 Microtus agrestis) were captured from three differently structured habitats (urban, sylvatic, recultivated) in Germany. Attached ticks were collected from 449 small mammals (3250 Ixodes ricinus, 7 Ixodes trianguliceps, 133 Dermacentor reticulatus). A representative selection of a maximum of 5 ticks per developmental stage and species per 30 rodents of each species, location and year resulting in 965 ticks was further investigated. DNA was extracted from tick, blood and spleen samples, and tested by PCR for the partial 18S rRNA gene of B. microti with subsequent sequencing. The prevalence was significantly higher in rodents from the sylvatic site (4.6%) than in rodents captured at both other sites (-0.6%) (χ(2)=11.95; p=0.00125). Body and spleen weight of infected M. glareolus from the sylvatic site were significantly higher compared to those from non-infected individuals from that site (p=0.00288 and p=0.00017, respectively). Babesia microti DNA was detected in 3 out of 965 attached ticks (0.3%; 95%CI: 0-1) from all sites, but they derived exclusively from rodents captured at the sylvatic site. At the same site, I. ricinus nymphs (7.7%; 95%CI: 1-25.3) were significantly more often infected than I. ricinus larvae (0%; 95%CI: 0-1.3)(χ(2)=26.72; p<0.0001). The majority of positive rodents was also found at that site. I. trianguliceps occurred exclusively and the majority of M. glareolus at that site. Thus, it may be assumed that the

  16. Nest Predation by Commensal Rodents in Urban Bushland Remnants

    PubMed Central

    2016-01-01

    Exotic predators are a major threat to native wildlife in many parts of the world. Developing and implementing effective strategies to mitigate their effects requires robust quantitative data so that management can be evidence-based, yet in many ecosystems this is missing. Birds in particular have been severely impacted by exotic mammalian predators, and a plethora of studies on islands record predation of bird eggs, fledglings and adults by exotic species such as rodents, stoats and cats. By comparison, few studies have examined nest predation around mainland urban centres which often act as dispersal hubs, especially for commensal species such as rodents. Here, we experimentally examine nest predation rates in habitat patches with varying black rat (Rattus rattus) densities in Sydney, Australia and test whether these exotic rats have the effects expected of exotic predators using effect size benchmarks. In the case where black rats have replaced native Rattus spp., we expected that black rats, being more arboreal than native Rattus spp., would be a significant source of predation on birds because they can readily access the arboreal niche where many birds nest. We tested this idea using above-ground artificial nests to represent those of typical small bird species such as the New Holland honeyeater (Phylidonyris novaehollandiae). We found that fewer eggs were depredated by rodents on sites where we removed black rats compared to unmanipulated sites, and that the effect size calculated from the total number of eggs surviving beyond the typical incubation period was similar to that expected for an exotic predator. Our results suggest that, although Australian birds have co-evolved with native Rattus species, in the case where black rats have replaced native Rattus species, exotic black rats appear to pose an additive source of predation on birds in remnant habitats, most likely due to their ability to climb more efficiently than their native counterparts

  17. Electrophysiological endophenotypes in rodent models of schizophrenia and psychosis

    PubMed Central

    Rosen, Andrew M.; Spellman, Timothy; Gordon, Joshua A.

    2015-01-01

    Schizophrenia is caused by a diverse array of risk factors, and results in a similarly diverse set of symptoms. Electrophysiological endophenotypes lie between risks and symptoms, and have the potential to link the two. Electrophysiological studies in rodent models, described here, demonstrate that widely differing risk factors result in a similar set of core electrophysiological endophenotypes, suggesting the possibility of a shared neurobiological substrate. PMID:25910423

  18. Miniature wireless recording and stimulation system for rodent behavioural testing

    NASA Astrophysics Data System (ADS)

    Pinnell, R. C.; Dempster, J.; Pratt, J.

    2015-12-01

    Objective. Elucidation of neural activity underpinning rodent behaviour has traditionally been hampered by the use of tethered systems and human involvement. Furthermore the combination of deep-brain stimulation (DBS) and various neural recording modalities can lead to complex and time-consuming laboratory setups. For studies of this type, novel tools are required to drive forward this research. Approach. A miniature wireless system weighing 8.5 g (including battery) was developed for rodent use that combined multichannel DBS and local-field potential (LFP) recordings. Its performance was verified in a working memory task that involved 4-channel fronto-hippocampal LFP recording and bilateral constant-current fimbria-fornix DBS. The system was synchronised with video-tracking for extraction of LFP at discrete task phases, and DBS was activated intermittently at discrete phases of the task. Main results. In addition to having a fast set-up time, the system could reliably transmit continuous LFP at over 8 hours across 3-5 m distances. During the working memory task, LFP pertaining to discrete task phases was extracted and compared with well-known neural correlates of active exploratory behaviour in rodents. DBS could be wirelessly activated/deactivated at any part of the experiment during EEG recording and transmission, allowing for a seamless integration of this modality. Significance. The wireless system combines a small size with a level of robustness and versatility that can greatly simplify rodent behavioural experiments involving EEG recording and DBS. Designed for versatility and simplicity, the small size and low-cost of the system and its receiver allow for enhanced portability, fast experimental setup times, and pave the way for integration with more complex behaviour.

  19. Evolving Communicative Complexity: Insight from Rodents and Beyond

    DTIC Science & Technology

    2012-01-01

    evolve is an active question in behavioural ecology. Sciurid rodents (ground squirrels, prairie dogs and marmots ) provide an excellent model system for...the situation [46–48]. For example, many species of marmots alter the rate of their alarm calls with the urgency of the situation or the degree of risk...re- lated genera, prairie dogs Cynomys spp., and marmots Marmota spp.), present an excellent model comparative system for studying the relationship

  20. Telomerase protects adult rodent olfactory ensheathing glia from early senescence.

    PubMed

    Llamusí, María-Beatriz; Rubio, Mari-Paz; Ramón-Cueto, Almudena

    2011-05-01

    Adult olfactory bulb ensheathing glia (OB-OEG) promote the repair of acute, subacute, and chronic spinal cord injuries and autologous transplantation is a feasible approach. There are interspecies differences between adult rodent and primate OB-OEG related to their longevity in culture. Whereas primate OB-OEG exhibit a relatively long life span, under the same culture conditions rodent OB-OEG divide just three to four times, are sensitive to oxidative stress and become senescent after the third week in vitro. Telomerase is a "physiological key regulator" of the life span of normal somatic cells and also has extratelomeric functions such as increased resistance to oxidative stress. To elucidate whether telomerase has a role in the senescence of rodent OB-OEG, we have introduced the catalytic subunit of telomerase mTERT into cultures of these cells by retroviral infection. Native and modified adult rat OB-OEG behaved as telomerase-competent cells as they divided while expressing mTERT but entered senescence once the gene switched off. After ectopic expression of mTERT, OB-OEG resumed division at a nonsenescent rate, expressed p75 and other OEG markers, and exhibited the morphology of nonsenescent OB-OEG. The nonsenescent period of mTERT-OEG lasted 9weeks and then ectopic mTERT switched off and cells entered senescence again. Our results suggest a role of telomerase in early senescence of adult rodent OB-OEG cultures and a protection from oxidative damage. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair.

  1. Nest Predation by Commensal Rodents in Urban Bushland Remnants.

    PubMed

    Smith, Helen M; Dickman, Chris R; Banks, Peter B

    2016-01-01

    Exotic predators are a major threat to native wildlife in many parts of the world. Developing and implementing effective strategies to mitigate their effects requires robust quantitative data so that management can be evidence-based, yet in many ecosystems this is missing. Birds in particular have been severely impacted by exotic mammalian predators, and a plethora of studies on islands record predation of bird eggs, fledglings and adults by exotic species such as rodents, stoats and cats. By comparison, few studies have examined nest predation around mainland urban centres which often act as dispersal hubs, especially for commensal species such as rodents. Here, we experimentally examine nest predation rates in habitat patches with varying black rat (Rattus rattus) densities in Sydney, Australia and test whether these exotic rats have the effects expected of exotic predators using effect size benchmarks. In the case where black rats have replaced native Rattus spp., we expected that black rats, being more arboreal than native Rattus spp., would be a significant source of predation on birds because they can readily access the arboreal niche where many birds nest. We tested this idea using above-ground artificial nests to represent those of typical small bird species such as the New Holland honeyeater (Phylidonyris novaehollandiae). We found that fewer eggs were depredated by rodents on sites where we removed black rats compared to unmanipulated sites, and that the effect size calculated from the total number of eggs surviving beyond the typical incubation period was similar to that expected for an exotic predator. Our results suggest that, although Australian birds have co-evolved with native Rattus species, in the case where black rats have replaced native Rattus species, exotic black rats appear to pose an additive source of predation on birds in remnant habitats, most likely due to their ability to climb more efficiently than their native counterparts

  2. Performance analysis of exam gloves used for aseptic rodent surgery.

    PubMed

    LeMoine, Dana M; Bergdall, Valerie K; Freed, Carrie

    2015-05-01

    Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP-PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham 'exertion' activity. According to these criteria, 94% of HP-PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP-PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries.

  3. Genotypes of pathogenic Leptospira spp isolated from rodents in Argentina

    PubMed Central

    Loffler, Sylvia Grune; Pavan, Maria Elisa; Vanasco, Bibiana; Samartino, Luis; Suarez, Olga; Auteri, Carmelo; Romero, Graciela; Brihuega, Bibiana

    2014-01-01

    Leptospirosis is the most widespread zoonosis in the world and significant efforts have been made to determine and classify pathogenic Leptospira strains. This zoonosis is maintained in nature through chronic renal infections of carrier animals, with rodents and other small mammals serving as the most important reservoirs. Additionally, domestic animals, such as livestock and dogs, are significant sources of human infection. In this study, a multiple-locus variable-number tandem repeat analysis (MLVA) was applied to genotype 22 pathogenic Leptospira strains isolated from urban and periurban rodent populations from different regions of Argentina. Three MLVA profiles were identified in strains belonging to the species Leptospira interrogans (serovars Icterohaemorrhagiae and Canicola); one profile was observed in serovar Icterohaemorrhagiae and two MLVA profiles were observed in isolates of serovars Canicola and Portlandvere. All strains belonging to Leptospira borgpetersenii serovar Castellonis exhibited the same MLVA profile. Four different genotypes were isolated from urban populations of rodents, including both mice and rats and two different genotypes were isolated from periurban populations. PMID:24676656

  4. Genotypes of pathogenic Leptospira spp isolated from rodents in Argentina.

    PubMed

    Loffler, Sylvia Grune; Pavan, Maria Elisa; Vanasco, Bibiana; Samartino, Luis; Suarez, Olga; Auteri, Carmelo; Romero, Graciela; Brihuega, Bibiana

    2014-04-01

    Leptospirosis is the most widespread zoonosis in the world and significant efforts have been made to determine and classify pathogenic Leptospira strains. This zoonosis is maintained in nature through chronic renal infections of carrier animals, with rodents and other small mammals serving as the most important reservoirs. Additionally, domestic animals, such as livestock and dogs, are significant sources of human infection. In this study, a multiple-locus variable-number tandem repeat analysis (MLVA) was applied to genotype 22 pathogenic Leptospira strains isolated from urban and periurban rodent populations from different regions of Argentina. Three MLVA profiles were identified in strains belonging to the species Leptospira interrogans (serovars Icterohaemorrhagiae and Canicola); one profile was observed in serovar Icterohaemorrhagiae and two MLVA profiles were observed in isolates of serovars Canicola and Portlandvere. All strains belonging to Leptospira borgpetersenii serovar Castellonis exhibited the same MLVA profile. Four different genotypes were isolated from urban populations of rodents, including both mice and rats and two different genotypes were isolated from periurban populations.

  5. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior

    PubMed Central

    Poland, Ryan S.; Bull, Cecilia; Syed, Wahab A.; Bowers, M. Scott

    2015-01-01

    Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as appropriate models, partly because the response to behaviorally relevant stimuli and the circuitry parsing stimulus-action outcomes is astonishingly similar between humans and rodents. In studying molecular substrates of complex behaviors, the microinjection of reagents that modify, augment, or silence specific systems is an invaluable technique. However, it is crucial that the microinjection site is precisely targeted in order to aid interpretation of the results. We present a method for the manufacture of surgical implements and microinjection needles that enables accurate microinjection and unlimited customizability with minimal cost. Importantly, this technique can be successfully completed in awake rodents if conducted in conjunction with other JoVE articles that covered requisite surgical procedures. Additionally, there are many behavioral paradigms that are well suited for measuring motivation. The progressive ratio is a commonly used method that quantifies the efficacy of a reinforcer to maintain responding despite an (often exponentially) increasing work requirement. This assay is sensitive to reinforcer magnitude and pharmacological manipulations, which allows reinforcing efficacy and/ or motivation to be determined. We also present a straightforward approach to program operant software to accommodate a progressive ratio reinforcement schedule. PMID:26437131

  6. Two New Mylagaulid Rodents from the Early Miocene of China

    PubMed Central

    Lu, Xiaoyu; Ni, Xijun; Li, Lüzhou; Li, Qiang

    2016-01-01

    Mylagaulid fossorial rodents are a common component of North American Miocene fossil faunas. However outside of North America, only three species are known from Asia. Here we report two new mylagaulids, Irtyshogaulus minor gen. et sp. nov. and Irtyshogaulus major gen. et sp. nov., recovered from early Miocene sediments in the Junggar Basin in northwestern China. The two new taxa are small-sized, high-crowned promylagauline rodents. Their lower molars possess high metastylid crests, small mesostylids, broad and posterolingually expanded labial inflections, and transversely extending metalophid IIs. The mesoconid is absent in both species. The anterior and posterior fossettids are large and equally developed. Their upper M1-2s possess a square occlusal surface with five deep fossettes. The two new taxa are distinguished from each other mainly by their size, the morphology of fossettes and fossettids, development of mesial and distal lophs, posterior reduction of M3, and the orientation of m2 hypolophid. Our phylogenetic analysis indicates that Irtyshogaulus and Lamugaulus (another early Miocene Asian mylagaulid) are sister taxa. The two genera are nested among the North American promylagaulines, and share a common ancestor from North America, indicating early Miocene intercontinental dispersal within this clade of rodents. PMID:27486803

  7. Experimental models of renal calcium stones in rodents

    PubMed Central

    Bilbault, Héloïse; Haymann, Jean-Philippe

    2016-01-01

    In human nephrolithiasis, most stones are containing calcium and are located within urinary cavities; they may contain monohydrate calcium oxalate, dihydrate calcium oxalate and/or calcium phosphates in various proportion. Nephrolithiasis may also be associated with nephrocalcinosis, i.e., crystal depositions in tubular lumen and/or interstitium, an entity which suggests specific pathological processes. Several rodents models have been developed in order to study the pathophysiology of intrarenal crystal formation. We review here calcium rodent models classified upon the presence of nephrolithiasis and/or nephrocalcinosis. As rodents are not prone to nephrolithiasis, models require the induction of a long standing hypercalciuria or hyperoxaluria (thus explaining the very few studies reported), conversely to nephrocalcinosis which may occur within hours or days. Whereas a nephrotoxicity leading to tubular injury and regeneration appears as a critical event for crystal retention in nephrocalcinosis models, surprisingly very little is known about the physiopathology of crystal attachment to urothelium in nephrolithiasis. Creating new models of nephrolithiasis especially in different genetic mice strains appears an important challenge in order to unravel the early mechanisms of urinary stone formation in papilla and fornices. PMID:26981444

  8. Towards an integrative model of sociality in caviomorph rodents

    PubMed Central

    Hayes, Loren D.; Burger, Joseph Robert; Soto-Gamboa, Mauricio; Sobrero, Raúl; Ebensperger, Luis A

    2012-01-01

    In the late 1990s and early 2000s it was recognized that behavioral ecologists needed to study the sociality of caviomorph rodents (New World hystricognaths) before generalizations about rodent sociality could be made. Researchers identified specific problems facing individuals interested in caviomorph sociality, including a lack of information on the proximate mechanisms of sociality, role of social environment in development, and geographical or intraspecific variation in social systems. Since then researchers have described the social systems of many previously understudied species, including some with broad geographical ranges. Researchers have done a good job of determining the role of social environments in development and identifying the costs and benefits of social living. However, relatively little is known about the proximate mechanisms of social behavior and fitness consequences, limiting progress toward the development of integrative (evolutionary-mechanistic) models for sociality. To develop integrative models behavioral ecologists studying caviomorph rodents must generate information on the fitness consequences of different types of social organization, brain mechanisms, and endocrine substrates of sociality. We review our current understanding and future directions for research in these conceptual areas. A greater understanding of disease ecology, particularly in species carrying Old World parasites, is needed before we can identify potential links between social phenotypes, mechanism, and fitness. PMID:22328791

  9. Unexpected primitive rodents in the Quaternary of Argentina

    NASA Astrophysics Data System (ADS)

    Vucetich, María G.; Vieytes, Emma C.; Verzi, Diego H.; Noriega, Jorge I.; Tonni, Eduardo P.

    2005-10-01

    This article describes the first fossils recorded in the Hernandarias Formation (Pleistocene) in Entre Ríos province (eastern Argentina). They are represented by three teeth assigned to the caviomorph rodents (Rodentia, Mammalia) Aenigmys diamantensis gen. et sp. nov. and Eumysops. To establish the phylogenetic affinities of the two most enigmatic teeth, their enamel microstructure was studied. Aenigmys diamantensis is considered the most primitive taxon of a clade formed by Dinomyidae-Neoepiblemidae-Heptaxodontidae. Evidence of the close relationships among these families also is presented herein. The new fossils reinforce previous hypotheses about the survival of primitive Brazilian taxa after their extinction in the Pampas and Patagonia of southern South America. They also show that the diversity of caviomorph rodents during the Quaternary was greater than supposed and that an important Quaternary extinction, not previously detected, affected several lineages. With the available evidence, it is not possible to determine if these rodents indicate a warm pulse or a particular biogeographic situation in Entre Ríos.

  10. Isolating human DNA repair genes using rodent-cell mutants

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-03-23

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

  11. Rodent models for resolving extremes of exercise and health

    PubMed Central

    North, Kathryn N.; Koch, Lauren G.; Britton, Steven L.; Nogales-Gadea, Gisela; Lucia, Alejandro

    2015-01-01

    The extremes of exercise capacity and health are considered a complex interplay between genes and the environment. In general, the study of animal models has proven critical for deep mechanistic exploration that provides guidance for focused and hypothesis-driven discovery in humans. Hypotheses underlying molecular mechanisms of disease and gene/tissue function can be tested in rodents to generate sufficient evidence to resolve and progress our understanding of human biology. Here we provide examples of three alternative uses of rodent models that have been applied successfully to advance knowledge that bridges our understanding of the connection between exercise capacity and health status. First we review the strong association between exercise capacity and all-cause morbidity and mortality in humans through artificial selection on low and high exercise performance in the rat and the consequent generation of the “energy transfer hypothesis.” Second we review specific transgenic and knockout mouse models that replicate the human disease condition and performance. This includes human glycogen storage diseases (McArdle and Pompe) and α-actinin-3 deficiency. Together these rodent models provide an overview of the advancements of molecular knowledge required for clinical translation. Continued study of these models in conjunction with human association studies will be critical to resolving the complex gene-environment interplay linking exercise capacity, health, and disease. PMID:26395598

  12. Mycobacterium microti Infection (Vole Tuberculosis) in Wild Rodent Populations

    PubMed Central

    Cavanagh, Rachel; Begon, Michael; Bennett, Malcolm; Ergon, Torbjørn; Graham, Isla M.; de Haas, Petra E. W.; Hart, C. A.; Koedam, Marianne; Kremer, Kristin; Lambin, Xavier; Roholl, Paul; Soolingen, Dick van

    2002-01-01

    Mycobacterium microti (vole tuberculosis) infections in small wild mammals were first described more than 60 years ago in several populations in Great Britain. Few studies of vole tuberculosis have been undertaken since then, and little is known about the relationship between M. microti isolates originating from different populations or at different times or of the prevalence of this infection in wild rodent populations, despite human cases of M. microti infections being increasingly reported. In this study, field voles (Microtus agrestis), bank voles (Clethrionomys glareolus), and wood mice (Apodemus sylvaticus) were found to be infected, with up to 8% having external tuberculous signs, in wild populations in Northumberland and Cheshire, England. Spoligotyping applied directly to the clinical material simultaneously detected and typed M. microti bacteria in skin lesions, lymph glands, and internal abcesses. IS6110 restriction fragment length polymorphism typing of cultured bacteria was used to compare these isolates with previously isolated strains from both animals and humans. This demonstrated that although the current rodent isolates were distinct from those isolated from voles in the 1930s in Great Britain, they had a high degree of similarity to these strains and were distinct from the M. microti isolates from humans, a pig, and a ferret from The Netherlands. Thus, M. microti infection seems to be widespread in wild rodent populations, but more studies are needed to understand how M. microti might be transmitted from animals to humans and to determine better the zoonotic risk posed. PMID:12202566

  13. Rodent Models of Depression: Neurotrophic and Neuroinflammatory Biomarkers

    PubMed Central

    Stepanichev, Mikhail; Dygalo, Nikolay N.; Grigoryan, Grigory; Shishkina, Galina T.; Gulyaeva, Natalia

    2014-01-01

    Rodent models are an indispensable tool for studying etiology and progress of depression. Since interrelated systems of neurotrophic factors and cytokines comprise major regulatory mechanisms controlling normal brain plasticity, impairments of these systems form the basis for development of cerebral pathologies, including mental diseases. The present review focuses on the numerous experimental rodent models of depression induced by different stress factors (exteroceptive and interoceptive) during early life (including prenatal period) or adulthood, giving emphasis to the data on the changes of neurotrophic factors and neuroinflammatory indices in the brain. These parameters are closely related to behavioral depression-like symptoms and impairments of neuronal plasticity and are both gender- and genotype-dependent. Stress-related changes in expression of neurotrophins and cytokines in rodent brain are region-specific. Some contradictory data reported by different groups may be a consequence of differences of stress paradigms or their realization in different laboratories. Like all experimental models, stress-induced depression-like conditions are experimental simplification of clinical depression states; however, they are suitable for understanding the involvement of neurotrophic factors and cytokines in the pathogenesis of the disease—a goal unachievable in the clinical reality. These major regulatory systems may be important targets for therapeutic measures as well as for development of drugs for treatment of depression states. PMID:24999483

  14. A Fully Automated High-Throughput Training System for Rodents

    PubMed Central

    Poddar, Rajesh; Kawai, Risa; Ölveczky, Bence P.

    2013-01-01

    Addressing the neural mechanisms underlying complex learned behaviors requires training animals in well-controlled tasks, an often time-consuming and labor-intensive process that can severely limit the feasibility of such studies. To overcome this constraint, we developed a fully computer-controlled general purpose system for high-throughput training of rodents. By standardizing and automating the implementation of predefined training protocols within the animal’s home-cage our system dramatically reduces the efforts involved in animal training while also removing human errors and biases from the process. We deployed this system to train rats in a variety of sensorimotor tasks, achieving learning rates comparable to existing, but more laborious, methods. By incrementally and systematically increasing the difficulty of the task over weeks of training, rats were able to master motor tasks that, in complexity and structure, resemble ones used in primate studies of motor sequence learning. By enabling fully automated training of rodents in a home-cage setting this low-cost and modular system increases the utility of rodents for studying the neural underpinnings of a variety of complex behaviors. PMID:24349451

  15. Performance Analysis of Exam Gloves Used for Aseptic Rodent Surgery

    PubMed Central

    LeMoine, Dana M; Bergdall, Valerie K; Freed, Carrie

    2015-01-01

    Aseptic technique includes the use of sterile surgical gloves for survival surgeries in rodents to minimize the incidence of infections. Exam gloves are much less expensive than are surgical gloves and may represent a cost-effective, readily available option for use in rodent surgery. This study examined the effectiveness of surface disinfection of exam gloves with 70% isopropyl alcohol or a solution of hydrogen peroxide and peracetic acid (HP–PA) in reducing bacterial contamination. Performance levels for asepsis were met when gloves were negative for bacterial contamination after surface disinfection and sham ‘exertion’ activity. According to these criteria, 94% of HP–PA-disinfected gloves passed, compared with 47% of alcohol-disinfected gloves. In addition, the effect of autoclaving on the integrity of exam gloves was examined, given that autoclaving is another readily available option for aseptic preparation. Performance criteria for glove integrity after autoclaving consisted of: the ability to don the gloves followed by successful simulation of wound closure and completion of stretch tests without tearing or observable defects. Using this criteria, 98% of autoclaved nitrile exam gloves and 76% of autoclaved latex exam gloves met performance expectations compared with the performance of standard surgical gloves (88% nitrile, 100% latex). The results of this study support the use of HP–PA-disinfected latex and nitrile exam gloves or autoclaved nitrile exam gloves as viable cost-effective alternatives to sterile surgical gloves for rodent surgeries. PMID:26045458

  16. Rodent models for resolving extremes of exercise and health.

    PubMed

    Garton, Fleur C; North, Kathryn N; Koch, Lauren G; Britton, Steven L; Nogales-Gadea, Gisela; Lucia, Alejandro

    2016-02-01

    The extremes of exercise capacity and health are considered a complex interplay between genes and the environment. In general, the study of animal models has proven critical for deep mechanistic exploration that provides guidance for focused and hypothesis-driven discovery in humans. Hypotheses underlying molecular mechanisms of disease and gene/tissue function can be tested in rodents to generate sufficient evidence to resolve and progress our understanding of human biology. Here we provide examples of three alternative uses of rodent models that have been applied successfully to advance knowledge that bridges our understanding of the connection between exercise capacity and health status. First we review the strong association between exercise capacity and all-cause morbidity and mortality in humans through artificial selection on low and high exercise performance in the rat and the consequent generation of the "energy transfer hypothesis." Second we review specific transgenic and knockout mouse models that replicate the human disease condition and performance. This includes human glycogen storage diseases (McArdle and Pompe) and α-actinin-3 deficiency. Together these rodent models provide an overview of the advancements of molecular knowledge required for clinical translation. Continued study of these models in conjunction with human association studies will be critical to resolving the complex gene-environment interplay linking exercise capacity, health, and disease.

  17. Fire ignition during laser surgery in pet rodents

    PubMed Central

    2012-01-01

    Background Laser surgery is an attractive alternative to other means of section device in terms of tissue inflammation and interaction, which has been extensively used in human and veterinary medicine. Although accidental ignition during laser surgeries is sporadically reported in human medical literature, to the authors’ knowledge this is the first report regarding laser-dependent fire ignition during surgery in veterinary medicine. Case presentation Two rodents, a 13-month old, 27-gram, male pet mouse (Mus musculus) and a 1-year old, female Russian hamster (Phodopus sungorus), underwent surgical removal of masses with diode laser. During the surgical procedures fires ignited from the face masks. The mouse presented severe burns on the head and both forelimbs, it was hospitalized and approximately 2 months after surgery burns were resolved. The hamster presented severe burns on the face and the proximal regions of the body. At 72 hours from the accident the hamster was euthanized. Conclusion The present report suggests that fire ignition is a potential life-threatening complication of laser surgery in non-intubated rodents maintained under volatile anesthesia. High oxygen concentrations, the presence of combustible, and the narrowness of the surgical field with the face mask during laser surgery on rodents are risk factors for fire ignition. PMID:23009047

  18. Results from a Survey of Current Practices for Sampling of Nervous System in Rodents and Non-rodents in General Toxicity Studies

    EPA Science Inventory

    A survey of current practices for sampling and examination of the nervous system in rodents and non-rodents for general and neurotoxicity (NT) studies was conducted by the Nervous System Sampling Subcommittee of the STP. For general toxicity studies most of those surveyed (>63%) ...

  19. Forest rodents provide directed dispersal of Jeffrey pine seeds

    USGS Publications Warehouse

    Briggs, J.S.; Wall, S.B.V.; Jenkins, S.H.

    2009-01-01

    Some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. We investigated whether this mutualistic interaction occurs between granivorous rodents and Jeffrey pine (Pinus jeffreyi) in the eastern Sierra Nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (Peromyscus maniculatus), yellow-pine and long-eared chipmunks (Tamias amoenus and T. quadrimaculatus), and golden-mantled ground squirrels (Spermophilus lateralis). We conducted two caching studies using radio-labeled seeds, the first with individual animals in field enclosures and the second with a community of rodents in open forest. We used artificial caches to compare the fates of seeds placed at the range of microsites and depths used by animals with the fates of seeds dispersed abiotically. Finally, we examined the distribution and survival of naturally establishing seedlings over an eight-year period.Several lines of evidence suggested that this community of rodents provided directed dispersal. Animals preferred to cache seeds in microsites that were favorable for emergence or survival of seedlings and avoided caching in microsites in which seedlings fared worst. Seeds buried at depths typical of animal caches (5–25 mm) produced at least five times more seedlings than did seeds on the forest floor. The four species of rodents differed in the quality of dispersal they provided. Small, shallow caches made by deer mice most resembled seeds dispersed by abiotic processes, whereas many of the large caches made by ground squirrels were buried too deeply for successful emergence of seedlings. Chipmunks made the greatest number of caches within the range of depths and microsites favorable for establishment of pine seedlings. Directed dispersal is an important element of the population dynamics of Jeffrey pine, a

  20. Forest rodents provide directed dispersal of Jeffrey pine seeds.

    PubMed

    Briggs, Jennifer S; Vander Wall, Stephen B; Jenkins, Stephen H

    2009-03-01

    Some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. We investigated whether this mutualistic interaction occurs between granivorous rodents and Jeffrey pine (Pinus jeffreyi) in the eastern Sierra Nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (Peromyscus maniculatus), yellow-pine and long-eared chipmunks (Tamias amoenus and T. quadrimaculatus), and golden-mantled ground squirrels (Spermophilus lateralis). We conducted two caching studies using radio-labeled seeds, the first with individual animals in field enclosures and the second with a community of rodents in open forest. We used artificial caches to compare the fates of seeds placed at the range of microsites and depths used by animals with the fates of seeds dispersed abiotically. Finally, we examined the distribution and survival of naturally establishing seedlings over an eight-year period. Several lines of evidence suggested that this community of rodents provided directed dispersal. Animals preferred to cache seeds in microsites that were favorable for emergence or survival of seedlings and avoided caching in microsites in which seedlings fared worst. Seeds buried at depths typical of animal caches (5-25 mm) produced at least five times more seedlings than did seeds on the forest floor. The four species of rodents differed in the quality of dispersal they provided. Small, shallow caches made by deer mice most resembled seeds dispersed by abiotic processes, whereas many of the large caches made by ground squirrels were buried too deeply for successful emergence of seedlings. Chipmunks made the greatest number of caches within the range of depths and microsites favorable for establishment of pine seedlings. Directed dispersal is an important element of the population dynamics of Jeffrey pine, a

  1. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species

    PubMed Central

    Hautier, Lionel; Marivaux, Laurent; Vianey-Liaud, Monique

    2016-01-01

    Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest. Osteological characters were described, compared, mechanically interpreted, and correlated with a “functional sequence” comprising six categories linked to the lifestyle and locomotion (jumping, cursorial, generalist, fossorial, climber and semi-aquatic). Some character states are typical of some of these categories, especially arboreal climbers, fossorial and “cursorial-jumping” taxa. Such reliable characters might be used to infer locomotor behaviours in extinct species. Linear discriminant analyses (LDAs) were used on a wider sample of species and show that astragalar and calcaneal characters can be used to discriminate the categories among extant species whereas a posteriori inferences on extinct species should be examined with caution. PMID:27761303

  2. Ecomorphological analysis of the astragalo-calcaneal complex in rodents and inferences of locomotor behaviours in extinct rodent species.

    PubMed

    Ginot, Samuel; Hautier, Lionel; Marivaux, Laurent; Vianey-Liaud, Monique

    2016-01-01

    Studies linking postcranial morphology with locomotion in mammals are common. However, such studies are mostly restricted to caviomorphs in rodents. We present here data from various families, belonging to the three main groups of rodents (Sciuroidea, Myodonta, and Ctenohystrica). The aim of this study is to define morphological indicators for the astragalus and calcaneus, which allow for inferences to be made about the locomotor behaviours in rodents. Several specimens were dissected and described to bridge the myology of the leg with the morphology of the bones of interest. Osteological characters were described, compared, mechanically interpreted, and correlated with a "functional sequence" comprising six categories linked to the lifestyle and locomotion (jumping, cursorial, generalist, fossorial, climber and semi-aquatic). Some character states are typical of some of these categories, especially arboreal climbers, fossorial and "cursorial-jumping" taxa. Such reliable characters might be used to infer locomotor behaviours in extinct species. Linear discriminant analyses (LDAs) were used on a wider sample of species and show that astragalar and calcaneal characters can be used to discriminate the categories among extant species whereas a posteriori inferences on extinct species should be examined with caution.

  3. Cross-reactivity of secondary antibodies against African rodents and application for sero-surveillance.

    PubMed

    Nakamura, Ichiro; Hang'ombe, Bernard Mudenda; Sawa, Hirofumi; Kobayashi, Shintaro; Orba, Yasuko; Ishii, Akihiro; Thomas, Yuka; Isozumi, Rie; Yoshimatsu, Kumiko; Mweene, Aaron S; Takada, Ayato; Sugimoto, Chihiro; Arikawa, Jiro

    2013-01-01

    A total of 466 rodents were captured in the Republic of Zambia from 2006 to 2010. Based on morphological observations and phylogenetic analyses of mitochondrial gene sequences, rodents were divided into 10 groups consisting of 39 Rattus rodents, 263 multimammate rats, 18 other Murinae rodents, 95 gerbils, 11 pouched mice, 1 giant-pouched rat, 38 fat mice and 1 dormouse. Rodent antibodies except that from Rattus were examined for their cross-reactivity to commercially available antibody detection reagents. Anti-mouse immunoglobulin G (IgG) was most cross-reactive to heterologous antibodies including multimammate rat, gerbil, pouched mouse and fat mouse. Thus, anti-mouse IgG would be a useful detection tool in serological examination of the Zambian rodent population. Preliminary sero-surveillance for plague, leptospirosis and hantavirus infection was performed by ELISA.

  4. Seasonal Dynamics of Anaplasma phagocytophila in a Rodent-Tick (Ixodes trianguliceps) System, United Kingdom

    PubMed Central

    Begon, Michael; Bennett, Malcolm; Woldehiwet, Zerai; Ogden, Nicholas H.

    2003-01-01

    We investigated the reservoir role of European wild rodents for Anaplasma phagocytophila using polymerase chain reaction (PCR) analysis of blood collected from individually tagged rodents captured monthly over 2 years. The only tick species observed in the woodland study site was Ixodes trianguliceps, and ruminant reservoir hosts were not known to occur. A. phagocytophila infections were detected in both bank voles and wood mice but were restricted to periods of peak nymphal and adult tick activity. Most PCR-positive rodents were positive only once, suggesting that rodent infections are generally short-lived and that ticks rather than rodents may maintain the infection over winter. Bank voles were more likely to be PCR positive than wood mice, possibly because detectable infections are longer lived in bank voles. This study confirms that woodland rodents can maintain A. phagocytophila in Great Britain in the absence of other reservoir hosts and suggests that I. trianguliceps is a competent vector. PMID:12533283

  5. Mammary gland neoplasia in long-term rodent studies.

    PubMed Central

    Russo, I H; Russo, J

    1996-01-01

    Breast cancer, the most frequent spontaneous malignancy diagnosed in women in the western world, is continuously increasing in incidence in industrialized nations. Although breast cancer develops in women as the result of a combination of external and endogenous factors such as exposure to ionizing radiation, diet, socioeconomic status, and endocrinologic, familial, or genetic factors, no specific etiologic agent(s) or the mechanisms responsible of the disease has been identified as yet. Thus, experimental models that exhibit the same complex interactions are needed for testing various mechanisms and for assessing the carcinogenic potential of given chemicals. Rodent mammary carcinomas represent such a model to a great extent because, in these species, mammary cancer is a multistep complex process that can be induced by either chemicals, radiation, viruses, or genetic factors. Long-term studies in rodent models have been particularly useful for dissecting the initiation, promotion, and progression steps of carcinogenesis. The susceptibility of the rodent mammary gland to develop neoplasms has made this organ a unique target for testing the carcinogenic potential of specific genotoxic chemicals and environmental agents. Mammary tumors induced by indirect- or direct-acting carcinogens such as 7, 12-dimethlbenz(a)anthracene or N-methyl-N-nitrosourea are, in general, hormone dependent adenocarcinomas whose incidence, number of tumors per animal, tumor latency, and tumor type are influenced by the age, reproductive history, and endocarinologic milieu of the host at the time of carcinogen exposure. Rodent models are informative in the absence of human data. They have provided valuable information on the dose and route of administration to be used and optimal host conditions for eliciting maximal tumorigenic response. Studies of the influence of normal gland development on the pathogenesis of chemically induced mammary carcinomas have clarified the role of differentiation

  6. Tularemia and plague survey in rodents in an earthquake zone in southeastern Iran

    PubMed Central

    Gyuranecz, Miklós

    2015-01-01

    OBJECTIVES: Earthquakes are one the most common natural disasters that lead to increased mortality and morbidity from transmissible diseases, partially because the rodents displaced by an earthquake can lead to an increased rate of disease transmission. The aim of this study was to evaluate the prevalence of plague and tularemia in rodents in the earthquake zones in southeastern Iran. METHODS: In April 2013, a research team was dispatched to explore the possible presence of diseases in rodents displaced by a recent earthquake magnitude 7.7 around the cities of Khash and Saravan in Sistan and Baluchestan Province. Rodents were trapped near and in the earthquake zone, in a location where an outbreak of tularemia was reported in 2007. Rodent serums were tested for a serological survey using an enzyme-linked immunosorbent assay. RESULTS: In the 13 areas that were studied, nine rodents were caught over a total of 200 trap-days. Forty-eight fleas and 10 ticks were obtained from the rodents. The ticks were from the Hyalomma genus and the fleas were from the Xenopsylla genus. All the trapped rodents were Tatera indica. Serological results were negative for plague, but the serum agglutination test was positive for tularemia in one of the rodents. Tatera indica has never been previously documented to be involved in the transmission of tularemia. CONCLUSIONS: No evidence of the plague cycle was found in the rodents of the area, but evidence was found of tularemia infection in rodents, as demonstrated by a positive serological test for tularemia in one rodent. PMID:26602769

  7. [Functional motor asymmetry in three species of mouse rodents from natural populations].

    PubMed

    Agulova, L P; Bol'shakova, N P; Andreevskikh, A V; Suchkova, N G; Kravchenko, L B; Moskvitina, N S

    2011-01-01

    Motor asymmetry of paws was studied in three species of mouse rodents (Apodemus agrarius, Clethrionomys glareolus, Clethrionomys rutilus) from natural populations. The prevalence of right-hand asymmetry was revealed in both males and females of all studied species. The spatial and temporal variability of asymmetry structures was shown. The increased number of left-handed rodents was observed in unfavorable habitats. A possible adaptive role of the functional motor asymmetry exemplified by small rodents is discussed.

  8. Sex differences in chronic stress effects on cognition in rodents.

    PubMed

    Luine, Victoria; Gomez, Juan; Beck, Kevin; Bowman, Rachel

    2017-01-01

    Chronic stress causes deleterious changes in physiological function in systems ranging from neural cells in culture to laboratory rodents, sub-human primates and humans. It is notable, however, that the vast majority of research in this area has been conducted in males. In this review, we provide information about chronic stress effects on cognition in female rodents and contrast it with responses in male rodents. In general, females show cognitive resilience to chronic stressors which impair male cognitive function using spatial tasks including the radial arm maze, radial arm water maze, Morris water maze, Y-maze and object placement. Moreover, stress often enhances female performance in some of these cognitive tasks. Memory in females is not affected by stress in non-spatial memory tasks like recognition memory and temporal order recognition memory while males show impaired memory following stress. We discuss possible bases for these sex-dependent differences including the use of different strategies by the sexes to solve cognitive tasks. Whether the sex differences result from changes in non-mnemonic factors is also considered. Sex-dependent differences in alcohol and drug influences on stress responses are also described. Finally, the role of neurally derived estradiol in driving sex differences and providing resilience to stress in females is shown. The importance of determining the nature and extent of sex differences in stress responses is that such differences may provide vital information for understanding why some stress related diseases have different incidence rates between the sexes and for developing novel therapeutic treatments.

  9. Findings of mycobacteria in insectivores and small rodents.

    PubMed

    Fischer, O; Mátlová, L; Bartl, J; Dvorská, L; Melichárek, I; Pavlík, I

    2000-01-01

    The organs of 30 insectivorous mammals and 62 rodents from areas inhabited by people or livestock where cattle paratuberculosis or mycobacterial infections of swine had been found to occur were examined by cultivation during the monitoring of occurrence and spread of mycobacterioses in cattle and swine. Mycobacteria were found in the organs of 3 insectivores (10%) and 6 rodents (9.7%). Mycobacterium chelonae was isolated from the organs of the lesser white-toothed shrew (Crocidura suaveolens) and the common vole (Microtus arvalis), and M. vaccae and M. avium subsp. avium (IS901+, serotype 1) from the organs of the common shrew (Sorex araneus). M. avium subsp. avium (IS901+, serotype 1) was also isolated from the organs of the yellow-necked mouse (Apodemus flavicollis). Slow-growing mycobacteria of group III (according to Runyon) were isolated from the organs of the mouse (Mus musculus sensu lato) and the yellow-necked mouse (A. flavicollis). These findings had no connection with the epizootological situation in the nearby livestock. M. fortuitum was isolated from the organs of the common vole (M. arvalis) caught in a field within easy reach of a swine breeding herd. M. fortuitum was also identified in the lymph nodes and droppings of this swine herd, as well as in the straw, scrapings from the floor of stalls, troughs and banisters, as well as from larvae and imagoes of dipterous insects. These results demonstrate the possibility that insectivores and small rodents can spread the causative agents of mycobacteria in wild and domestic animals.

  10. Rodent Models of Genetic Contributions to Motivation to Abuse Alcohol

    PubMed Central

    Crabbe, John C.

    2016-01-01

    The distinction between alcohol use (normative) and abuse (unfortunately common) implies dysregulation of motivation directed toward the drug. Genetic contributions to abuse risk are mediated through personality differences, other predispositions to drink excessively, and differences in sensitivity to the acute and chronic consequences of the drug. How to assess motivation in laboratory animals is not straightforward but risk factors for and consequences of alcohol abuse can be modeled with reasonable fidelity in laboratory rodents. Remarkably few rodent studies focus on the genetic contributions to alcohol’s reinforcing value: almost all examine preferential drinking of unflavored alcohol over water. Such studies will likely never avoid the confounding role of taste preferences and most often yield intake levels insufficient to yield a pharmacologically significant blood alcohol level. Genotypes that avoid alcohol probably do so based on pre-ingestive sensory cues; however, post-ingestive consequences are also important. Thus, the quest for improved measures of reinforcing value continues. We have genetic differences aplenty, but still lack evidence that any genotype will readily self-administer alcohol to the devastating extent that many alcoholics will. Encouraging results that are emerging include improved behavioral methods for elevating alcohol intake and inferring alcohol reinforcement, as well as new genetic animal models. Several ingenious assays to index alcohol’s motivational effects have been used extensively. Alcoholic drinking that attempts to prevent or to alleviate withdrawal symptoms has been modeled. Another characteristic of alcoholic drinking is its persistence despite abundant evidence to the drinker of the damaging effects of the excessive drinking on work, relationships, and/or health. Modeling such persistence in rodents has been uncommon to date. New genetic animal models include lines of mice selectively bred for chronic high drinking

  11. Default-mode-like network activation in awake rodents.

    PubMed

    Upadhyay, Jaymin; Baker, Scott J; Chandran, Prasant; Miller, Loan; Lee, Younglim; Marek, Gerard J; Sakoglu, Unal; Chin, Chih-Liang; Luo, Feng; Fox, Gerard B; Day, Mark

    2011-01-01

    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.

  12. Unintentional wildlife poisoning and proposals for sustainable management of rodents.

    PubMed

    Coeurdassier, Michael; Riols, Romain; Decors, Anouk; Mionnet, Aymeric; David, Fabienne; Quintaine, Thomas; Truchetet, Denis; Scheifler, Renaud; Giraudoux, Patrick

    2014-04-01

    In Europe, bromadiolone, an anticoagulant rodenticide authorized for plant protection, may be applied intensively in fields to control rodents. The high level of poisoning of wildlife that follows such treatments over large areas has been frequently reported. In France, bromadiolone has been used to control water voles (Arvicola terrestris) since the 1980s. Both regulation and practices of rodent control have evolved during the last 15 years to restrict the quantity of poisoned bait used by farmers. This has led to a drastic reduction of the number of cases of poisoned wildlife reported by the French surveillance network SAGIR. During the autumn and winter 2011, favorable weather conditions and high vole densities led to the staging of several hundreds of Red Kites (Milvus milvus) in the Puy-de-Dôme department (central France). At the same time, intensive treatments with bromadiolone were performed in this area. Although no misuse has been mentioned by the authorities following controls, 28 Red Kites and 16 Common Buzzards (Buteo buteo) were found dead during surveys in November and December 2011. For all these birds, poisoning by bromadiolone as the main cause of death was either confirmed or highly suspected. Other observations suggest a possible impact of bromadiolone on the breeding population of Red Kites in this area during the spring 2011. French regulation of vole control for plant protection is currently under revision, and we believe this event calls for more sustainable management of rodent outbreaks. Based on large-scale experiments undertaken in eastern France, we propose that direct control of voles at low density (with trapping or limited chemical treatments) and mechanical destruction of vole tunnels, mole control, landscape management, and predator fostering be included in future regulation because such practices could help resolve conservation and agricultural issues.

  13. Behavioral effects of developmental methylmercury drinking water exposure in rodents.

    PubMed

    Bisen-Hersh, Emily B; Farina, Marcelo; Barbosa, Fernando; Rocha, Joao B T; Aschner, Michael

    2014-04-01

    Early methylmercury (MeHg) exposure can have long-lasting consequences likely arising from impaired developmental processes, the outcome of which has been exposed in several longitudinal studies of affected populations. Given the large number of newborns at an increased risk of learning disabilities associated with in utero MeHg exposure, it is important to study neurobehavioral alterations using ecologically valid and physiologically relevant models. This review highlights the benefits of using the MeHg drinking water exposure paradigm and outlines behavioral outcomes arising from this procedure in rodents. Combination treatments that exacerbate or ameliorate MeHg-induced effects, and possible molecular mechanisms underlying behavioral impairment are also discussed.

  14. Ultraviolet regulation of neuroendocrine and circadian physiology in rodents.

    PubMed

    Brainard, G C; Barker, F M; Hoffman, R J; Stetson, M H; Hanifin, J P; Podolin, P L; Rollag, M D

    1994-06-01

    UV wavelengths can regulate neuroendocrine and circadian responses in some rodent species. Appropriately timed UV exposures can block the short photoperiod-induced collapse of the reproductive system, cause a rapid suppression of nocturnal melatonin synthesis, regulate melatonin rhythms and phase shift wheel running rhythms. These biological effects of UV are not dependent on the Harderian gland or melanin in the eye, but appear to be related to the degree of transmission through the ocular lens. Such results are consistent with the hypothesis that elements in the retina can transduce UV stimuli for circadian and neuroendocrine regulation.

  15. High field magnetic resonance imaging of rodents in cardiovascular research.

    PubMed

    Vanhoutte, Laetitia; Gerber, Bernhard L; Gallez, Bernard; Po, Chrystelle; Magat, Julie; Jean-Luc, Balligand; Feron, Olivier; Moniotte, Stéphane

    2016-07-01

    Transgenic and gene knockout rodent models are primordial to study pathophysiological processes in cardiovascular research. Over time, cardiac MRI has become a gold standard for in vivo evaluation of such models. Technical advances have led to the development of magnets with increasingly high field strength, allowing specific investigation of cardiac anatomy, global and regional function, viability, perfusion or vascular parameters. The aim of this report is to provide a review of the various sequences and techniques available to image mice on 7-11.7 T magnets and relevant to the clinical setting in humans. Specific technical aspects due to the rise of the magnetic field are also discussed.

  16. Nonhuman gamblers: lessons from rodents, primates, and robots

    PubMed Central

    Paglieri, Fabio; Addessi, Elsa; De Petrillo, Francesca; Laviola, Giovanni; Mirolli, Marco; Parisi, Domenico; Petrosino, Giancarlo; Ventricelli, Marialba; Zoratto, Francesca; Adriani, Walter

    2014-01-01

    The search for neuronal and psychological underpinnings of pathological gambling in humans would benefit from investigating related phenomena also outside of our species. In this paper, we present a survey of studies in three widely different populations of agents, namely rodents, non-human primates, and robots. Each of these populations offers valuable and complementary insights on the topic, as the literature demonstrates. In addition, we highlight the deep and complex connections between relevant results across these different areas of research (i.e., cognitive and computational neuroscience, neuroethology, cognitive primatology, neuropsychiatry, evolutionary robotics), to make the case for a greater degree of methodological integration in future studies on pathological gambling. PMID:24574984

  17. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.; Taylor, Larry

    2008-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. NASA established the Lunar Airborne Dust Toxicity Advisory Group (LADTAG) to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Because the toxicity of lunar dust is not known, LADTAG has recommended investigating its toxicity in the lungs of laboratory animals. After receiving this recommendation, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust in exposed rodents. The rodent pulmonary toxicity studies proposed here are the same as those proposed by the LADTAG. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal instillation (ITI). This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. We succeeded in completing an ITI study on JSC-1 lunar dust simulant in mice (Lam et al., Inhalation Toxicology 14:901-916, 2002, and Inhalation Toxicology 14: 917-928, 2002), and have conducted a pilot ITI study to examine the acute toxicity of an Apollo lunar (highland) dust sample. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies have been planned to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The ITI results will also be

  18. Rodent Habitat On ISS: Spaceflight Effects On Mouse Behavior

    NASA Technical Reports Server (NTRS)

    Ronca, A. E.; Moyer, E. L.; Talyansky, Y.; Padmanabhan, S.; Choi, S.; Gong, C.; Globus, R. K.

    2016-01-01

    The NASA Decadal Survey (2011), Recapturing a Future for Space Exploration: Life and Physical Sciences Research for a New Era, emphasized the importance of expanding NASA life sciences research to long duration, rodent experiments on the International Space Station (ISS). To accomplish this objective, flight hardware, operations, and science capabilities supporting mouse studies in space were developed at NASA Ames Research Center. The first flight experiment carrying mice, Rodent Research Hardware and Operations Validation (Rodent Research-1), was launched on Sept 21, 2014 in an unmanned Dragon Capsule, SpaceX4, exposing the mice to a total of 37 days in space. Ground control groups were maintained in environmental chambers at Kennedy Space Center. Mouse health and behavior were monitored for the duration of the experiment via video streaming. Here we present behavioral analysis of two groups of five C57BL/6 female adult mice viewed via fixed camera views compared with identically housed Ground Controls. Flight (Flt) and Ground Control (GC) mice exhibited the same range of behaviors, including eating, drinking, exploratory behavior, self- and allo-grooming, and social interactions at similar or greater levels of occurrence. Mice propelled themselves freely and actively throughout the Habitat using their forelimbs to push off or by floating from one cage area to another, and they quickly learned to anchor themselves using tails and/or paws. Overall activity was greater in Flt as compared to GC mice, with spontaneous ambulatory behavior including the development of organized ‘circling’ or ‘race-tracking’ behavior that emerged within the first few days of flight and encompassed the primary dark cycle activity for the remainder of the experiment. We quantified the bout frequency, duration and rate of circling with respect to characteristic behaviors observed in the varying stages of the progressive development of circling: flipping utilizing two sides of the

  19. Rodent spinal cord injury models for studies of axon regeneration.

    PubMed

    Steward, Oswald; Willenberg, Rafer

    2017-01-01

    For over a century, axon regeneration has been considered the Holy Grail for spinal cord injury (SCI) repair. Although there are other factors that could contribute to improving function, restoring the long motor and sensory tracts that are interrupted by SCI has the greatest potential for actually reversing paralysis, restoring the brain's control of autonomic functions mediated by sympathetic and parasympathetic circuits of the spinal cord and restoring sensation. Accordingly and in keeping with the overall theme of this special issue, this review focuses narrowly on rodent SCI models for studies of axon regeneration.

  20. Diagnostic Imaging of Dental Disease in Pet Rabbits and Rodents.

    PubMed

    Capello, Vittorio

    2016-09-01

    Diagnostic imaging techniques are of paramount importance for dentistry and oral disorders of rabbits, rodents, and other exotic companion mammals. Aside from standard radiography, stomatoscopy is a complementary tool allowing a thorough and detailed inspection of the oral cavity. Computed tomography (CT) generates multiple 2-dimensional views and 3-dimensional reconstructions providing superior diagnostic accuracy also useful for prognosis and treatment of advanced dental disease and its related complications. MRI is a diagnostic imaging technique additional to CT used primarily to enhance soft tissues, including complex odontogenic abscesses.

  1. Ecologic studies of rodent reservoirs: their relevance for human health.

    PubMed Central

    Mills, J. N.; Childs, J. E.

    1998-01-01

    Within the past few years, the number of "new" human diseases associated with small-mammal reservoirs has increased dramatically, stimulating renewed interest in reservoir ecology research. A consistent, integrative approach to such research allows direct comparisons between studies, contributes to the efficient use of resources and data, and increases investigator safety. We outline steps directed toward understanding vertebrate host ecology as it relates to human disease and illustrate the relevance of each step by using examples from studies of hosts associated with rodent-borne hemorrhagic fever viruses. PMID:9866729

  2. Survey on wild rodents for endoparasites in Iwate Prefecture, Japan.

    PubMed

    Ito, Megumi; Itagaki, Tadashi

    2003-10-01

    Wild rodents (58 Apodemus speciosus, 29 A. argenteus and 7 Microtus montebelli) were surveyed for endoparasites in Iwate Prefecture, Japan, from October to December 1995 and from April to October 1996. Two trematodes (Echinostoma macrorchis, Plagiorchis muris), 4 or more cestodes (Hymenolepis diminuta, Raillietina coreensis, Cladothyridium spp., Cysticercus fasciolaris), 12 nematodes (Carolinensis minutus, Eucoleus sp., Heligmosomoides kurilensis, H. protobullosus, H. speciosus, Heterakis spumosa, Rhabditis (Pelodera) orbitalis, Rictularia cristata, Syphacia emileromani, S. frederici, S. montana, Trichuris sp.) and 3 protozoans (Giardia sp., Trichomonas sp., Trypanosoma sp.) were identified. The two species of Apodemus were similar to each other, but they were extremely different from M. montebelli in parasite fauna.

  3. The water economy of South American desert rodents: from integrative to molecular physiological ecology.

    PubMed

    Bozinovic, Francisco; Gallardo, Pedro

    2006-01-01

    Rodents from arid and semi-arid habitats live under conditions where the spatial and temporal availability of free water is limited, or scarce, thus forcing these rodents to deal with the problem of water conservation. The response of rodents to unproductive desert environments and water deficits has been intensively investigated in many deserts of the world. However, current understanding of the cellular, systemic and organismal physiology of water economy relies heavily on short-term, laboratory-oriented experiments, which usually focus on responses at isolated levels of biological organization. In addition, studies in small South American mammals are scarce. Indeed xeric habitats have existed in South America for a long time and it is intriguing why present day South American desert rodents do not show the wide array of adaptive traits to desert life observed for rodents on other continents. Several authors have pointed out that South American desert rodents lack physiological and energetic specialization for energy and water conservation, hypothesizing that their success is based more on behavioral and ecological strategies. We review phenotypic flexibility and physiological diversity in water flux rate, urine osmolality, and expression of water channels in South American desert-dwelling rodents. As far as we know, this is the first review of integrative studies at cellular, systemic and organismal levels. Our main conclusion is that South American desert rodents possess structural as well as physiological systems for water conservation, which are as remarkable as those found in "classical" rodents inhabiting other desert areas of the world.

  4. Multiple co-infections of rodents with hantaviruses, Leptospira, and Babesia in Croatia.

    PubMed

    Tadin, Ante; Turk, Nenad; Korva, Miša; Margaletić, Josip; Beck, Relja; Vucelja, Marko; Habuš, Josipa; Svoboda, Petra; Zupanc, Tatjana Avšič; Henttonen, Heikki; Markotić, Alemka

    2012-05-01

    Hantaviruses, Leptospira spp., and Babesia spp. are rodent-borne pathogens present worldwide. We studied multiple co-infections of small rodents in Croatia with all three pathogens. Twenty-eight Apodemus flavicollis and 16 Myodes glareolus were tested for the presence of hantavirus RNA by real-time RT-PCR, Leptospira strains by renoculture method and Babesia DNA by PCR. Anti-hantavirus antibodies and anti-Leptospira antibodies were detected by serological methods. Very high infection rates with each pathogen were found in A. flavicollis: 20 of 28 rodents (71%) were infected with Dobrava virus, 13 rodents (46%) were infected with Leptospira, and 5 rodents (18%) were infected with Babesia. Multiple co-infections with all three pathogens were found in 3 of 28 (11%) A. flavicollis animals, suggesting that the same rodent host can be infected with several pathogens at the same time. Dual infections with both hantaviruses and Leptospira were found in 7 of 44 rodents (16%), with hantaviruses and Babesia in 2 rodents (5%), and double infection with both Leptospira and Babesia were found in 1 rodent (2%). Since hantaviruses, Leptospira, and Babesia have similar geographical distributions, it is to be expected that in other parts of the world multiple co-infections, representing a serious threat to public health, can be found.

  5. Characteristics associated with contact with rodents in, around, and outside homes in Khon Kaen Province, Thailand.

    PubMed

    Suwannarong, Kanokwan; Chapman, Robert S

    2015-04-01

    Rodents are an important reservoir for zoonotic diseases. To enhance the evidence on the human-rodent interface, this cross-sectional study was conducted in 2011 to investigate characteristics associated with rodent contact in Khon Kaen Province, Thailand. A standardized, interviewer-administered questionnaire elicited information from 201 adults (101 males and 100 females). Overall, 86.6% of participants reported encountering or seeing evidence of rodents in or near the home, whereas 57.2% encountered rodents while working with crops. Encountering rodents in or near the home was positively associated with the number of agricultural activities, whereas encountering rodents during crop work was positively associated with perceiving that disease can be acquired from rodents, the number of food crops grown, the number of agricultural activities, and living in a house with wooden walls. Surprisingly, neither outcome was associated appreciably with gender, age, or setting (urban, forest, or agricultural). These results provide information on the potential risk of rodent-borne zoonoses; this evidence has implications for risk communication strategies in this province and likely elsewhere.

  6. Effects of bleeding nonanesthetized wild rodents on handling mortality and subsequent recapture.

    PubMed

    Douglass, R J; Kuenzi, A J; Wilson, T; Van Horne, R C

    2000-10-01

    Handling mortality and recapture rates of wild rodents that were bled from the retroorbital capillary plexus without anesthesia were assessed. In 9,670 captures of seven species of rodents from 1994 through 1998, we found no difference in handling mortality in bled mice compared to those from trapping grids where mice were not bled. Recapture rates of rodents on control (non-bleeding grids) and rodents on bleeding grids was not significantly different for any species. We conclude that bleeding in the absence of anesthesia does not affect immediate mortality or subsequent recapture.

  7. Helminth parasite species richness in rodents from Southeast Asia: role of host species and habitat.

    PubMed

    Palmeirim, Marta; Bordes, Frédéric; Chaisiri, Kittipong; Siribat, Praphaiphat; Ribas, Alexis; Morand, Serge

    2014-10-01

    Southeast Asia is a biodiversity hotspot that harbours many species of rodents, including some that live in close contact with humans. They host helminth parasites, some of which are of zoonotic importance. It is therefore important to understand the factors that influence the richness of the helminths parasitizing rodents. The specific objectives of this study were to evaluate rodent species as a factor determining helminth richness in rodent assemblages, to identify the major rodent helminth reservoir species and to explore the influence of habitat on helminth richness. We estimated helminth species richness using a large dataset of 18 rodent species (1,651 individuals) originating from Southeast Asia and screened for helminth parasites. The use of an unbiased estimator shows that the helminth species richness varies substantially among rodent species and across habitats. We confirmed this pattern by investigating the number of helminth species per individual rodent in all rodent species, and specifically in the two mitochondrial lineages Rattus tanezumi and R. tanezumi R3, which were captured in all habitats.

  8. Prediction of rodent nongenotoxic carcinogenesis: evaluation of biochemical and tissue changes in rodents following exposure to nine nongenotoxic NTP carcinogens.

    PubMed

    Elcombe, Clifford R; Odum, Jenny; Foster, John R; Stone, Susan; Hasmall, Susan; Soames, Anthony R; Kimber, Ian; Ashby, John

    2002-04-01

    We studied nine presumed nongenotoxic rodent carcinogens, as defined by the U.S. National Toxicology Program (NTP), to determine their ability to induce acute or subacute biochemical and tissue changes that may act as useful predictors of nongenotoxic rodent carcinogenesis. The chemicals selected included six liver carcinogens (two of which are peroxisome proliferators), three thyroid gland carcinogens, and four kidney carcinogens. We administered the chemicals (diethylhexyl phthalate, cinnamyl anthranilate, chlorendic acid, 1,4-dichlorobenzene, monuron, ethylene thiourea, diethyl thiourea, trimethyl thiourea, and d-limonene to the same strains of mice and rats used in the original NTP bioassays (nine chemicals to rats and seven to mice). Selected tissues (liver, thyroid gland, and kidney) were collected from groups of animals at 7, 28, and 90 days for evaluation. Tissue changes selected for study were monitored for all of the test groups, irrespective of the specificity of the carcinogenic responses observed in those tissues. This allowed us to assess both the carcinogen specificity and the carcinogen sensitivity of the events being monitored. We studied relative weight, cell labeling indices, and pathologic changes such as hypertrophy in all tissues; a range of cytochrome P450 enzymes and palmitoyl coenzyme A oxidase in the liver; changes in the levels of plasma total triiodothyronine, total thyroxine, and thyroid-stimulating hormone (TSH) as markers of thyroid gland function; and hyaline droplet formation, tubular basophilia, and the formation of granular casts in the kidney. There were no single measurements that alerted specifically to the carcinogenicity of the agents to the rodent liver, thyroid gland, or kidney. However, in the majority of cases, the chemical induction of cancer in a tissue was preceded by a range of biochemical/morphologic changes, most of which were moderately specific for a carcinogenic outcome, and some of which were highly specific for

  9. Detection and characterization of a novel polyomavirus in wild rodents.

    PubMed

    Orba, Yasuko; Kobayashi, Shintaro; Nakamura, Ichiro; Ishii, Akihiro; Hang'ombe, Bernard M; Mweene, Aaron S; Thomas, Yuka; Kimura, Takashi; Sawa, Hirofumi

    2011-04-01

    To investigate polyomavirus infection in wild rodents, we analysed DNA samples from the spleens of 100 wild rodents from Zambia using a broad-spectrum PCR-based assay. A previously unknown polyomavirus genome was identified in a sample from a multimammate mouse (Mastomys species) and the entire viral genome of 4899 bp was subsequently sequenced. This viral genome contained potential ORFs for the capsid proteins, VP1, VP2 and VP3, and early proteins, small t antigen and large T antigen. Phylogenetic analysis showed that it was a novel member of the family Polyomaviridae, and thus the virus was tentatively named mastomys polyomavirus. After transfection of the viral genome into several mammalian cell lines, transient expression of the VP1 and large T antigen proteins was confirmed by immunoblotting and immunocytochemical analyses. Comparison of large T antigen function in mastomys polyomavirus with that in rhesus monkey polyomavirus SV40 and human polyomavirus JC virus revealed that the large T antigen from mastomys polyomavirus interacted with the tumour suppressor protein pRb, but not with p53.

  10. Visual landmarks facilitate rodent spatial navigation in virtual reality environments

    PubMed Central

    Youngstrom, Isaac A.; Strowbridge, Ben W.

    2012-01-01

    Because many different sensory modalities contribute to spatial learning in rodents, it has been difficult to determine whether spatial navigation can be guided solely by visual cues. Rodents moving within physical environments with visual cues engage a variety of nonvisual sensory systems that cannot be easily inhibited without lesioning brain areas. Virtual reality offers a unique approach to ask whether visual landmark cues alone are sufficient to improve performance in a spatial task. We found that mice could learn to navigate between two water reward locations along a virtual bidirectional linear track using a spherical treadmill. Mice exposed to a virtual environment with vivid visual cues rendered on a single monitor increased their performance over a 3-d training regimen. Training significantly increased the percentage of time avatars controlled by the mice spent near reward locations in probe trials without water rewards. Neither improvement during training or spatial learning for reward locations occurred with mice operating a virtual environment without vivid landmarks or with mice deprived of all visual feedback. Mice operating the vivid environment developed stereotyped avatar turning behaviors when alternating between reward zones that were positively correlated with their performance on the probe trial. These results suggest that mice are able to learn to navigate to specific locations using only visual cues presented within a virtual environment rendered on a single computer monitor. PMID:22345484

  11. Morphology captures diet and locomotor types in rodents

    PubMed Central

    Fisher, Diana O.; Schweizer, Manuel

    2017-01-01

    To understand the functional meaning of morphological features, we need to relate what we know about morphology and ecology in a meaningful, quantitative framework. Closely related species usually share more phenotypic features than distant ones, but close relatives do not necessarily have the same ecologies. Rodents are the most diverse group of living mammals, with impressive ecomorphological diversification. We used museum collections and ecological literature to gather data on morphology, diet and locomotion for 208 species of rodents from different bioregions to investigate how morphological similarity and phylogenetic relatedness are associated with ecology. After considering differences in body size and shared evolutionary history, we find that unrelated species with similar ecologies can be characterized by a well-defined suite of morphological features. Our results validate the hypothesized ecological relevance of the chosen traits. These cranial, dental and external (e.g. ears) characters predicted diet and locomotion and showed consistent differences among species with different feeding and substrate use strategies. We conclude that when ecological characters do not show strong phylogenetic patterns, we cannot simply assume that close relatives are ecologically similar. Museum specimens are valuable records of species' phenotypes and with the characters proposed here, morphology can reflect functional similarity, an important component of community ecology and macroevolution. PMID:28280593

  12. Molecular detection of bacterial contamination in gnotobiotic rodent units

    PubMed Central

    Packey, Christopher D; Shanahan, Michael T; Manick, Sayeed; Bower, Maureen A; Ellermann, Melissa; Tonkonogy, Susan L; Carroll, Ian M; Sartor, R Balfour

    2013-01-01

    Gnotobiotic rodents provide an important technique to study the functional roles of commensal bacteria in host physiology and pathophysiology. To ensure sterility, these animals must be screened frequently for contamination. The traditional screening approaches of culturing and Gram staining feces have inherent limitations, as many bacteria are uncultivable and fecal Gram stains are difficult to interpret. Thus, we developed and validated molecular methods to definitively detect and identify contamination in germ-free (GF) and selectively colonized animals. Fresh fecal pellets were collected from rodents housed in GF isolators, spontaneously contaminated ex-GF isolators, selectively colonized isolators and specific pathogen-free (SPF) conditions. DNA isolated from mouse and rat fecal samples was amplified by polymerase chain reaction (PCR) and subjected to quantitative PCR (qPCR) using universal primers that amplify the 16S rRNA gene from all bacterial groups. PCR products were sequenced to identify contaminating bacterial species. Random amplification of polymorphic DNA (RAPD) PCR profiles verified bacterial inoculation of selectively colonized animals. These PCR techniques more accurately detected and identified GF isolator contamination than current standard approaches. These molecular techniques can be utilized to more definitively screen GF and selectively colonized animals for bacterial contamination when Gram stain and/or culture results are un-interpretable or inconsistent. PMID:23887190

  13. Modelling cognitive affective biases in major depressive disorder using rodents.

    PubMed

    Hales, Claire A; Stuart, Sarah A; Anderson, Michael H; Robinson, Emma S J

    2014-10-01

    Major depressive disorder (MDD) affects more than 10% of the population, although our understanding of the underlying aetiology of the disease and how antidepressant drugs act to remediate symptoms is limited. Major obstacles include the lack of availability of good animal models that replicate aspects of the phenotype and tests to assay depression-like behaviour in non-human species. To date, research in rodents has been dominated by two types of assays designed to test for depression-like behaviour: behavioural despair tests, such as the forced swim test, and measures of anhedonia, such as the sucrose preference test. These tests have shown relatively good predictive validity in terms of antidepressant efficacy, but have limited translational validity. Recent developments in clinical research have revealed that cognitive affective biases (CABs) are a key feature of MDD. Through the development of neuropsychological tests to provide objective measures of CAB in humans, we have the opportunity to use 'reverse translation' to develop and evaluate whether similar methods are suitable for research into MDD using animals. The first example of this approach was reported in 2004 where rodents in a putative negative affective state were shown to exhibit pessimistic choices in a judgement bias task. Subsequent work in both judgement bias tests and a novel affective bias task suggest that these types of assay may provide translational methods for studying MDD using animals. This review considers recent work in this area and the pharmacological and translational validity of these new animal models of CABs.

  14. Comparative Analysis of Testis Protein Evolution in Rodents

    PubMed Central

    Turner, Leslie M.; Chuong, Edward B.; Hoekstra, Hopi E.

    2008-01-01

    Genes expressed in testes are critical to male reproductive success, affecting spermatogenesis, sperm competition, and sperm–egg interaction. Comparing the evolution of testis proteins at different taxonomic levels can reveal which genes and functional classes are targets of natural and sexual selection and whether the same genes are targets among taxa. Here we examine the evolution of testis-expressed proteins at different levels of divergence among three rodents, mouse (Mus musculus), rat (Rattus norvegicus), and deer mouse (Peromyscus maniculatus), to identify rapidly evolving genes. Comparison of expressed sequence tags (ESTs) from testes suggests that proteins with testis-specific expression evolve more rapidly on average than proteins with maximal expression in other tissues. Genes with the highest rates of evolution have a variety of functional roles including signal transduction, DNA binding, and egg–sperm interaction. Most of these rapidly evolving genes have not been identified previously as targets of selection in comparisons among more divergent mammals. To determine if these genes are evolving rapidly among closely related species, we sequenced 11 of these genes in six Peromyscus species and found evidence for positive selection in five of them. Together, these results demonstrate rapid evolution of functionally diverse testis-expressed proteins in rodents, including the identification of amino acids under lineage-specific selection in Peromyscus. Evidence for positive selection among closely related species suggests that changes in these proteins may have consequences for reproductive isolation. PMID:18689890

  15. Ancient DNA and the tropics: a rodent's tale

    PubMed Central

    Gutiérrez-García, Tania A.; Vázquez-Domínguez, Ella; Arroyo-Cabrales, Joaquín; Kuch, Melanie; Enk, Jacob; King, Christine; Poinar, Hendrik N.

    2014-01-01

    Most genetic studies of Holocene fauna have been performed with ancient samples from dry and cold regions, in which preservation of fossils is facilitated and molecular damage is reduced. Ancient DNA work from tropical regions has been precluded owing to factors that limit DNA preservation (e.g. temperature, hydrolytic damage). We analysed ancient DNA from rodent jawbones identified as Ototylomys phyllotis, found in Holocene and Late Pleistocene stratigraphic layers from Loltún, a humid tropical cave located in the Yucatan peninsula. We extracted DNA and amplified six short overlapping fragments of the cytochrome b gene, totalling 666 bp, which represents an unprecedented success considering tropical ancient DNA samples. We performed genetic, phylogenetic and divergence time analyses, combining sequences from ancient and modern O. phyllotis, in order to assess the ancestry of the Loltún samples. Results show that all ancient samples fall into a unique clade that diverged prior to the divergence of the modern O. phyllotis, supporting it as a distinct Pleistocene form of the Ototylomys genus. Hence, this rodent's tale suggests that the sister group to modern O. phyllotis arose during the Miocene–Pliocene, diversified during the Pleistocene and went extinct in the Holocene. PMID:24899682

  16. Chromosomal instability in rodents caused by pollution from Baikonur cosmodrome.

    PubMed

    Kolumbayeva, Saule; Begimbetova, Dinara; Shalakhmetova, Tamara; Saliev, Timur; Lovinskaya, Anna; Zhunusbekova, Benazir

    2014-09-01

    An assessment of the health status of ecosystems exposed to man-made pollution is a vital issue for many countries. Particularly it concerns the consequences of contamination caused by the activity of the space industry. Each rocket launch is accompanied by the introduction of parts of the rocket propellant into the environment. This study aims to scrutinize the effect of the components of rocket fuel on the induction of lipid peroxidation and chromosomal aberrations on rodents inhabiting the area exposed to pollution from Baikonur cosmodrome. The results showed the increase of the level of lipid hydroperoxide and malondialdehyde in the livers of Citellus pygmaeus Pallas and Mus musculus L., which indicates an augmentation of free radical activity and DNA damage. The cytogenetic analysis of bone marrow cells revealed that the frequency of chromosomal aberrations was a few times higher in the rodents from contaminated territory. The signs of oxidative stress and high level of chromosomal aberrations indicate the environmental impact of the cosmodrome, and its possible toxic and mutagenic effects on ecosystems.

  17. Spontaneous and transgenic rodent models of inflammatory bowel disease

    PubMed Central

    Jurjus, Abdo

    2015-01-01

    Inflammatory Bowel Disease (IBD) is a multifactorial disorder with many different putative influences mediating disease onset, severity, progression and diminution. Spontaneous natural IBD is classically expressed as Crohn's Disease (CD) and Ulcerative Colitis (UC) commonly found in primates; lymphoplasmocytic enteritis, eosinophilic gastritis and colitis, and ulcerative colitis with neuronal hyperplasia in dogs; and colitis in horses. Spontaneous inflammatory bowel disease has been noted in a number of rodent models which differ in genetic strain background, induced mutation, microbiota influences and immunopathogenic pathways. Histological lesions in Crohn's Disease feature noncaseating granulomatous inflammation while UC lesions typically exhibit ulceration, lamina propria inflammatory infiltrates and lack of granuloma development. Intestinal inflammation caused by CD and UC is also associated with increased incidence of intestinal neoplasia. Transgenic murine models have determined underlying etiological influences and appropriate therapeutic targets in IBD. This literature review will discuss current opinion and findings in spontaneous IBD, highlight selected transgenic rodent models of IBD and discuss their respective pathogenic mechanisms. It is very important to provide accommodation of induced putative deficits in activities of daily living and to assess discomfort and pain levels in the face of significant morbidity and/or mortality in these models. Epigenetic, environmental (microbiome, metabolome) and nutritional factors are important in IBD pathogenesis, and evaluating ways in which they influence disease expression represent potential investigative approaches with the greatest potential for new discoveries. PMID:26155200

  18. Management of Rodent Exposure and Allergy in the Pediatric Population

    PubMed Central

    Matsui, Elizabeth C.

    2013-01-01

    Although rodent allergy has long been recognized as an occupational disease, it has only been in the past decade that it has been recognized as a community-based disease that affects children. Most homes in the US have detectable mouse allergen, but the concentrations in inner-city homes are orders of magnitude higher than those found in suburban homes. Home mouse allergen exposure has been linked to sensitization to mouse, and children with asthma who are both sensitized and exposed to high mouse allergen concentrations at home are at greater risk for symptoms, exacerbations and reduced lung function. Rat allergen is found primarily in inner-city homes and has also been linked to asthma morbidity among sensitized children. The objective of this review is to summarize the scientific literature on rodents and their allergens, the effects of exposure to these allergens on allergic respiratory disease, and to make recommendations, based on this evidence base, for the evaluation and management of mouse allergy in the pediatric population. PMID:23912589

  19. Sero-Prevalence of Rodent Pathogens in India.

    PubMed

    Manjunath, Shrruthi; Kulkarni, Prachet G; Nagavelu, Krishnaveni; Samuel, Rosa J; Srinivasan, Sandhya; Ramasamy, Nandhini; Hegde, Nagendra R; Gudde, Ramachandra S

    2015-01-01

    Health monitoring is an integral part of laboratory animal quality standards. However, current or past prevalence data as well as regulatory requirements dictate the frequency, type and the expanse of health monitoring. In an effort to understand the prevalence of rodent pathogens in India, a preliminary study was carried out by sero-epidemiology. Sera samples obtained from 26 public and private animal facilities were analyzed for the presence of antibodies against minute virus of mice (MVM), ectromelia virus (ECTV), lymphocytic choriomeningitis virus (LCMV), mouse hepatitis virus (MHV), Sendai virus (SeV), and Mycoplasma pulmonis in mice, and SeV, rat parvo virus (RPV), Kilham's rat virus (KRV) and sialodacryoadenitis virus (SDAV) in rats, by sandwich ELISA. It was observed that MHV was the most prevalent agent followed by Mycoplasma pulmonis and MVM in mice, and SDAV followed by RPV were prevalent in rats. On the other hand, none of the samples were positive for ECTV in mice, or SeV or KRV in rats. Multiple infections were common in both mice and rats. The incidence of MHV and Mycoplasma pulmonis was higher in facilities maintained by public organizations than in vivaria of private organizations, although the difference was not statistically different. On the other hand the prevalence of rodent pathogens was significantly higher in the northern part of India than in the South. These studies form the groundwork for detailed sero-prevalence studies which should further lay the foundations for country-specific guidelines for health monitoring of laboratory animals.

  20. Emmonsiosis of wild rodents and insectivores in Czechland.

    PubMed

    Hubálek, Z

    1999-04-01

    Adiaspores of the fungus Emmonsia crescens were detected microscopically in the lung tissue of 13% of 10.081 small mammals belonging to 24 species examined in 14 areas of the Czech Republic between 1986 and 1997; 441/1.934 (23%) Clethrionomys glareolus, 1/6 (17%) Arvicola terrestris, 357/2.172 (16%) Apodemus flavicollis, 220/1.981 (11%). A sylvaticus, 23/265 (9%) A. microps, 11/81 (14%) Microtus subterraneus, 93/1.275 (7%) M. arvalis, 98/1.439 (7%) M. agrestis, 1/3 (33%) Ondatra zibethicus, 1/1 Cricetus cricetus, 1/20 (5%) Crocidura suaveolens, 2/40 (5%) Neomys fodiens, and 13/529 (2%) Sorex araneus were infected. Emmonsiosis was not recorded among the species of rodents that do not build their nests in the soil (Muscardinus avellanarius, Micromys minutus, Mus musculus, Rattus norvegicus). The overall prevalence of emmonsiosis was significantly higher in adult (19%) than in juvenile (7%) mammals, and in rodents (13%, and 20% in adults) than in insectivores (2%, and 4% in adults). The frequency of infected mammals also varied according to geographic area, altitude, habitat, and season.

  1. Genome Diversification Mechanism of Rodent and Lagomorpha Chemokine Genes

    PubMed Central

    Shibata, Kanako; Yoshie, Osamu; Tanase, Sumio

    2013-01-01

    Chemokines are a large family of small cytokines that are involved in host defence and body homeostasis through recruitment of cells expressing their receptors. Their genes are known to undergo rapid evolution. Therefore, the number and content of chemokine genes can be quite diverse among the different species, making the orthologous relationships often ambiguous even between closely related species. Given that rodents and rabbit are useful experimental models in medicine and drug development, we have deduced the chemokine genes from the genome sequences of several rodent species and rabbit and compared them with those of human and mouse to determine the orthologous relationships. The interspecies differences should be taken into consideration when experimental results from animal models are extrapolated into humans. The chemokine gene lists and their orthologous relationships presented here will be useful for studies using these animal models. Our analysis also enables us to reconstruct possible gene duplication processes that generated the different sets of chemokine genes in these species. PMID:23991422

  2. Causal evidence between monsoon and evolution of rhizomyine rodents

    PubMed Central

    López-Antoñanzas, Raquel; Knoll, Fabien; Wan, Shiming; Flynn, Lawrence J.

    2015-01-01

    The modern Asian monsoonal systems are currently believed to have originated around the end of the Oligocene following a crucial step of uplift of the Tibetan-Himalayan highlands. Although monsoon possibly drove the evolution of many mammal lineages during the Neogene, no evidence thereof has been provided so far. We examined the evolutionary history of a clade of rodents, the Rhizomyinae, in conjunction with our current knowledge of monsoon fluctuations over time. The macroevolutionary dynamics of rhizomyines were analyzed within a well-constrained phylogenetic framework coupled with biogeographic and evolutionary rate studies. The evolutionary novelties developed by these rodents were surveyed in parallel with the fluctuations of the Indian monsoon so as to evaluate synchroneity and postulate causal relationships. We showed the existence of three drops in biodiversity during the evolution of rhizomyines, all of which reflected elevated extinction rates. Our results demonstrated linkage of monsoon variations with the evolution and biogeography of rhizomyines. Paradoxically, the evolution of rhizomyines was accelerated during the phases of weakening of the monsoons, not of strengthening, most probably because at those intervals forest habitats declined, which triggered extinction and progressive specialization toward a burrowing existence. PMID:25759260

  3. Molecular neuroimaging in rodents: assessing receptor expression and function.

    PubMed

    Mueggler, Thomas; Baltes, Christof; Rudin, Markus

    2009-11-01

    Multimodal non-invasive neuroimaging in rodents constitutes an attractive tool for studying neurobiological processes in vivo. At present, imaging studies of brain anatomy and function as well as the investigation of structure-function relationships belong to the standard repertoire of neuroscientists. Molecular imaging adds a new perspective. The mapping of the receptor distribution and receptor occupancy can nowadays be complemented by specific readouts of receptor function either by visualizing the activity of signaling pathways or mapping the physiological consequences of receptor stimulation. Molecular information is obtained through the use of imaging probes that combine a target-specific ligand with a reporter moiety that generates a signal that can be detected from outside the body. For imaging probes targeting the central nervous system, penetration of the intact blood-brain barrier constitutes a major hurdle. Molecular imaging generates specific information and therefore has a large potential for disease phenotyping (diagnostics), therapy development and monitoring of treatment response. Molecular imaging is still in its infancy and major developments in imaging technology, probe design and data analysis are required in order to make an impact. Rodent molecular neuroimaging will play an important role in the development of these tools.

  4. Spatial memory tasks in rodents: what do they model?

    PubMed

    Morellini, Fabio

    2013-10-01

    The analysis of spatial learning and memory in rodents is commonly used to investigate the mechanisms underlying certain forms of human cognition and to model their dysfunction in neuropsychiatric and neurodegenerative diseases. Proper interpretation of rodent behavior in terms of spatial memory and as a model of human cognitive functions is only possible if various navigation strategies and factors controlling the performance of the animal in a spatial task are taken into consideration. The aim of this review is to describe the experimental approaches that are being used for the study of spatial memory in rats and mice and the way that they can be interpreted in terms of general memory functions. After an introduction to the classification of memory into various categories and respective underlying neuroanatomical substrates, I explain the concept of spatial memory and its measurement in rats and mice by analysis of their navigation strategies. Subsequently, I describe the most common paradigms for spatial memory assessment with specific focus on methodological issues relevant for the correct interpretation of the results in terms of cognitive function. Finally, I present recent advances in the use of spatial memory tasks to investigate episodic-like memory in mice.

  5. Tests and models of nociception and pain in rodents.

    PubMed

    Barrot, M

    2012-06-01

    Nociception and pain is a large field of both neuroscience and medical research. Over time, various tests and models were developed in rodents to provide tools for fundamental and translational research on the topic. Tests using thermal, mechanical, and chemical stimuli, measures of hyperalgesia and allodynia, models of inflammatory or neuropathic pain, constitute a toolbox available to researchers. These tests and models allowed rapid progress on the anatomo-molecular basis of physiological and pathological pain, even though they have yet to translate into new analgesic drugs. More recently, a growing effort has been put forth trying to assess pain in rats or mice, rather than nociceptive reflexes, or at studying complex states affected by chronic pain. This aids to further improve the translational value of preclinical research in a field with balanced research efforts between fundamental research, preclinical work, and human studies. This review describes classical tests and models of nociception and pain in rodents. It also presents some recent and ongoing developments in nociceptive tests, recent trends for pain evaluation, and raises the question of the appropriateness between tests, models, and procedures.

  6. Genotoxic evaluation of pirfenidone using erythrocyte rodent micronucleus assay.

    PubMed

    Alcántar-Díaz, Blanca E; Gómez-Meda, Belinda C; Zúñiga-González, Guillermo M; Zamora-Perez, Ana L; González-Cuevas, Jaime; Alvarez-Rodríguez, Bertha A; Sánchez-Parada, María Guadalupe; García-Bañuelos, Jesús J; Armendáriz-Borunda, Juan

    2012-08-01

    Pirfenidone is a non-steroidal antifibrotic compound that has been proposed in clinical protocols and experimental studies as a pharmacological treatment for fibroproliferative diseases. The objective of this study was to determine the genotoxicity or cytotoxicity of three doses of pirfenidone using the micronuclei test in peripheral blood erythrocytes of rodent models. Pirfenidone was administered orally to Balb-C mice for 3 days, and also was administered topically to hairless Sprague Dawley rats during the final stage of gestation. Mice were sampled every 24 h over the course of 6 days; pregnant rats were sampled every 24 h during the last 6 days of gestation, and pups were sampled at birth. Blood smears were analyzed and the frequencies of micronucleated erythrocytes (MNEs), micronucleated polychromatic erythrocytes (MNPCEs), and the proportion of polychromatic erythrocytes (PCEs), were recorded in samples from mice, pregnant rats and rat neonates. Increases in MN frequencies (p<0.03) were noted only in the positive control groups. No genotoxic effects or decreased PCE values were observed neither in newborn rats transplacentally exposed to pirfenidone, or in two adult rodent models when pirfenidone was administered orally or topically.

  7. Relapsing fever group Borrelia in Southern California rodents.

    PubMed

    Nieto, Nathan C; Teglas, Mike B

    2014-09-01

    Wild rodent reservoir host species were surveyed prospectively for infection with Borrelia hermsii, the causative agent of tick-borne relapsing fever in the western United States. Trapping occurred during the summer of 2009-2012 at field sites surrounding Big Bear Lake, CA, a region where human infection has been reported for many years. Using quantitative polymerase chain reaction (qPCR), we tested 207 rodents from 11 species and found chipmunks (Tamias spp.) and a woodrat (Neotoma macrotis) infected. Chipmunks represented the majority of captures at these sites. Sixteen of the 207 (7.7%; CI = 4.6-12.4) animals were qPCR-positive for Borrelia spp. associated with relapsing fever, and of those, we obtained bacterial DNA sequences from eight. The phylogram made from these sequences depict a clear association with B. hermsii genomic group I. In addition, we identified an infection with Borrelia coriaceae in a Tamias merriami, a potentially nonpathogenic member of the tick-borne relapsing fever group. Our findings support the hypothesis that chipmunk species play an important role in the maintenance of Borrelia species that cause tick-borne relapsing fever in the western United States, and therefore the risk of infection to people.

  8. Causal evidence between monsoon and evolution of rhizomyine rodents.

    PubMed

    López-Antoñanzas, Raquel; Knoll, Fabien; Wan, Shiming; Flynn, Lawrence J

    2015-03-11

    The modern Asian monsoonal systems are currently believed to have originated around the end of the Oligocene following a crucial step of uplift of the Tibetan-Himalayan highlands. Although monsoon possibly drove the evolution of many mammal lineages during the Neogene, no evidence thereof has been provided so far. We examined the evolutionary history of a clade of rodents, the Rhizomyinae, in conjunction with our current knowledge of monsoon fluctuations over time. The macroevolutionary dynamics of rhizomyines were analyzed within a well-constrained phylogenetic framework coupled with biogeographic and evolutionary rate studies. The evolutionary novelties developed by these rodents were surveyed in parallel with the fluctuations of the Indian monsoon so as to evaluate synchroneity and postulate causal relationships. We showed the existence of three drops in biodiversity during the evolution of rhizomyines, all of which reflected elevated extinction rates. Our results demonstrated linkage of monsoon variations with the evolution and biogeography of rhizomyines. Paradoxically, the evolution of rhizomyines was accelerated during the phases of weakening of the monsoons, not of strengthening, most probably because at those intervals forest habitats declined, which triggered extinction and progressive specialization toward a burrowing existence.

  9. Causal evidence between monsoon and evolution of rhizomyine rodents

    NASA Astrophysics Data System (ADS)

    López-Antoñanzas, Raquel; Knoll, Fabien; Wan, Shiming; Flynn, Lawrence J.

    2015-03-01

    The modern Asian monsoonal systems are currently believed to have originated around the end of the Oligocene following a crucial step of uplift of the Tibetan-Himalayan highlands. Although monsoon possibly drove the evolution of many mammal lineages during the Neogene, no evidence thereof has been provided so far. We examined the evolutionary history of a clade of rodents, the Rhizomyinae, in conjunction with our current knowledge of monsoon fluctuations over time. The macroevolutionary dynamics of rhizomyines were analyzed within a well-constrained phylogenetic framework coupled with biogeographic and evolutionary rate studies. The evolutionary novelties developed by these rodents were surveyed in parallel with the fluctuations of the Indian monsoon so as to evaluate synchroneity and postulate causal relationships. We showed the existence of three drops in biodiversity during the evolution of rhizomyines, all of which reflected elevated extinction rates. Our results demonstrated linkage of monsoon variations with the evolution and biogeography of rhizomyines. Paradoxically, the evolution of rhizomyines was accelerated during the phases of weakening of the monsoons, not of strengthening, most probably because at those intervals forest habitats declined, which triggered extinction and progressive specialization toward a burrowing existence.

  10. The response of rodents to scent marks: four broad hypotheses.

    PubMed

    Ferkin, Michael H

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Many terrestrial mammals must be able to distinguish between the myriad of scent marks they encounter in order for them to facilitate or deter direct interactions with their scent donors. I review studies that examine how rodents, mainly meadow voles (Microtus pennsylvanicus), respond when they encounter the scent marks of conspecifics and heterospecifics, and how context, as well as the age and condition of senders and receivers, affect their responses. The review uses four broad hypotheses to discuss the response of rodents to scent marks. The four hypotheses are as follows: 1) Scent marks convey accurate information to the receiver about the sender's state and phenotype and genotype. 2) Scent marks are individually distinct. 3) The response of receivers to scent marks is flexible and would be modulated by the cognitive abilities of receivers. 4) Receivers respond to the information contained or conveyed by the scent mark in a manner that will increase their survival and fitness. The studies cited in this review show that scent marks signal accurate information about the sender's phenotype, genotype, and condition, which receivers use to distinguish among the scent marks of different conspecifics and heterospecifics, and by doing so, receivers tailor their response accordingly to increase their survival and fitness. Thus, the four broad hypotheses may serve as guide to increase our understanding of the response of receivers to scent marks and provide a conceptual framework for future research and the development of additional hypotheses.

  11. Holocene vegetation history from fossil rodent middens near Arequipa, Peru

    USGS Publications Warehouse

    Holmgren, C.A.; Betancourt, J.L.; Rylander, K.A.; Roque, J.; Tovar, O.; Zeballos, H.; Linares, E.; Quade, Jay

    2001-01-01

    Rodent (Abrocoma, Lagidium, Phyllotis) middens collected from 2350 to 2750 m elevation near Arequipa, Peru (16??S), provide an ???9600-yr vegetation history of the northern Atacama Desert, based on identification of >50 species of plant macrofossils. These midden floras show considerable stability throughout the Holocene, with slightly more mesophytic plant assemblages in the middle Holocene. Unlike the southwestern United States, rodent middens of mid-Holocene age are common. In the Arequipa area, the midden record does not reflect any effects of a mid-Holocene mega drought proposed from the extreme lowstand (100 m below modern levels, >6000 to 3500 yr B.P.) of Lake Titicaca, only 200 km east of Arequipa. This is perhaps not surprising, given other evidence for wetter summers on the Pacific slope of the Andes during the middle Holocene as well as the poor correlation of summer rainfall among modern weather stations in the central AndesAtacama Desert. The apparent difference in paleoclimatic reconstructions suggests that it is premature to relate changes observed during the Holocene to changes in El Nin??o Southern Oscillation modes. ?? 2001 University of Washington.

  12. Ancient DNA and the tropics: a rodent's tale.

    PubMed

    Gutiérrez-García, Tania A; Vázquez-Domínguez, Ella; Arroyo-Cabrales, Joaquín; Kuch, Melanie; Enk, Jacob; King, Christine; Poinar, Hendrik N

    2014-06-01

    Most genetic studies of Holocene fauna have been performed with ancient samples from dry and cold regions, in which preservation of fossils is facilitated and molecular damage is reduced. Ancient DNA work from tropical regions has been precluded owing to factors that limit DNA preservation (e.g. temperature, hydrolytic damage). We analysed ancient DNA from rodent jawbones identified as Ototylomys phyllotis, found in Holocene and Late Pleistocene stratigraphic layers from Loltún, a humid tropical cave located in the Yucatan peninsula. We extracted DNA and amplified six short overlapping fragments of the cytochrome b gene, totalling 666 bp, which represents an unprecedented success considering tropical ancient DNA samples. We performed genetic, phylogenetic and divergence time analyses, combining sequences from ancient and modern O. phyllotis, in order to assess the ancestry of the Loltún samples. Results show that all ancient samples fall into a unique clade that diverged prior to the divergence of the modern O. phyllotis, supporting it as a distinct Pleistocene form of the Ototylomys genus. Hence, this rodent's tale suggests that the sister group to modern O. phyllotis arose during the Miocene-Pliocene, diversified during the Pleistocene and went extinct in the Holocene.

  13. Advances in Rodent Research Missions on the International Space Station

    NASA Technical Reports Server (NTRS)

    Choi, S. Y.; Ronca, A.; Leveson-Gower, D.; Gong, C.; Stube, K.; Pletcher, D.; Wigley, C.; Beegle, J.; Globus, R. K.

    2016-01-01

    A research platform for rodent experiment on the ISS is a valuable tool for advancing biomedical research in space. Capabilities offered by the Rodent Research project developed at NASA Ames Research Center can support experiments of much longer duration on the ISS than previous experiments performed on the Space Shuttle. NASAs Rodent Research (RR)-1 mission was completed successfully and achieved a number of objectives, including validation of flight hardware, on-orbit operations, and science capabilities as well as support of a CASIS-sponsored experiment (Novartis) on muscle atrophy. Twenty C57BL6J adult female mice were launched on the Space-X (SpX) 4 Dragon vehicle, and thrived for up to 37 days in microgravity. Daily health checks of the mice were performed during the mission via downlinked video; all flight animals were healthy and displayed normal behavior, and higher levels of physical activity compared to ground controls. Behavioral analysis demonstrated that Flight and Ground Control mice exhibited the same range of behaviors, including eating, drinking, exploratory behavior, self- and allo-grooming, and social interactions indicative of healthy animals. The animals were euthanized on-orbit and select tissues were collected from some of the mice on orbit to assess the long-term sample storage capabilities of the ISS. In general, the data obtained from the flight mice were comparable to those from the three groups of control mice (baseline, vivarium and ground controls, which were housed in flight hardware), showing that the ISS has adequate capability to support long-duration rodent experiments. The team recovered 35 tissues from 40 RR-1 frozen carcasses, yielding 3300 aliquots of tissues to distribute to the scientific community in the U.S., including NASAs GeneLab project and scientists via Space Biology's Biospecimen Sharing Program Ames Life Science Data Archive. Tissues also were distributed to Russian research colleagues at the Institute for

  14. [Monitoring populations of rodent reservoirs of zoonotic diseases. Projects, aims and results].

    PubMed

    Jacob, J; Ulrich, R G; Freise, J; Schmolz, E

    2014-05-01

    Rodents can harbor and transmit pathogens that can cause severe disease in humans, companion animals and livestock. Such zoonotic pathogens comprise more than two thirds of the currently known human pathogens. The epidemiology of some zoonotic pathogens, such as hantaviruses, can be linked to the population dynamics of the rodent host. In this case, during an outbreak of the rodent host population many human infections may occur. In other rodent-borne zoonotic diseases such phenomena are not known and in many cases the rodent host specificity of a given pathogen is unclear. The monitoring of relevant rodent populations and of the rodent-borne zoonotic pathogens is essential to (1) understand the distribution and epidemiology of pathogens and (2) develop forecasting tools to predict outbreaks of zoonoses. Presently, there are no systematic long-term monitoring programs in place for zoonoses in Germany. Rodent monitoring activities are largely restricted to the plant protection sector, such as for the common vole (Microtus arvalis) and forest-damaging rodents. However, during the last 10-15 years a number of specific research projects have been initiated and run for a few years and Norway rat (Rattus norvegicus) monitoring has been implemented in Hamburg and Lower Saxony. Based on close cooperation of federal and state authorities and research institutions these efforts could be utilized to gain information about the distribution and importance of rodent-borne zoonoses. Nevertheless, for the integration of rodent population dynamics and zoonotic disease patterns and especially for developing predictive models, long-term monitoring is urgently required. To establish a systematic long-term monitoring program, existing networks and cooperation need to be used, additional collaborators (e.g., pest control operators) should be included and synergetic effects of different scientific fields should be utilized.

  15. The influence of the cage environment on rodent physiology and behavior: Implications for reproducibility of pre-clinical rodent research.

    PubMed

    Toth, Linda A

    2015-08-01

    The reproducibility of pre-clinical research is an important concern that is now being voiced by constituencies that include the National Institutes of Health, the pharmaceutical industry, Congress, the public and the scientific community. An important facet of performing and publishing well-controlled reproducible pre-clinical research is to stabilize and more completely define the environment of the animal subjects. Scientists who use rodents in research generally recognize the importance of maintaining a stable animal environment. However, despite a theoretical and general awareness of these issues, many may lack a true appreciation of how significantly even seemingly minor variations in the environment can affect research outcomes. The purpose of this article is to help investigators gain a more comprehensive and substantiated understanding of the potentially significant impact of even seemingly minor environmental changes on the animals and the data. An important caveat to this article is that the examples presented were selected from a very large literature, admittedly in order to illustrate certain points. The goal of this article is not to provide an overview of the entire literature on how the environment affects rodents but rather to make preclinical scientists more aware of how these factors can potentially influence the experimental data and contribute to poor reproducibility of research.

  16. DEVELOPING A PREDICTIVE SIMULATION MODEL FOR ANTIANDROGEN IMPACTS ON RODENT PROSTATE

    EPA Science Inventory

    Developing a predictive simulation model for antiandrogen impacts on rodent prostate
    HA Barton1, RW Setzer1, LK Potter1,2
    1US EPA, ORD, NHEERL, ETD, PKB, Research Triangle Park, NC and 2Curriculum in Toxicology, UNC, Chapel Hill, NC

    Alterations in rodent prostate wei...

  17. Patawa Virus, a New Arenavirus Hosted by Forest Rodents in French Guiana.

    PubMed

    Lavergne, Anne; de Thoisy, Benoit; Donato, Damien; Guidez, Amandine; Matheus, Séverine; Catzeflis, François; Lacoste, Vincent

    2015-06-01

    Molecular screening of rodents from French Guiana has detected a new arenavirus, named "Patawa," in two Oecomys species (Muridae, Sigmodontinae). Further investigations are needed to better understand the circulation of this virus in rodent and human populations and its public health impact.

  18. Molecular evolution of the nuclear von Willebrand factor gene in mammals and the phylogeny of rodents.

    PubMed

    Huchon, D; Catzeflis, F M; Douzery, E J

    1999-05-01

    Nucleotide sequences of exon 28 of the von Willebrand Factor (vWF) were analyzed for a representative sampling of rodent families and eutherian orders, with one marsupial sequence as outgroup. The aim of this study was to test if inclusion of an increased taxonomic diversity in molecular analyses would shed light on three uncertainties concerning rodent phylogeny: (1) relationships between rodent families, (2) Rodentia monophyly, and (3) the sister group relationship of rodents and lagomorphs. The results did not give evidence of any particular rodent pattern of molecular evolution relative to a general eutherian pattern. Base compositions and rates of evolution of vWF sequences of rodents were in the range of placental variation. The 10 rodent families studied here cluster in five clades: Hystricognathi, Sciuridae and Aplodontidae (Sciuroidea), Muridae, Dipodidae, and Gliridae. Among hystricognaths, the following conclusions are drawn: a single colonization event in South America by Caviomorpha, a paraphyly of Old World and New World porcupines, and an African origin for Old World porcupines. Despite a broader taxonomic sampling diversity, we did not obtain a robust answer to the question of Rodentia monophyly, but in the absence of any other alternative, we cannot reject the hypothesis of a single origin of rodents. Moreover, the phylogenetic position of Lagomorpha remains totally unsettled.

  19. Effectiveness of rodent control and monitoring techniques for a montane rainforest

    USGS Publications Warehouse

    Nelson, Jay T.; Woodworth, Bethany L.; Fancy, Steven G.; Lindsey, Gerald D.; Tweed, Eric J.

    2002-01-01

    Introduced black (Rattus rattus) and Polynesian (R. exulans) rats are damaging to native birds, insects, and plants in island ecosystems. We controlled rodent populations in a montane rainforest on the island of Hawaii to determine feasibility, cost, and effectiveness of ground-based rodent control in a rugged, remote rainforest habitat. Treatment was conducted 1996-99, from January to April each year, using rodenticide bait stations and snap-traps. We monitored rodent numbers in 48-ha treatment and reference areas before, during, and after control. As indexed by presence of rat sign in tracking tunnels or census blocks, rodent control reduced rodent abundance 58-90% each year 1 month after treatment began. There was an influx of rats into the treatment area, as shown by higher than expected numbers of rats snap-trapped on the treatment perimeter. Rodent numbers recovered to approximate pretreatment levels by the beginning of the following treatment year. Coast of equipment and supplies for rodent control for the first year was about \\$7,000 for a 1-km2 grid. After the first year, cost decreased to about \\$2,000 for 1 km2 per year. Rodent control applied continuously for 4 months each year during the breeding season may be effective in protecting nesting forest birds, but will not provide protection to plants and invertebrates vulnerable to predation throughout the year, and it is not likely to protect avian food resources.

  20. Estimation of Wildlife Hazard Levels Using Interspecies Correlation Models and Standard Laboratory Rodent Toxicity Data

    EPA Science Inventory

    Toxicity data from laboratory rodents are widely available and frequently used in human health assessments as an animal model. We explore the possibility of using single rodent acute toxicity values to predict chemical toxicity to a diversity of wildlife species and to estimate ...

  1. Teasing apart the effects of seed size and energy content on rodent scatter-hoarding behavior.

    PubMed

    Wang, Bo; Yang, Xiaolan

    2014-01-01

    Scatter-hoarding rodents are known to play a crucial role in the seed dispersal of many plant species. Numerous studies have indicated that both seed size and the energy content of seeds can affect rodent foraging behavior. However, seed size is usually associated with energy content per seed, making it difficult to isolate how seed size and energy affect rodent foraging preferences. This study used 99 treatments of artificial seeds (11 seed sizes×9 levels of energy content) to tease apart the effect of seed size and energy content on rodent seed-caching behavior. Both seed traits showed significant effects, but their details depended on the stage of the rodent foraging process. Seeds with higher energy content were harvested more rapidly while seed size only had a modest effect on harvest rate. However, after harvesting, seed size showed a much stronger effect on rodent foraging behavior. Rodents' choice of which seeds to remove and cache, as well as seed dispersal distance, seemed to reflect an optimal seed size. Our findings could be adapted in future studies to gain a better understanding of scatter-hoarding rodent foraging behavior, and the co-evolutionary dynamics between plant seed production and seed dispersers.

  2. Draft Genome Sequence of the Rodent Opportunistic Pathogen Pasteurella pneumotropica ATCC 35149T.

    PubMed

    Sasaki, Hiraku; Ishikawa, Hiroki; Asano, Ryoki; Ueshiba, Hidehiro; Matsumoto, Tetsuya; Boot, Ron; Kawamoto, Eiichi

    2014-08-07

    Pasteurella pneumotropica is an opportunistic pathogen in rodents that is commonly isolated from upper respiratory tracts in laboratory rodents. Here, we report the draft genome sequence of the P. pneumotropica type strain ATCC 35149, which was first isolated and characterized as biotype Jawetz.

  3. Translating Research from Animal Models: Does It Matter that Our Rodents are So Cold?

    EPA Science Inventory

    Does it matter that preclinical rodent models are routinely housed below their thermoneutral zone and are thereby cold-stressed? We compile evidence showing that rodents housed below their thermoneutral zone are cold-stressed, hypermetalbolic, hypertensive, sleep-deprived, obesi...

  4. Anti-erosion stone bunds influence rodent dynamics and crop damage in Ethiopian highlands

    NASA Astrophysics Data System (ADS)

    Meheretu, Yonas; Welegerima, Kiros; Teferi, Mekonen; Yirga, Gidey; Haile, Mitiku; Sluydts, Vincent; Bauer, Hans; Nyssen, Jan; Deckers, Jozef; Leirs, Herwig

    2014-05-01

    In areas of subsistence agriculture, a variety of soil conservation methods have been implemented in the last few decades to improve crop yields, however these can have unintended consequences such as providing habitat for rodent pests. We studied rodent population dynamics and estimated crop damage in high and low stone bund density fields for four cropping seasons in Tigray highlands, northern Ethiopia. Stone bunds are physical structures for soil and water conservation, and potentially habitat for rodents. We used a general model to relate the proportion of crop damage to rodent abundance, stone bund density and crop stages. We found a positive correlation between rodent abundance and crop damage, and significant variation in rodent abundance and crop damage between high and low stone bund density fields. Furthermore, crop damage also varied significantly between crop stages. We concluded that Mastomys awashensis and Arvicanthis dembeensis were the two most important crop pests in the highlands causing significant damage. Fields with high stone bund density (~10 m average distance apart) harbor more rodents and endure a significantly higher proportion of crop damage compared to fields with lower stone bund density (~15 m average distance apart). The fact that rodent abundances peaked during the reproductive stage of the crop and around harvest implies the need for management intervention before these crop stages are attained.

  5. Gait analysis methods for rodent models of arthritic disorders: reviews and recommendations.

    PubMed

    Lakes, E H; Allen, K D

    2016-11-01

    Gait analysis is a useful tool to understand behavioral changes in preclinical arthritis models. While observational scoring and spatiotemporal gait parameters are the most widely performed gait analyses in rodents, commercially available systems can now provide quantitative assessments of spatiotemporal patterns. However, inconsistencies remain between testing platforms, and laboratories often select different gait pattern descriptors to report in the literature. Rodent gait can also be described through kinetic and kinematic analyses, but systems to analyze rodent kinetics and kinematics are typically custom made and often require sensitive, custom equipment. While the use of rodent gait analysis rapidly expands, it is important to remember that, while rodent gait analysis is a relatively modern behavioral assay, the study of quadrupedal gait is not new. Nearly all gait parameters are correlated, and a collection of gait parameters is needed to understand a compensatory gait pattern used by the animal. As such, a change in a single gait parameter is unlikely to tell the full biomechanical story; and to effectively use gait analysis, one must consider how multiple different parameters contribute to an altered gait pattern. The goal of this article is to review rodent gait analysis techniques and provide recommendations on how to use these technologies in rodent arthritis models, including discussions on the strengths and limitations of observational scoring, spatiotemporal, kinetic, and kinematic measures. Recognizing rodent gait analysis is an evolving tool, we also provide technical recommendations we hope will improve the utility of these analyses in the future.

  6. Molecular Survey of Zoonotic Agents in Rodents and Other Small Mammals in Croatia.

    PubMed

    Tadin, Ante; Tokarz, Rafal; Markotić, Alemka; Margaletić, Josip; Turk, Nenad; Habuš, Josipa; Svoboda, Petra; Vucelja, Marko; Desai, Aaloki; Jain, Komal; Lipkin, W Ian

    2016-02-01

    Croatia is a focus for many rodent-borne zoonosis. Here, we report a survey of 242 rodents and small mammals, including 43 Myodes glareolus, 131 Apodemus flavicollis, 53 Apodemus agrarius, three Apodemus sylvaticus, six Sorex araneus, four Microtus arvalis, one Microtus agrestis, and one Muscardinus avellanarius, collected at eight sites in Croatia over an 8-year period. Multiplex MassTag polymerase chain reaction (PCR) was used for detection of Borrelia, Rickettsia, Bartonella, Babesia, Ehrlichia, Anaplasma, Francisella tularensis, and Coxiella burnetii. Individual PCR assays were used for detection of Leptospira, lymphocytic choriomeningitis virus, orthopoxviruses, flaviviruses, hantaviruses, and Toxoplasma gondii. Of the rodents, 52 (21.5%) were infected with Leptospira, 9 (3.7%) with Borrelia miyamotoi, 5 (2%) with Borrelia afzelii, 29 (12.0%) with Bartonella, 8 (3.3%) with Babesia microti, 2 (0.8%) with Ehrlichia, 4 (1.7%) with Anaplasma, 2 (0.8%) with F. tularensis, 43 (17.8%) with hantaviruses, and 1 (0.4%) with an orthopoxvirus. Other agents were not detected. Multiple infections were found in 32 rodents (13.2%): dual infections in 26 rodents (10.7%), triple infections in four rodents (2.9%), and quadruple infections in two rodents (0.8%). Our findings indicate that rodents in Croatia harbor a wide range of bacteria and viruses that are pathogenic to humans.

  7. Molecular Survey of Zoonotic Agents in Rodents and Other Small Mammals in Croatia

    PubMed Central

    Tadin, Ante; Tokarz, Rafal; Markotić, Alemka; Margaletić, Josip; Turk, Nenad; Habuš, Josipa; Svoboda, Petra; Vucelja, Marko; Desai, Aaloki; Jain, Komal; Ian Lipkin, W.

    2016-01-01

    Croatia is a focus for many rodent-borne zoonosis. Here, we report a survey of 242 rodents and small mammals, including 43 Myodes glareolus, 131 Apodemus flavicollis, 53 Apodemus agrarius, three Apodemus sylvaticus, six Sorex araneus, four Microtus arvalis, one Microtus agrestis, and one Muscardinus avellanarius, collected at eight sites in Croatia over an 8-year period. Multiplex MassTag polymerase chain reaction (PCR) was used for detection of Borrelia, Rickettsia, Bartonella, Babesia, Ehrlichia, Anaplasma, Francisella tularensis, and Coxiella burnetii. Individual PCR assays were used for detection of Leptospira, lymphocytic choriomeningitis virus, orthopoxviruses, flaviviruses, hantaviruses, and Toxoplasma gondii. Of the rodents, 52 (21.5%) were infected with Leptospira, 9 (3.7%) with Borrelia miyamotoi, 5 (2%) with Borrelia afzelii, 29 (12.0%) with Bartonella, 8 (3.3%) with Babesia microti, 2 (0.8%) with Ehrlichia, 4 (1.7%) with Anaplasma, 2 (0.8%) with F. tularensis, 43 (17.8%) with hantaviruses, and 1 (0.4%) with an orthopoxvirus. Other agents were not detected. Multiple infections were found in 32 rodents (13.2%): dual infections in 26 rodents (10.7%), triple infections in four rodents (2.9%), and quadruple infections in two rodents (0.8%). Our findings indicate that rodents in Croatia harbor a wide range of bacteria and viruses that are pathogenic to humans. PMID:26711522

  8. Olfactory detection of caches containing wildland versus cultivated seeds by granivorous rodents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted a study to examine the ability of rodents to detect caches made with wildland (native and non-native) and cultivated seeds at three locations in western Nevada with different vegetation types and rodent community structures. We established artificial caches containing either one of two...

  9. Neurobiology of rodent self-grooming and its value for translational neuroscience.

    PubMed

    Kalueff, Allan V; Stewart, Adam Michael; Song, Cai; Berridge, Kent C; Graybiel, Ann M; Fentress, John C

    2016-01-01

    Self-grooming is a complex innate behaviour with an evolutionarily conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders--including models of autism spectrum disorder and obsessive compulsive disorder--that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action.

  10. Hantavirus antibodies in rodents and human cases with pulmonary syndrome, Rio Negro, Argentina.

    PubMed

    Larrieu, Edmundo; Cantoni, Gustavo; Herrero, Eduardo; Pérez, Alicia; Talmon, Gabriel; Vázquez, Gabriela; Arellano, Odila; Padula, Paula

    2008-01-01

    In Río Negro Province, Argentina, human cases of hantavirus pulmonary syndrome (HPS) appeared in the region of subantarctic forests. The Andes virus (ANDV) has been identified in the region both in Oligoryzomys longicaudatus rodents and in humans, with the main transmission being from rodents to humans but also showing the possibility of human to human transmission. Between 1996 and 2004, in 40 campaigns, 29.960 night-traps for capturing live rodents were set up. Blood samples were obtained from the rodents and processed using enzyme immunoassay with recombinant antigens made from ANDV. A total of 1767 rodents were captured, with a capture success of 5.9% and an antibody prevalence of 2.1%. Important differences were observed among the species captured from Andes and Steppe regions. Seropositive Oligoryzomys longicaudatus, Abrotrix olivaceus, Abrotrix xanhtothinus and Loxodontomus microtus were captured. During the 1993-2004 period, 40 HPS cases were registered.

  11. Neurobiology of rodent self-grooming and its value for translational neuroscience

    PubMed Central

    Kalueff, Allan V.; Stewart, Adam Michael; Song, Cai; Berridge, Kent C.; Graybiel, Ann M.; Fentress, John C.

    2016-01-01

    Self-grooming is a complex innate behaviour with an evolutionary conserved sequencing pattern and is one of the most frequently performed behavioural activities in rodents. In this Review, we discuss the neurobiology of rodent self-grooming, and we highlight studies of rodent models of neuropsychiatric disorders — including models of autism spectrum disorder and obsessive compulsive disorder — that have assessed self-grooming phenotypes. We suggest that rodent self-grooming may be a useful measure of repetitive behaviour in such models, and therefore of value to translational psychiatry. Assessment of rodent self-grooming may also be useful for understanding the neural circuits that are involved in complex sequential patterns of action. PMID:26675822

  12. Occurrence of pathogens in wild rodents caught on Swedish pig and chicken farms.

    PubMed

    Backhans, A; Jacobson, M; Hansson, I; Lebbad, M; Lambertz, S Thisted; Gammelgård, E; Saager, M; Akande, O; Fellström, C

    2013-09-01

    A total of 207 wild rodents were caught on nine pig farms, five chicken farms and five non-farm locations in Sweden and surveyed for a selection of bacteria, parasites and viruses. Lawsonia intracellularia and pathogenic Yersinia enterocolitica were only detected in rodents on pig farms (9% and 8% prevalence, respectively) which indicate that these agents are more likely to be transmitted to rodents from pigs or the environment on infected farms. Brachyspira hyodysenteriae (1%), Brachyspira intermedia (2%), Campylobacter jejuni (4%), Campylobacter upsaliensis (2%), leptospires (7%) and encephalomyocarditis virus (9%) were also detected from rodents not in contact with farm animals. Giardia and Cryptosporidium spp. were common, although no zoonotic types were verified, and Salmonella enterica was isolated from 1/11 mice on one farm but not detected by PCR from any of the rodents. Trichinella spp. and Toxoplasma gondii were not detected.

  13. Genetic evidence of hantavirus infections in wild rodents from northwestern Colombia.

    PubMed

    Londoño, Andres F; Díaz, Francisco J; Agudelo-Flórez, Piedad; Levis, Silvana; Rodas, Juan D

    2011-06-01

    This report builds on recent serological evidence for the presence of hantavirus in northern Colombia by providing sequence-specific and phylogenetic data of hantavirus infections in wild rodents. From August 2007 to August 2008, 354 rodent specimens representing four families were collected in the northwestern Antioquia region of Colombia. Antibodies reactive to Sin Nombre virus and Maciel virus antigens by IgG enzyme-linked immunosorbent assay were found in 15 of 109 (14%) Cherries cane rats (Zygodontomys cherriei), the only sigmodontinae rodents captured. Lung tissue samples from 11 of the 15 seropositive rodents were RT-polymerase chain reaction positive for hantavirus RNA, using primers for the S and M genome segments. Eight of these amplicons were sequenced and phylogenetic analyses indicated RNA of a hantavirus closely related to Calabazo virus, previously found in Panama. This is the first report of the genetic characterization of a hantavirus in rodents in Colombia.

  14. Effects of fat and protein levels on foraging preferences of tannin in scatter-hoarding rodents.

    PubMed

    Wang, Bo; Chen, Jin

    2012-01-01

    Both as consumers and dispersers of seeds, scatter-hoarding rodents often play an important role in the reproductive ecology of many plant species. However, the seeds of many plant species contain tannins, which are a diverse group of water-soluble phenolic compounds that have a high affinity for proteins. The amount of tannins in seeds is expected to affect rodent foraging preferences because of their major impact on rodent physiology and survival. However, variable results have been obtained in studies that evaluated the effects of tannin on rodent foraging behavior. Hence, in this study, we aimed to explain these inconsistent results and proposed that a combination of seed traits might be important in rodent foraging behavior, because it is difficult to distinguish between the effects of individual traits on rodent foraging behavior and the interactions among them. By using a novel artificial seed system, we manipulated seed tannin and fat/protein levels to examine directly the univariate effects of each component on the seed preferences of free-ranging forest rats (Apodemus latronum and Apodemus chevrieri) during the behavioral process of scatter hoarding. Our results showed that both tannin and fat/protein had significant effects on rodent foraging behavior. Although only a few interactive effects of tannin and fat/protein were recorded, higher concentrations of both fat and protein could attenuate the exclusion of seeds with higher tannin concentrations by rodents, thus influencing seed fate. Furthermore, aside from the concentrations of tannin, fat, and protein, numerous other traits of plant seeds may also influence rodent foraging behavior. We suggest that by clarifying rodent foraging preferences, a better understanding of the evolution of plant seed traits may be obtained because of their strong potential for selective pressure.

  15. Rodent Species Distribution and Hantavirus Seroprevalence in Residential and Forested areas of Sarawak, Malaysia.

    PubMed

    Hamdan, Nur Elfieyra Syazana; Ng, Yee Ling; Lee, Wei Bin; Tan, Cheng Siang; Khan, Faisal Ali Anwarali; Chong, Yee Ling

    2017-01-01

    Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential (n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) (p < 0.001 of Zar-t test based on the Shannon index). Rattus rattus and Sundamys muelleri were present at high frequencies in both localities. An enzyme-linked immunosorbent assay (ELISA) showed that hantavirus-targeting antibodies were absent from 53 tested serum samples. This is the first report of hantavirus seroprevalence surveillance in rodent populations in Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia.

  16. Ground-based rodent control in a remote Hawaiian rainforest on Maui

    USGS Publications Warehouse

    Malcolm, T.R.; Swinnerton, K.J.; Groombridge, J.J.; Sparklin, B.D.; Brosius, C.N.; Vetter, J.P.; Foster, J.T.

    2008-01-01

    Effective control of introduced mammalian predators is essential to the recovery of native bird species in Hawai'i. Between August 1996 and December 2004, introduced rodents were controlled within three home ranges of the Po'ouli Melamprosops phaeosoma, a critically endangered Hawaiian honeycreeper. Rats were controlled using a combination of ground-based rodenticide (0.005% diphacinone) application and snap traps. Beginning in August 2001, we monitored the effectiveness of these rodent control efforts. Relative abundances of Black Rats Rattus rattus and Polynesian Rats R. exulans were measured in each of five snap-trapping grids seven times over a 35-month period. Rat populations decreased inside of the rodent control areas, but control effectiveness differed between rat species. During the first year of monitoring, target control levels for R. rattus were consistently achieved in only one of the rodent control areas. Control techniques were refined in areas failing to meet targets. Subsequently, we achieved target control levels for R. rattus more consistently in all three rodent control areas. However, relative abundances of R. exulans did not differ between rodent control and reference areas, indicating that our rodent control techniques were insufficient to reduce population levels of this species. These findings signify a need for further improvement of rodent control methods in Hawai'i, especially for Polynesian Rats, and demonstrate the critical importance of periodic monitoring of the response of rodent populations to management. In the future, managers may need to design rodent control operations targeting R. rattus and R. exulans independently to achieve best results.

  17. Rodent and flea abundance fail to predict a plague epizootic in black-tailed prairie dogs.

    PubMed

    Brinkerhoff, Robert Jory; Collinge, Sharon K; Ray, Chris; Gage, Ken L

    2010-01-01

    Small rodents are purported to be enzootic hosts of Yersinia pestis and may serve as sources of infection to prairie dogs or other epizootic hosts by direct or flea-mediated transmission. Recent research has shown that small rodent species composition and small rodent flea assemblages are influenced by the presence of prairie dogs, with higher relative abundance of both small rodents and fleas at prairie dog colony sites compared to grasslands without prairie dogs. However, it is unclear if increased rodent or flea abundance predisposes prairie dogs to infection with Y. pestis. We tracked rodent and flea occurrence for 3 years at a number of prairie dog colony sites in Boulder County, Colorado, before, during, and after a local plague epizootic to see if high rodent or flea abundance was associated with plague-affected colonies when compared to colonies that escaped infection. We found no difference in preepizootic rodent abundance or flea prevalence or abundance between plague-positive and plague-negative colonies. Further, we saw no significant before-plague/after-plague change in these metrics at either plague-positive or plague-negative sites. We did, however, find that small rodent species assemblages changed in the year following prairie dog die-offs at plague-affected colonies when compared to unaffected colonies. In light of previous research from this system that has shown that landscape features and proximity to recently plagued colonies are significant predictors of plague occurrence in prairie dogs, we suggest that landscape context is more important to local plague occurrence than are characteristics of rodent or flea species assemblages.

  18. Characterization of novel Brucella strains originating from wild native rodent species in North Queensland, Australia.

    PubMed

    Tiller, Rebekah V; Gee, Jay E; Frace, Michael A; Taylor, Trevor K; Setubal, Joao C; Hoffmaster, Alex R; De, Barun K

    2010-09-01

    We report on the characterization of a group of seven novel Brucella strains isolated in 1964 from three native rodent species in North Queensland, Australia, during a survey of wild animals. The strains were initially reported to be Brucella suis biovar 3 on the basis of microbiological test results. Our results indicated that the rodent strains had microbiological traits distinct from those of B. suis biovar 3 and all other Brucella spp. To reinvestigate these rodent strains, we sequenced the 16S rRNA, recA, and rpoB genes and nine housekeeping genes and also performed multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA). The rodent strains have a unique 16S rRNA gene sequence compared to the sequences of the classical Brucella spp. Sequence analysis of the recA, rpoB, and nine housekeeping genes reveals that the rodent strains are genetically identical to each other at these loci and divergent from any of the currently described Brucella sequence types. However, all seven of the rodent strains do exhibit distinctive allelic MLVA profiles, although none demonstrated an amplicon for VNTR 07, whereas the other Brucella spp. did. Phylogenetic analysis of the MLVA data reveals that the rodent strains form a distinct clade separate from the classical Brucella spp. Furthermore, whole-genome sequence comparison using the maximal unique exact matches index (MUMi) demonstrated a high degree of relatedness of one of the seven rodent Brucella strains (strain NF 2653) to another Australian rodent Brucella strain (strain 83-13). Our findings strongly suggest that this group of Brucella strains isolated from wild Australian rodents defines a new species in the Brucella genus.

  19. Rodent Species Distribution and Hantavirus Seroprevalence in Residential and Forested areas of Sarawak, Malaysia

    PubMed Central

    Hamdan, Nur Elfieyra Syazana; Ng, Yee Ling; Lee, Wei Bin; Tan, Cheng Siang; Khan, Faisal Ali Anwarali; Chong, Yee Ling

    2017-01-01

    Rodents belong to the order Rodentia, which consists of three families in Borneo (i.e., Muridae, Sciuridae and Hystricidae). These include rats, mice, squirrels, and porcupines. They are widespread throughout the world and considered pests that harm humans and livestock. Some rodent species are natural reservoirs of hantaviruses (Family: Bunyaviridae) that can cause zoonotic diseases in humans. Although hantavirus seropositive human sera were reported in Peninsular Malaysia in the early 1980s, information on their infection in rodent species in Malaysia is still lacking. The rodent populations in residential and forested areas in Sarawak were sampled. A total of 108 individuals from 15 species of rodents were collected in residential (n = 44) and forested ( n = 64) areas. The species diversity of rodents in forested areas was significantly higher (H = 2.2342) compared to rodents in residential areas (H = 0.64715) (p < 0.001 of Zar-t test based on the Shannon index). Rattus rattus and Sundamys muelleri were present at high frequencies in both localities. An enzyme-linked immunosorbent assay (ELISA) showed that hantavirus-targeting antibodies were absent from 53 tested serum samples. This is the first report of hantavirus seroprevalence surveillance in rodent populations in Sarawak, East Malaysia. The results suggested that hantavirus was not circulating in the studied rodent populations in Sarawak, or it was otherwise at a low prevalence that is below the detection threshold. It is important to remain vigilant because of the zoonotic potential of this virus and its severe disease outcome. Further studies, such as molecular detection of viral genetic materials, are needed to fully assess the risk of hantavirus infection in rodents and humans in this region of Malaysia. PMID:28228923

  20. Next-Generation Sequencing for Rodent Barcoding: Species Identification from Fresh, Degraded and Environmental Samples

    PubMed Central

    Galan, Maxime; Pagès, Marie; Cosson, Jean-François

    2012-01-01

    Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification

  1. Next-generation sequencing for rodent barcoding: species identification from fresh, degraded and environmental samples.

    PubMed

    Galan, Maxime; Pagès, Marie; Cosson, Jean-François

    2012-01-01

    Rodentia is the most diverse order among mammals, with more than 2,000 species currently described. Most of the time, species assignation is so difficult based on morphological data solely that identifying rodents at the specific level corresponds to a real challenge. In this study, we compared the applicability of 100 bp mini-barcodes from cytochrome b and cytochrome c oxidase 1 genes to enable rodent species identification. Based on GenBank sequence datasets of 115 rodent species, a 136 bp fragment of cytochrome b was selected as the most discriminatory mini-barcode, and rodent universal primers surrounding this fragment were designed. The efficacy of this new molecular tool was assessed on 946 samples including rodent tissues, feces, museum samples and feces/pellets from predators known to ingest rodents. Utilizing next-generation sequencing technologies able to sequence mixes of DNA, 1,140 amplicons were tagged, multiplexed and sequenced together in one single 454 GS-FLX run. Our method was initially validated on a reference sample set including 265 clearly identified rodent tissues, corresponding to 103 different species. Following validation, 85.6% of 555 rodent samples from Europe, Asia and Africa whose species identity was unknown were able to be identified using the BLASTN program and GenBank reference sequences. In addition, our method proved effective even on degraded rodent DNA samples: 91.8% and 75.9% of samples from feces and museum specimens respectively were correctly identified. Finally, we succeeded in determining the diet of 66.7% of the investigated carnivores from their feces and 81.8% of owls from their pellets. Non-rodent species were also identified, suggesting that our method is sensitive enough to investigate complete predator diets. This study demonstrates how this molecular identification method combined with high-throughput sequencing can open new realms of possibilities in achieving fast, accurate and inexpensive species identification.

  2. Rodent Abundance Dynamics and Leptospirosis Carriage in an Area of Hyper-Endemicity in New Caledonia

    PubMed Central

    Perez, Julie; Brescia, Fabrice; Becam, Jérôme; Mauron, Carine; Goarant, Cyrille

    2011-01-01

    Background Widespread but particularly incident in the tropics, leptospirosis is transmitted to humans directly or indirectly by virtually any Mammal species. However, rodents are recognized as the most important reservoir. In endemic regions, seasonal outbreaks are observed during hot rainy periods. In such regions, hot spots can be evidenced, where leptospirosis is “hyper-endemic”, its incidence reaching 500 annual cases per 100,000. A better knowledge of how rodent populations and their Leptospira prevalence respond to seasonal and meteorological fluctuations might help implement relevant control measures. Methodology/Principal Findings In two tribes in New Caledonia with hyper-endemic leptospirosis, rodent abundance and Leptospira prevalence was studied twice a year, in hot and cool seasons for two consecutive years. Highly contrasted meteorological situations, particularly rainfall intensities, were noted between the two hot seasons studied. Our results show that during a hot and rainy period, both the rodent populations and their Leptospira carriage were higher. This pattern was more salient in commensal rodents than in the sylvatic rats. Conclusions/Significance The dynamics of rodents and their Leptospira carriage changed during the survey, probably under the influence of meteorology. Rodents were both more numerous and more frequently carrying (therefore disseminating) leptospires during a hot rainy period, also corresponding to a flooding period with higher risks of human exposure to waters and watered soils. The outbreaks of leptospirosis in hyper-endemic areas could arise from meteorological conditions leading to both an increased risk of exposure of humans and an increased volume of the rodent reservoir. Rodent control measures would therefore be most effective during cool and dry seasons, when rodent populations and leptospirosis incidence are low. PMID:22039557

  3. Behavioral Effects of Developmental Methylmercury Drinking Water Exposure in Rodents

    PubMed Central

    Bisen-Hersh, Emily B.; Farina, Marcelo; Barbosa, Fernando; Rocha, Joao BT; Aschner, Michael

    2013-01-01

    Early methylmercury (MeHg) exposure can have long-lasting consequences likely arising from impaired developmental processes, the outcome of which has been exposed in several longitudinal studies of affected populations. Given the large number of newborns at an increased risk of learning disabilities associated with in utero MeHg exposure, it is important to study neurobehavioral alterations using ecologically valid and physiologically relevant models. This review highlights the benefits of using the MeHg drinking water exposure paradigm and outlines behavioral outcomes arising from this procedure in rodents. Combination treatments that exacerbate or ameliorate MeHg-induced effects, and possible molecular mechanisms underlying behavioral impairment are also discussed. PMID:24210169

  4. Obesity and stroke: Can we translate from rodents to patients?

    PubMed

    Haley, Michael J; Lawrence, Catherine B

    2016-12-01

    Obesity is a risk factor for stroke and is consequently one of the most common co-morbidities found in patients. There is therefore an identified need to model co-morbidities preclinically to allow better translation from bench to bedside. In preclinical studies, both diet-induced and genetically obese rodents have worse stroke outcome, characterised by increased ischaemic damage and an altered inflammatory response. However, clinical studies have reported an 'obesity paradox' in stroke, characterised by reduced mortality and morbidity in obese patients. We discuss the potential reasons why the preclinical and clinical studies may not agree, and review the mechanisms identified in preclinical studies through which obesity may affects stroke outcome. We suggest inflammation plays a central role in this relationship, as obesity features increases in inflammatory mediators such as C-reactive protein and interleukin-6, and chronic inflammation has been linked to worse stroke risk and outcome.

  5. Roles of dental development and adaptation in rodent evolution.

    PubMed

    Rodrigues, Helder Gomes; Renaud, Sabrina; Charles, Cyril; Le Poul, Yann; Solé, Floréal; Aguilar, Jean-Pierre; Michaux, Jacques; Tafforeau, Paul; Headon, Denis; Jernvall, Jukka; Viriot, Laurent

    2013-01-01

    In paleontology, many changes affecting morphology, such as tooth shape in mammals, are interpreted as ecological adaptations that reflect important selective events. Despite continuing studies, the identification of the genetic bases and key ecological drivers of specific mammalian dental morphologies remains elusive. Here we focus on the genetic and functional bases of stephanodonty, a pattern characterized by longitudinal crests on molars that arose in parallel during the diversification of murine rodents. We find that overexpression of Eda or Edar is sufficient to produce the longitudinal crests defining stephanodonty in transgenic laboratory mice. Whereas our dental microwear analyses show that stephanodonty likely represents an adaptation to highly fibrous diet, the initial and parallel appearance of stephanodonty may have been facilitated by developmental processes, without being necessarily under positive selection. This study demonstrates how combining development and function can help to evaluate adaptive scenarios in the evolution of new morphologies.

  6. Melanocortin control of energy balance: evidence from rodent models.

    PubMed

    De Jonghe, Bart C; Hayes, Matthew R; Bence, Kendra K

    2011-08-01

    Regulation of energy balance is extremely complex, and involves multiple systems of hormones, neurotransmitters, receptors, and intracellular signals. As data have accumulated over the last two decades, the CNS melanocortin system is now identified as a prominent integrative network of energy balance controls in the mammalian brain. Here, we will review findings from rat and mouse models, which have provided an important framework in which to study melanocortin function. Perhaps most importantly, this review attempts for the first time to summarize recent advances in our understanding of the intracellular signaling pathways thought to mediate the action of melanocortin neurons and peptides in control of longterm energy balance. Special attention will be paid to the roles of MC4R/MC3R, as well as downstream neurotransmitters within forebrain and hindbrain structures that illustrate the distributed control of melanocortin signaling in energy balance. In addition, distinctions and controversy between rodent species will be discussed.

  7. [Microbiological diagnosis of emerging arboviral and rodent borne diseases].

    PubMed

    Negredo Antón, Ana Isabel; de Ory Manchón, Fernando; Sánchez-Seco Fariñas, M Paz; Franco Narváez, Leticia; Gegúndez Cámara, M Isabel; Navarro Mari, José M; Tenorio Matanzo, Antonio

    2015-03-01

    Vector borne viruses (VBV) include viruses transmitted by arthropods, rodents and other animals. In Spain the three main autochthonous VBVs causing human diseases are: Toscana, West Nile and Lymphocytic Choriomeningitis viruses. There are also other imported viruses that are potential threats to our public health, due to the presence of competent transmission vectors (dengue and chikungunya viruses in areas infested with Aedes albopictus), or due to the potential person-to-person transmission (Lassa and other viruses causing haemorrhagic fever). The Spanish Society for Infectious Diseases and Clinical Microbiology has responded to the emergence of VBVs by publishing a special issue of Microbiological Proceedings focused on the diagnosis of those emerging vector borne viruses of major concern in our country.

  8. Prevention of chemotherapy-induced alopecia in rodent models

    PubMed Central

    Jimenez, Joaquin J.; Roberts, Stephen M.; Mejia, Jessica; Mauro, Lucia M.; Munson, John W.; Elgart, George W.; Connelly, Elizabeth Alvarez; Chen, Qingbin; Zou, Jiangying; Goldenberg, Carlos

    2008-01-01

    Alopecia (hair loss) is experienced by thousands of cancer patients every year. Substantial-to-severe alopecia is induced by anthracyclines (e.g., adriamycin), taxanes (e.g., taxol), alkylating compounds (e.g., cyclophosphamide), and the topisomerase inhibitor etoposide, agents that are widely used in the treatment of leukemias and breast, lung, ovarian, and bladder cancers. Currently, no treatment appears to be generally effective in reliably preventing this secondary effect of chemotherapy. We observed in experiments using different rodent models that localized administration of heat or subcutaneous/intradermal injection of geldanamycin or 17-(allylamino)-17-demethoxygeldanamycin induced a stress protein response in hair follicles and effectively prevented alopecia from adriamycin, cyclophosphamide, taxol, and etoposide. Model tumor therapy experiments support the presumption that such localized hair-saving treatment does not negatively affect chemotherapy efficacy. PMID:18347939

  9. Infectivities of four isolates of Taenia taeniaeformis to various rodents.

    PubMed

    Nonaka, N; Iwaki, T; Okamoto, M; Ooi, H K; Oku, Y; Ohbayashi, M; Kamiya, M

    1994-06-01

    Taenia taeniaeformis were isolated from Norway rats captured at Sapporo (SRN isolate) and Kuala Lumpur, Malaysia (KRN) and from Bedford's gray red-backed voles at Toubetsu (TCR) and Abuta (ACR). SRN, KRN and TCR isolates showed similar degree of infectivity to various rodents in which cysticerci with hooks were obtained in laboratory rats, white tuberous lesions in mice and no cysts or lesions in Mongolian gerbils and voles. Contrary to this, inoculation with ACR isolate eggs resulted in strobilocerci formation in the liver of voles, but no cysts were observed in rats, mice or gerbils. This host specificity of ACR isolate to voles suggests that it might be a new species of Taenia.

  10. Morphological evolution, ecological diversification and climate change in rodents.

    PubMed

    Renaud, Sabrina; Michaux, Jacques; Schmidt, Daniela N; Aguilar, Jean-Pierre; Mein, Pierre; Auffray, Jean-Christophe

    2005-03-22

    Among rodents, the lineage from Progonomys hispanicus to Stephanomys documents a case of increasing size and dental specialization during an approximately 9 Myr time-interval. On the contrary, some contemporaneous generalist lineages like Apodemus show a limited morphological evolution. Dental shape can be related to diet and can be used to assess the ecological changes along the lineages. Consequently, size and shape of the first upper molar were measured in order to quantify the patterns of morphological evolution along both lineages and compare them to environmental trends. Climatic changes do not have a direct influence on evolution, but they open new ecological opportunities by changing vegetation and allow the evolution of a specialist like Stephanomys. On the other hand, environmental changes are not dramatic enough to destroy the habitat of a long-term generalist like Apodemus. Hence, our results exemplify a case of an influence of climate on the evolution of specialist species, although a generalist species may persist without change.

  11. Seroepidemiologic studies of hantavirus infection among wild rodents in California.

    PubMed Central

    Jay, M.; Ascher, M. S.; Chomel, B. B.; Madon, M.; Sesline, D.; Enge, B. A.; Hjelle, B.; Ksiazek, T. G.; Rollin, P. E.; Kass, P. H.; Reilly, K.

    1997-01-01

    A total of 4,626 mammals were serologically tested for antibodies to Sin Nombre virus. All nonrodent species were antibody negative. Among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. Of 1,921 Peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. The highest antibody prevalence (71.4% of 35) was found among P. maniculatus on Santa Cruz Island, off the southern California coast. Prevalence of antibodies among deer mice trapped near sites of human cases (26.8% of 164) was significantly higher than that of mice from other sites (odds ratio = 4.5; 95% confidence interval = 1.7, 11.6). Antibody prevalence increased with rising elevation (> 1,200 meters) and correlated with a spatial cluster of hantavirus pulmonary syndrome cases in the Sierra Nevada. PMID:9204301

  12. Rodent auditory perception: Critical band limitations and plasticity.

    PubMed

    King, J; Insanally, M; Jin, M; Martins, A R O; D'amour, J A; Froemke, R C

    2015-06-18

    What do animals hear? While it remains challenging to adequately assess sensory perception in animal models, it is important to determine perceptual abilities in model systems to understand how physiological processes and plasticity relate to perception, learning, and cognition. Here we discuss hearing in rodents, reviewing previous and recent behavioral experiments querying acoustic perception in rats and mice, and examining the relation between behavioral data and electrophysiological recordings from the central auditory system. We focus on measurements of critical bands, which are psychoacoustic phenomena that seem to have a neural basis in the functional organization of the cochlea and the inferior colliculus. We then discuss how behavioral training, brain stimulation, and neuropathology impact auditory processing and perception.

  13. Amorphous intergranular phases control the properties of rodent tooth enamel

    NASA Astrophysics Data System (ADS)

    Gordon, Lyle M.; Cohen, Michael J.; MacRenaris, Keith W.; Pasteris, Jill D.; Seda, Takele; Joester, Derk

    2015-02-01

    Dental enamel, a hierarchical material composed primarily of hydroxylapatite nanowires, is susceptible to degradation by plaque biofilm-derived acids. The solubility of enamel strongly depends on the presence of Mg2+, F-, and CO32-. However, determining the distribution of these minor ions is challenging. We show—using atom probe tomography, x-ray absorption spectroscopy, and correlative techniques—that in unpigmented rodent enamel, Mg2+ is predominantly present at grain boundaries as an intergranular phase of Mg-substituted amorphous calcium phosphate (Mg-ACP). In the pigmented enamel, a mixture of ferrihydrite and amorphous iron-calcium phosphate replaces the more soluble Mg-ACP, rendering it both harder and more resistant to acid attack. These results demonstrate the presence of enduring amorphous phases with a dramatic influence on the physical and chemical properties of the mature mineralized tissue.

  14. Transmission of Guanarito and Pirital Viruses among Wild Rodents, Venezuela

    PubMed Central

    Milazzo, Mary L.; Cajimat, Maria N.B.; Duno, Gloria; Duno, Freddy; Utrera, Antonio

    2011-01-01

    Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston’s cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston’s cotton rats were infected with PIRV. The results of analyses of field and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRV-infected Alston’s cotton rats may transmit the viruses to humans. PMID:22172205

  15. Efficiency of three anti-coagulant rodenticides on commensal rodents.

    PubMed

    Mikhail, M W; Kamilia; Allam, A M; Soliman, M I

    2007-08-01

    Susceptibiliy level to bromadilone, difencoum and coumtertraly anticoagulants were studied in different species of Norway rat Rattus norvegicus and roof rat Rattus rattus trapped from El-Qualyobia Governorate in which the anticoagulant rodenticides were used to control rodents for long periods in some rural regions at Qualyobia. Complete mortality was showed for both species and sex within a standard feeding period (6 days) indicated to be susceptible to the three anticoagulant rodenticides. The bait eaten and corresponding active ingredient showed a noticeable more intake for R. rattus than R. norvegicus for the three compounds. The time to death showed highest mean values for R. rattus comparison to R. norvegicus. Difencoum recorded highest values of time to death compare with bromadilone and coumatetralyl.

  16. Fellow travellers: Working memory and mental time travel in rodents.

    PubMed

    Dere, Ekrem; Dere, Dorothea; de Souza Silva, Maria Angelica; Huston, Joseph P; Zlomuzica, Armin

    2017-03-19

    The impairment of mental time travel is a severe cognitive symptom in patients with brain lesions and a number of neuropsychiatric disorders. Whether animals are also able to mentally travel in time both forward and backward is still a matter of debate. In this regard, we have proposed a continuum of mental time travel abilities across different animal species, with humans being the species with the ability to perform most sophisticated forms of mental time travel. In this review and perspective article, we delineate a novel approach to understand the evolution, characteristics and function of human and animal mental time travel. Furthermore, we propose a novel approach to measure mental time travel in rodents in a comprehensive manner using a test battery composed of well-validated and easy applicable tests.

  17. Pathogenesis of depression: Insights from human and rodent studies.

    PubMed

    Ménard, C; Hodes, G E; Russo, S J

    2016-05-03

    Major depressive disorder (MDD) will affect one out of every five people in their lifetime and is the leading cause of disability worldwide. Nevertheless, mechanisms associated with the pathogenesis of MDD have yet to be completely understood and current treatments remain ineffective in a large subset of patients. In this review, we summarize the most recent discoveries and insights for which parallel findings have been obtained in human depressed subjects and rodent models of mood disorders in order to examine the potential etiology of depression. These mechanisms range from synaptic plasticity mechanisms to epigenetics and the immune system where there is strong evidence to support a functional role in the development of specific depression symptomology. Ultimately we conclude by discussing how novel therapeutic strategies targeting central and peripheral processes might ultimately aid in the development of effective new treatments for MDD and related stress disorders.

  18. Obesity and stroke: Can we translate from rodents to patients?

    PubMed Central

    Haley, Michael J

    2016-01-01

    Obesity is a risk factor for stroke and is consequently one of the most common co-morbidities found in patients. There is therefore an identified need to model co-morbidities preclinically to allow better translation from bench to bedside. In preclinical studies, both diet-induced and genetically obese rodents have worse stroke outcome, characterised by increased ischaemic damage and an altered inflammatory response. However, clinical studies have reported an ‘obesity paradox’ in stroke, characterised by reduced mortality and morbidity in obese patients. We discuss the potential reasons why the preclinical and clinical studies may not agree, and review the mechanisms identified in preclinical studies through which obesity may affects stroke outcome. We suggest inflammation plays a central role in this relationship, as obesity features increases in inflammatory mediators such as C-reactive protein and interleukin-6, and chronic inflammation has been linked to worse stroke risk and outcome. PMID:27655337

  19. Rodent Auditory Perception: Critical Band Limitations and Plasticity

    PubMed Central

    King, Julia; Insanally, Michele; Jin, Menghan; Martins, Ana Raquel O.; D'amour, James A.; Froemke, Robert C.

    2015-01-01

    What do animals hear? While it remains challenging to adequately assess sensory perception in animal models, it is important to determine perceptual abilities in model systems to understand how physiological processes and plasticity relate to perception, learning, and cognition. Here we discuss hearing in rodents, reviewing previous and recent behavioral experiments querying acoustic perception in rats and mice, and examining the relation between behavioral data and electrophysiological recordings from the central auditory system. We focus on measurements of critical bands, which are psychoacoustic phenomena that seem to have a neural basis in the functional organization of the cochlea and the inferior colliculus. We then discuss how behavioral training, brain stimulation, and neuropathology impact auditory processing and perception. PMID:25827498

  20. The isolation and purification of rodent pancreatic islets of Langerhans.

    PubMed

    O'Dowd, Jacqueline F

    2009-01-01

    This chapter describes the detailed protocol for the isolation and purification of islets of Langerhans from rodent pancreas using collagenase digestion. The first step of the process is to separate and isolate the insulin-producing islets of Langerhans from the rest of the pancreas. The pancreas is excised from the animal, trimmed of non-pancreatic tissues before being inflated and chopped into small pieces. The connective tissue is then broken down with a collagenase enzyme solution to selectively digest the bulk of the exocrine tissue while leaving the endocrine islets intact and separated from their surrounding non-islet tissue. Once this process is completed, the islets of Langerhans are separated from the remaining mixture by centrifugation and purified by the means of hand picking. Once isolated, the subsequent islets can be used for a number of experimental processes.

  1. Coding odor identity and odor value in awake rodents

    PubMed Central

    Nuñez-Parra, Alexia; Li, Anan; Restrepo, Diego

    2014-01-01

    In the last decade, drastic changes in the understanding of the role of the olfactory bulb and piriform cortex in odor detection have taken place through awake behaving recording in rodents. It is clear that odor responses in mitral and granule cells are strikingly different in the olfactory bulb of anesthetized vs. awake animals. In addition, sniff recording has evidenced that mitral cell responses to odors during the sniff can convey information on the odor identity and sniff phase. Moreover, we review studies that show that the mitral cell conveys not only information on odor identity but also on whether the odor is rewarded or not (odor value). Finally, we discuss how the substantial increase in awake behaving recording raises questions for future studies. PMID:24767484

  2. Identification of novel anelloviruses with broad diversity in UK rodents

    PubMed Central

    Nishiyama, Shoko; Dutia, Bernadette M.; Stewart, James P.; Meredith, Anna L.; Shaw, Darren J.; Simmonds, Peter

    2014-01-01

    Anelloviruses are a family of small circular ssDNA viruses with a vast genetic diversity. Human infections with the prototype anellovirus, torque teno virus (TTV), are ubiquitous and related viruses have been described in a number of other mammalian hosts. Despite over 15 years of investigation, there is still little known about the pathogenesis and possible disease associations of anellovirus infections, arising in part due to the lack of a robust cell culture system for viral replication or tractable small-animal model. We report the identification of diverse anelloviruses in several species of wild rodents. The viruses are highly prevalent in wood mice (Apodemus sylvaticus) and field voles (Microtus agrestis), detectable at a low frequency in bank voles (Myodes glareolus), but absent from house mice (Mus musculus). The viruses identified have a genomic organization consistent with other anelloviruses, but form two clear phylogenetic groups that are as distinct from each other as from defined genera. PMID:24744300

  3. Endrin versus 12-ketoendrin in birds and rodents

    USGS Publications Warehouse

    Stickel, W.H.; Kaiser, T.E.; Reichel, W.L.; Kenaga, E.E.

    1979-01-01

    British workers showed that in rats the endrin metabolite, 12-ketoendrin, was five times as toxic as endrin, was probably the ultimate cause of death, and was the main form of endrin in the brain at death. In cows and rabbits, however, they detected little of this metabolite. They found none in hens. We found no 12-ketoendrin in birds of four orders that had been heavily exposed to or killed by endrin. We suggest that residue work with birds need not consider this compound unless birds have been eating endrin-killed rodents. White mice had much less 12-ketoendrin than rats, but had more endrin. In tests with spiked samples, 12-ketoendrin was successfully recovered from extracts by gel permeation chromatography, but not by florisil.

  4. Rodent models in neuroscience research: is it a rat race?

    PubMed

    Ellenbroek, Bart; Youn, Jiun

    2016-10-01

    Rodents (especially Mus musculus and Rattus norvegicus) have been the most widely used models in biomedical research for many years. A notable shift has taken place over the last two decades, with mice taking a more and more prominent role in biomedical science compared to rats. This shift was primarily instigated by the availability of a much larger genetic toolbox for mice, particularly embryonic-stem-cell-based targeting technology for gene disruption. With the recent emergence of tools for altering the rat genome, notably genome-editing technologies, the technological gap between the two organisms is closing, and it is becoming more important to consider the physiological, anatomical, biochemical and pharmacological differences between rats and mice when choosing the right model system for a specific biological question. The aim of this short review and accompanying poster is to highlight some of the most important differences, and to discuss their impact on studies of human diseases, with a special focus on neuropsychiatric disorders.

  5. Evidence for a novel bursting mechanism in rodent trigeminal neurons.

    PubMed Central

    Del Negro, C A; Hsiao, C F; Chandler, S H; Garfinkel, A

    1998-01-01

    We investigated bursting behavior in rodent trigeminal neurons. The essential mechanisms operating in the biological systems were determined based on testable predictions of mathematical models. Bursting activity in trigeminal motoneurons is consistent with a traditional mechanism employing a region of negative slope resistance in the steady-state current-voltage relationship (Smith, T. G. 1975. Nature. 253:450-452). However, the bursting dynamics of trigeminal interneurons is inconsistent with the traditional mechanisms, and is far more effectively explained by a new model of bursting that exploits the unique stability properties associated with spike threshold (Baer, S. M., T. Erneux, and J. Rinzel. 1989. SIAM J. Appl. Math. 49:55-71). PMID:9649377

  6. Excitatory GABA in rodent developing neocortex in vitro.

    PubMed

    Rheims, Sylvain; Minlebaev, Marat; Ivanov, Anton; Represa, Alfonso; Khazipov, Rustem; Holmes, Gregory L; Ben-Ari, Yehezkel; Zilberter, Yuri

    2008-08-01

    GABA depolarizes immature cortical neurons. However, whether GABA excites immature neocortical neurons and drives network oscillations as in other brain structures remains controversial. Excitatory actions of GABA depend on three fundamental parameters: the resting membrane potential (Em), reversal potential of GABA (E(GABA)), and threshold of action potential generation (Vthr). We have shown recently that conventional invasive recording techniques provide an erroneous estimation of these parameters in immature neurons. In this study, we used noninvasive single N-methyl-d-aspartate and GABA channel recordings in rodent brain slices to measure both Em and E(GABA) in the same neuron. We show that GABA strongly depolarizes pyramidal neurons and interneurons in both deep and superficial layers of the immature neocortex (P2-P10). However, GABA generates action potentials in layer 5/6 (L5/6) but not L2/3 pyramidal cells, since L5/6 pyramidal cells have more depolarized resting potentials and more hyperpolarized Vthr. The excitatory GABA transiently drives oscillations generated by L5/6 pyramidal cells and interneurons during development (P5-P12). The NKCC1 co-transporter antagonist bumetanide strongly reduces [Cl(-)]i, GABA-induced depolarization, and network oscillations, confirming the importance of GABA signaling. Thus a strong GABA excitatory drive coupled with high intrinsic excitability of L5/6 pyramidal neurons and interneurons provide a powerful mechanism of synapse-driven oscillatory activity in the rodent neocortex in vitro. In the companion paper, we show that the excitatory GABA drives layer-specific seizures in the immature neocortex.

  7. Sero-Prevalence of Rodent Pathogens in India

    PubMed Central

    Manjunath, Shrruthi; Kulkarni, Prachet G.; Nagavelu, Krishnaveni; Samuel, Rosa J.; Srinivasan, Sandhya; Ramasamy, Nandhini; Hegde, Nagendra R.; Gudde, Ramachandra S.

    2015-01-01

    Health monitoring is an integral part of laboratory animal quality standards. However, current or past prevalence data as well as regulatory requirements dictate the frequency, type and the expanse of health monitoring. In an effort to understand the prevalence of rodent pathogens in India, a preliminary study was carried out by sero-epidemiology. Sera samples obtained from 26 public and private animal facilities were analyzed for the presence of antibodies against minute virus of mice (MVM), ectromelia virus (ECTV), lymphocytic choriomeningitis virus (LCMV), mouse hepatitis virus (MHV), Sendai virus (SeV), and Mycoplasma pulmonis in mice, and SeV, rat parvo virus (RPV), Kilham’s rat virus (KRV) and sialodacryoadenitis virus (SDAV) in rats, by sandwich ELISA. It was observed that MHV was the most prevalent agent followed by Mycoplasma pulmonis and MVM in mice, and SDAV followed by RPV were prevalent in rats. On the other hand, none of the samples were positive for ECTV in mice, or SeV or KRV in rats. Multiple infections were common in both mice and rats. The incidence of MHV and Mycoplasma pulmonis was higher in facilities maintained by public organizations than in vivaria of private organizations, although the difference was not statistically different. On the other hand the prevalence of rodent pathogens was significantly higher in the northern part of India than in the South. These studies form the groundwork for detailed sero-prevalence studies which should further lay the foundations for country-specific guidelines for health monitoring of laboratory animals. PMID:26158453

  8. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.

    2009-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. Because the toxicity of lunar dust is not known, NASA has tasked its toxicology laboratory to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal/intrapharyngeal instillation. This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies are in progress to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated (ground) lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The results from the instillation studies will be useful for choosing exposure concentrations for the animal inhalation study. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The experiment with the simulate will ensure that the study techniques used with actual lunar dust will be successful. The results of instillation and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  9. Adaptive Evolution in Rodent Seminal Vesicle Secretion Proteins

    PubMed Central

    Clark, Nathaniel L.; Nguyen, Eric D.; Swanson, Willie J.

    2008-01-01

    Proteins involved in reproductive fitness have evolved unusually rapidly across diverse groups of organisms. These reproductive proteins show unusually high rates of amino acid substitutions, suggesting that the proteins have been subject to positive selection. We sought to identify seminal fluid proteins experiencing adaptive evolution because such proteins are often involved in sperm competition, host immunity to pathogens, and manipulation of female reproductive physiology and behavior. We performed an evolutionary screen of the mouse prostate transcriptome for genes with elevated evolutionary rates between mouse and rat. We observed that secreted rodent prostate proteins evolve approximately twice as fast as nonsecreted proteins, remarkably similar to findings in the primate prostate and in the Drosophila male accessory gland. Our screen led us to identify and characterize a group of seminal vesicle secretion (Svs) proteins and to show that the gene Svs7 is evolving very rapidly, with many amino acid sites under positive selection. Another gene in this group, Svs5, showed evidence of branch-specific selection in the rat. We also found that Svs7 is under selection in primates and, by using three-dimensional models, demonstrated that the same regions have been under selection in both groups. Svs7 has been identified as mouse caltrin, a protein involved in sperm capacitation, the process responsible for the timing of changes in sperm activity and behavior, following ejaculation. We propose that the most likely explanation of the adaptive evolution of Svs7 that we have observed in rodents and primates stems from an important function in sperm competition. PMID:18718917

  10. Distribution of oxytocin in the brain of a eusocial rodent.

    PubMed

    Rosen, G J; de Vries, G J; Goldman, S L; Goldman, B D; Forger, N G

    2008-08-26

    Naked mole-rats are highly social rodents that live in large colonies characterized by a rigid social and reproductive hierarchy. Only one female, the queen, breeds. Most colony members are non-reproductive subordinates that work cooperatively to rear the young and maintain an underground burrow system. Little is known about the neurobiological basis of the complex sociality exhibited by this species. The neuropeptide oxytocin (Oxt) modulates social bonding and other social behaviors in many vertebrates. Here we examined the distribution of Oxt immunoreactivity in the brains of male and female naked mole-rats. As in other species, the majority of Oxt-immunoreactive (Oxt-ir) cells were found in the paraventricular and supraoptic nuclei, with additional labeled cells scattered throughout the preoptic and anterior hypothalamic areas. Oxt-ir fibers were found traveling toward and through the median eminence, as well as in the tenia tecta, septum, and nucleus of the diagonal band of Broca. A moderate network of fibers covered the bed nucleus of the stria terminalis and preoptic area, and a particularly dense fiber innervation of the nucleus accumbens and substantia innominata was observed. In the brainstem, Oxt-ir fibers were found in the periaqueductal gray, locus coeruleus, parabrachial nucleus, nucleus of the solitary tract, and nucleus ambiguus. The high levels of Oxt immunoreactivity in the nucleus accumbens and preoptic area are intriguing, given the link in other rodents between Oxt signaling in these regions and maternal behavior. Although only the queen gives birth or nurses pups in a naked mole-rat colony, most individuals actively participate in pup care.

  11. Revisiting rodent models: Octodon degus as Alzheimer's disease model?

    PubMed

    Steffen, Johannes; Krohn, Markus; Paarmann, Kristin; Schwitlick, Christina; Brüning, Thomas; Marreiros, Rita; Müller-Schiffmann, Andreas; Korth, Carsten; Braun, Katharina; Pahnke, Jens

    2016-08-26

    Alzheimer's disease primarily occurs as sporadic disease and is accompanied with vast socio-economic problems. The mandatory basic research relies on robust and reliable disease models to overcome increasing incidence and emerging social challenges. Rodent models are most efficient, versatile, and predominantly used in research. However, only highly artificial and mostly genetically modified models are available. As these 'engineered' models reproduce only isolated features, researchers demand more suitable models of sporadic neurodegenerative diseases. One very promising animal model was the South American rodent Octodon degus, which was repeatedly described as natural 'sporadic Alzheimer's disease model' with 'Alzheimer's disease-like neuropathology'. To unveil advantages over the 'artificial' mouse models, we re-evaluated the age-dependent, neurohistological changes in young and aged Octodon degus (1 to 5-years-old) bred in a wild-type colony in Germany. In our hands, extensive neuropathological analyses of young and aged animals revealed normal age-related cortical changes without obvious signs for extensive degeneration as seen in patients with dementia. Neither significant neuronal loss nor enhanced microglial activation were observed in aged animals. Silver impregnation methods, conventional, and immunohistological stains as well as biochemical fractionations revealed neither amyloid accumulation nor tangle formation. Phosphoepitope-specific antibodies against tau species displayed similar intraneuronal reactivity in both, young and aged Octodon degus.In contrast to previous results, our study suggests that Octodon degus born and bred in captivity do not inevitably develop cortical amyloidosis, tangle formation or neuronal loss as seen in Alzheimer's disease patients or transgenic disease models.

  12. Modelling cognitive affective biases in major depressive disorder using rodents

    PubMed Central

    Hales, Claire A; Stuart, Sarah A; Anderson, Michael H; Robinson, Emma S J

    2014-01-01

    Major depressive disorder (MDD) affects more than 10% of the population, although our understanding of the underlying aetiology of the disease and how antidepressant drugs act to remediate symptoms is limited. Major obstacles include the lack of availability of good animal models that replicate aspects of the phenotype and tests to assay depression-like behaviour in non-human species. To date, research in rodents has been dominated by two types of assays designed to test for depression-like behaviour: behavioural despair tests, such as the forced swim test, and measures of anhedonia, such as the sucrose preference test. These tests have shown relatively good predictive validity in terms of antidepressant efficacy, but have limited translational validity. Recent developments in clinical research have revealed that cognitive affective biases (CABs) are a key feature of MDD. Through the development of neuropsychological tests to provide objective measures of CAB in humans, we have the opportunity to use ‘reverse translation’ to develop and evaluate whether similar methods are suitable for research into MDD using animals. The first example of this approach was reported in 2004 where rodents in a putative negative affective state were shown to exhibit pessimistic choices in a judgement bias task. Subsequent work in both judgement bias tests and a novel affective bias task suggest that these types of assay may provide translational methods for studying MDD using animals. This review considers recent work in this area and the pharmacological and translational validity of these new animal models of CABs. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24467454

  13. Simultaneous FMRI and electrophysiology in the rodent brain.

    PubMed

    Pan, Wen-ju; Thompson, Garth; Magnuson, Matthew; Majeed, Waqas; Jaeger, Dieter; Keilholz, Shella

    2010-08-19

    To examine the neural basis of the blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) signal, we have developed a rodent model in which functional MRI data and in vivo intracortical recording can be performed simultaneously. The combination of MRI and electrical recording is technically challenging because the electrodes used for recording distort the MRI images and the MRI acquisition induces noise in the electrical recording. To minimize the mutual interference of the two modalities, glass microelectrodes were used rather than metal and a noise removal algorithm was implemented for the electrophysiology data. In our studies, two microelectrodes were separately implanted in bilateral primary somatosensory cortices (SI) of the rat and fixed in place. One coronal slice covering the electrode tips was selected for functional MRI. Electrode shafts and fixation positions were not included in the image slice to avoid imaging artifacts. The removed scalp was replaced with toothpaste to reduce susceptibility mismatch and prevent Gibbs ringing artifacts in the images. The artifact structure induced in the electrical recordings by the rapidly-switching magnetic fields during image acquisition was characterized by averaging all cycles of scans for each run. The noise structure during imaging was then subtracted from original recordings. The denoised time courses were then used for further analysis in combination with the fMRI data. As an example, the simultaneous acquisition was used to determine the relationship between spontaneous fMRI BOLD signals and band-limited intracortical electrical activity. Simultaneous fMRI and electrophysiological recording in the rodent will provide a platform for many exciting applications in neuroscience in addition to elucidating the relationship between the fMRI BOLD signal and neuronal activity.

  14. DNA Barcoding of Sigmodontine Rodents: Identifying Wildlife Reservoirs of Zoonoses

    PubMed Central

    Müller, Lívia; Gonçalves, Gislene L.; Cordeiro-Estrela, Pedro; Marinho, Jorge R.; Althoff, Sérgio L.; Testoni, André. F.; González, Enrique M.; Freitas, Thales R. O.

    2013-01-01

    Species identification through DNA barcoding is a tool to be added to taxonomic procedures, once it has been validated. Applying barcoding techniques in public health would aid in the identification and correct delimitation of the distribution of rodents from the subfamily Sigmodontinae. These rodents are reservoirs of etiological agents of zoonoses including arenaviruses, hantaviruses, Chagas disease and leishmaniasis. In this study we compared distance-based and probabilistic phylogenetic inference methods to evaluate the performance of cytochrome c oxidase subunit I (COI) in sigmodontine identification. A total of 130 sequences from 21 field-trapped species (13 genera), mainly from southern Brazil, were generated and analyzed, together with 58 GenBank sequences (24 species; 10 genera). Preliminary analysis revealed a 9.5% rate of misidentifications in the field, mainly of juveniles, which were reclassified after examination of external morphological characters and chromosome numbers. Distance and model-based methods of tree reconstruction retrieved similar topologies and monophyly for most species. Kernel density estimation of the distance distribution showed a clear barcoding gap with overlapping of intraspecific and interspecific densities < 1% and 21 species with mean intraspecific distance < 2%. Five species that are reservoirs of hantaviruses could be identified through DNA barcodes. Additionally, we provide information for the description of a putative new species, as well as the first COI sequence of the recently described genus Drymoreomys. The data also indicated an expansion of the distribution of Calomys tener. We emphasize that DNA barcoding should be used in combination with other taxonomic and systematic procedures in an integrative framework and based on properly identified museum collections, to improve identification procedures, especially in epidemiological surveillance and ecological assessments. PMID:24244670

  15. Does age matter? The impact of rodent age on study outcomes.

    PubMed

    Jackson, Samuel J; Andrews, Nick; Ball, Doug; Bellantuono, Ilaria; Gray, James; Hachoumi, Lamia; Holmes, Alan; Latcham, Judy; Petrie, Anja; Potter, Paul; Rice, Andrew; Ritchie, Alison; Stewart, Michelle; Strepka, Carol; Yeoman, Mark; Chapman, Kathryn

    2017-04-01

    Rodent models produce data which underpin biomedical research and non-clinical drug trials, but translation from rodents into successful clinical outcomes is often lacking. There is a growing body of evidence showing that improving experimental design is key to improving the predictive nature of rodent studies and reducing the number of animals used in research. Age, one important factor in experimental design, is often poorly reported and can be overlooked. The authors conducted a survey to assess the age used for a range of models, and the reasoning for age choice. From 297 respondents providing 611 responses, researchers reported using rodents most often in the 6-20 week age range regardless of the biology being studied. The age referred to as 'adult' by respondents varied between six and 20 weeks. Practical reasons for the choice of rodent age were frequently given, with increased cost associated with using older animals and maintenance of historical data comparability being two important limiting factors. These results highlight that choice of age is inconsistent across the research community and often not based on the development or cellular ageing of the system being studied. This could potentially result in decreased scientific validity and increased experimental variability. In some cases the use of older animals may be beneficial. Increased scientific rigour in the choice of the age of rodent may increase the translation of rodent models to humans.

  16. [Characterization of contacts of the population of Guinea with synanthropic rodents as Lassa fever virus carriers].

    PubMed

    Inapogui, A P; Konstantinov, O K; Lapshov, V N; Comara, S K

    2007-01-01

    Questionnaire surveys made in 17 villages from 3 ecological zones of Guinea have provided evidence for the population's contact with synanthropic rodents as Lassa fever virus carriers. Over 100 rodents are quarterly captured in the houses of the traditional type in the villages located in the savanna woodland. Less than 10 specimens are captured at the food warehouses. There are more than 100 rodents in the majority of houses of the traditional type in the villages located in the secondary forest. In the villages of rainy tropical forests, the capture rate is low--10 to 100 rodents. The main rodent capturers are boys and young men (aged 7 to 20 years) who are principal rodent meat eaters; although almost the whole population, particularly in rural areas, consumes this meat in varying degrees. The proportion of captured rats of the genus Mastomys (the carrier of Lassa fever virus) in the town of Kindia is 11%. In the rural area, it is much higher (as high as 94%) in the villages located in the rainy tropical forests. It is estimated that one trapper quarterly catches 0.2 (in the savanna woodland) to 6.9 (in the secondary forests) infected rats, which agrees with the data of a serological survey of Guinea's population. By and large, the majority of the Guinean population may be referred to as a group at risk for Lassa fever due to their permanent contacts with rodents.

  17. Diversity and molecular characterization of novel hemoplasmas infecting wild rodents from different Brazilian biomes.

    PubMed

    Gonçalves, Luiz Ricardo; Roque, André Luiz Rodrigues; Matos, Carlos Antonio; Fernandes, Simone de Jesus; Olmos, Isabella Delamain Fernandez; Machado, Rosangela Zacarias; André, Marcos Rogério

    2015-12-01

    Although hemoplasma infection in domestic animals has been well documented, little is known about the prevalence and genetic diversity of these bacteria in wild rodents. The present work aimed to investigate the occurrence of hemotrophic mycoplasmas in wild rodents from five Brazilian biomes, assessing the 16S rRNA phylogenetic position of hemoplasma species by molecular approach. Spleen tissues were obtained from 500 rodents, comprising 52 different rodent species trapped between 2000 and 2011. DNA samples were submitted to previously described PCR protocols for amplifying Mycoplasma spp. based on 16S rRNA, followed by sequencing and phylogenetic inferences. Among 457 rodent spleen samples showing absence of inhibitors, 100 (21.9%) were PCR positive to Mycoplasma spp. The occurrence of hemotropic mycoplasmas among all sampled rodents was demonstrated in all five biomes and ranged from 9.3% (7/75) to 26.2% (38/145). The Blastn analysis showed that amplified sequences had a percentage of identity ranging from 86 to 99% with other murine hemoplasmas. The ML phylogenetic analysis of 16S rRNA gene of 24 positive randomly selected samples showed the presence of ten distinct groups, all clustering within the Mycoplasma haemofelis. The phylogenetic assessment suggests the circulation of novel hemoplasma species in rodents from different biomes in Brazil.

  18. Association of Bartonella Species with Wild and Synanthropic Rodents in Different Brazilian Biomes.

    PubMed

    Gonçalves, Luiz Ricardo; Favacho, Alexsandra Rodrigues de Mendonça; Roque, André Luiz Rodrigues; Mendes, Natalia Serra; Fidelis Junior, Otávio Luiz; Benevenute, Jyan Lucas; Herrera, Heitor Miraglia; D'Andrea, Paulo Sérgio; de Lemos, Elba Regina Sampaio; Machado, Rosangela Zacarias; André, Marcos Rogério

    2016-12-15

    Bartonella spp. comprise an ecologically successful group of microorganisms that infect erythrocytes and have adapted to different hosts, which include a wide range of mammals, besides humans. Rodents are reservoirs of about two-thirds of Bartonella spp. described to date; and some of them have been implicated as causative agents of human diseases. In our study, we performed molecular and phylogenetic analyses of Bartonella spp. infecting wild rodents from five different Brazilian biomes. In order to characterize the genetic diversity of Bartonella spp., we performed a robust analysis based on three target genes, followed by sequencing, Bayesian inference, and maximum likelihood analysis. Bartonella spp. were detected in 25.6% (117/457) of rodent spleen samples analyzed, and this occurrence varied among different biomes. The diversity analysis of gltA sequences showed the presence of 15 different haplotypes. Analysis of the phylogenetic relationship of gltA sequences performed by Bayesian inference and maximum likelihood showed that the Bartonella species detected in rodents from Brazil was closely related to the phylogenetic group A detected in other cricetid rodents from North America, probably constituting only one species. Last, the Bartonella species genogroup identified in the present study formed a monophyletic group that included Bartonella samples from seven different rodent species distributed in three distinct biomes. In conclusion, our study showed that the occurrence of Bartonella bacteria in rodents is much more frequent and widespread than previously recognized.

  19. Flea, rodent, and plague ecology at Chuchupate Campground, Ventura County, California.

    PubMed

    Davis, Richard M; Smith, Randall T; Madon, Minoo B; Sitko-Cleugh, Erika

    2002-06-01

    Chuchupate Campground in Ventura County, California, was closed to the public for 18 years (1982 to 2000) because of uncontrolled vector fleas and persistent plague antibody titers in rodents. The primary purpose of this study was to clarify the plague ecology of Chuchupate Campground by identifying involved rodents and their vector fleas and by determining many of their ecological parameters: abundance, flea and host preferences and diversities, and flea seasonality. Rodents and fleas were identified to species, some fleas were tested for Yersinia pestis, and rodent bloods were analyzed for the presence of antibodies to Y. pestis. During this study, 20 flea species were identified from 10 rodent and one lagomorph species collected. Five species of rodents were seropositive for plague during 13 of the 17 years in which plague testing was conducted. A likely reservoir species was not determined, but evidence of plague resistance was discovered in Merriam's chipmunks (Tamias merriami) and dusky-footed woodrats (Neotoma fuscipes). The "susceptible" rodent and flea complexes at Chuchupate are the California ground squirrel (Spermophilus beecheyi) and its fleas, Oropsylla montana and Hoplopsyllus anomalus, Merriam's chipmunk and its flea, Eumolpianusfornacis, and the dusky-footed woodrat and its flea, Orchopeas sexdentatus. Host preference, diversity, and seasonality of fleas are discussed, as well as the pivotal role of woodrat houses and nests as foci for hosts, fleas, and plague.

  20. Oncogene activation in spontaneous and chemically induced rodent tumors: implications for risk analysis

    SciTech Connect

    Reynolds, S.H.; Stowers, S.J.; Patterson, R.M.; Maronpot, R.R.; Anderson, M.W.

    1988-06-01

    The validity of rodent tumor end points in assessing the potential hazards of chemical exposure to humans is a somewhat controversial but very important issue since most chemicals are classified as potentially hazardous to humans on the basis of long-term carcinogenesis studies in rodents. The ability to distinguish between genotoxic, cytotoxic, or receptor-mediated promotion effects of chemical treatment would aid in the interpretation of rodent carcinogenesis data. Activated oncogenes in spontaneously occurring and chemically induced rodent tumors were examined and compared as one approach to determine the mechanism by which chemical treatment caused an increased incidence of rodent tumors. Different patterns of activated oncogenes were found not only in spontaneous versus chemically induced mouse liver tumors but also in a variety of spontaneous rat tumors versus chemically induced rat lung tumors. In the absence of cytotoxic effects, it could be argued that the chemicals in question activated protooncogenes by a direct genotoxic mechanism. These results provided a basis for the analysis of activated oncogenes in spontaneous and chemically induced rodent tumors to provide information at a molecular level to aid in the extrapolation of rodent carcinogenesis data to human risk assessment.

  1. Does age matter? The impact of rodent age on study outcomes

    PubMed Central

    Andrews, Nick; Ball, Doug; Bellantuono, Ilaria; Gray, James; Hachoumi, Lamia; Holmes, Alan; Latcham, Judy; Petrie, Anja; Potter, Paul; Rice, Andrew; Ritchie, Alison; Stewart, Michelle; Strepka, Carol; Yeoman, Mark; Chapman, Kathryn

    2016-01-01

    Rodent models produce data which underpin biomedical research and non-clinical drug trials, but translation from rodents into successful clinical outcomes is often lacking. There is a growing body of evidence showing that improving experimental design is key to improving the predictive nature of rodent studies and reducing the number of animals used in research. Age, one important factor in experimental design, is often poorly reported and can be overlooked. The authors conducted a survey to assess the age used for a range of models, and the reasoning for age choice. From 297 respondents providing 611 responses, researchers reported using rodents most often in the 6–20 week age range regardless of the biology being studied. The age referred to as ‘adult’ by respondents varied between six and 20 weeks. Practical reasons for the choice of rodent age were frequently given, with increased cost associated with using older animals and maintenance of historical data comparability being two important limiting factors. These results highlight that choice of age is inconsistent across the research community and often not based on the development or cellular ageing of the system being studied. This could potentially result in decreased scientific validity and increased experimental variability. In some cases the use of older animals may be beneficial. Increased scientific rigour in the choice of the age of rodent may increase the translation of rodent models to humans. PMID:27307423

  2. Zoonotic and Non-zoonotic Parasites of Wild Rodents in Turkman Sahra, Northeastern Iran

    PubMed Central

    GHOLIPOURY, Monireh; REZAI, Hamid Reza; NAMROODI, Somayeh; ARAB KHAZAELI, Fatemeh

    2016-01-01

    Background: This study was conducted to collect informative data on the parasitic infection of wild rodents, emphasizing on finding parasites, which have medical importance to human. Methods: During 2012–2014, a total number of 91 wild rodents were captured from rural areas of Turkmen Sahra, Golestan Province, using handmade traps. Animals were anesthetized, surveyed for any ectoparasite and then their carcasses were carefully dissected for examination of endoparsites. Results: Four species of rodents including Mus musculus (52.75%), Rattus norvegicus (38.46%), Rhombomys opimus (4.40%) and Meriones libycus (4.40%) were captured. Parasitic infestation was detected in 38.5% of sampled rodents. Parasite infestation rates of sampled rodents was Hymenolepis diminuta = 7.7%, Cryptosporidium spp = 6.6%, Trichuris spp.= 5.5%, Cysticercus fasciolaris = 2.20%, Angiostrongylus spp.= 2.20%, Capillaria sp.= 1.09%, Rhipicephalus spp. = 8.70%, Nosopsyllus fasciatus = 1.09%, and Laelaps nuttalli = 3.29%. Among 10 genera/species of identified parasites, at least 8 of them were zoonotic with public health importance. L. nuttalli and N. fasciatus were the only two non-zoonotic detected parasites in this survey. Conclusion: Harboring a wide variety of zoonotic parasites in sampled wild rodents particularly when they live nearby villages, represents a potential risk to native inhabitants. Hence, controlling rodents’ population in residential regions and improving awareness of local people about the risk of disease transmission through rodents seems to be entirely necessary. PMID:28127340

  3. Domestic cats and dogs create a landscape of fear for pest rodents around rural homesteads

    PubMed Central

    Mahlaba, Themb’alilahlwa A. M.; Monadjem, Ara; McCleery, Robert; Belmain, Steven R.

    2017-01-01

    Using domestic predators such as cats to control rodent pest problems around farms and homesteads is common across the world. However, practical scientific evidence on the impact of such biological control in agricultural settings is often lacking. We tested whether the presence of domestic cats and/or dogs in rural homesteads would affect the foraging behaviour of pest rodents. We estimated giving up densities (GUDs) from established feeding patches and estimated relative rodent activity using tracking tiles at 40 homesteads across four agricultural communities. We found that the presence of cats and dogs at the same homestead significantly reduced activity and increased GUDs (i.e. increased perception of foraging cost) of pest rodent species. However, if only cats or dogs alone were present at the homestead there was no observed difference in rodent foraging activity in comparison to homesteads with no cats or dogs. Our results suggest that pest rodent activity can be discouraged through the presence of domestic predators. When different types of predator are present together they likely create a heightened landscape of fear for foraging rodents. PMID:28158266

  4. Public Health Implications of Changing Rodent Importation Patterns - United States, 1999-2013.

    PubMed

    Lankau, E W; Sinclair, J R; Schroeder, B A; Galland, G G; Marano, N

    2017-04-01

    The United States imports a large volume of live wild and domestic animal species; these animals pose a demonstrated risk for introduction of zoonotic diseases. Rodents are imported for multiple purposes, including scientific research, zoo exhibits and the pet trade. Current U.S. public health regulatory restrictions specific to rodent importation pertain only to those of African origin. To understand the impacts of these regulations and the potential public health risks of international rodent trade to the United States, we evaluated live rodent import records during 1999-2013 by shipment volume and geographic origin, source (e.g. wild-caught versus captive- or commercially bred), intended purpose and rodent taxonomy. Live rodent imports increased from 2737 animals during 1999 to 173 761 animals during 2013. Increases in both the number and size of shipments contributed to this trend. The proportion of wild-captured imports declined from 75% during 1999 to <1% during 2013. Nearly all shipments during these years were imported for commercial purposes. Imports from Europe and other countries in North America experienced notable increases in volume. Gerbils and hamsters arriving from Europe and chinchillas, guinea pigs and hamsters arriving from other countries in North America were predominant taxa underlying this trend. After 2003, African-origin imports became sporadic events under the federal permit process. These patterns suggest development of large-scale captive rodent breeding markets abroad for commercial sale in the United States. While the shift from wild-captured imports alleviates many conservation concerns and risks for novel disease emergence, such consolidated sourcing might elevate exposure risks for zoonotic diseases associated with high-density rodent breeding (e.g. lymphocytic choriomeningitis or salmonellosis). A responsive border health system must periodically re-evaluate importation regulations in conjunction with key stakeholders to ensure a

  5. Seed removal by scatter-hoarding rodents: the effects of tannin and nutrient concentration.

    PubMed

    Wang, Bo; Yang, Xiaolan

    2015-04-01

    The mutualistic interaction between scatter-hoarding rodents and seed plants have a long co-evolutionary history. Plants are believed to have evolved traits that influence the foraging behavior of rodents, thus increasing the probability of seed removal and caching, which benefits the establishment of seedlings. Tannin and nutrient content in seeds are considered among the most essential factors in this plant-animal interaction. However, most previous studies used different species of plant seeds, rendering it difficult to tease apart the relative effect of each single nutrient on rodent foraging behavior due to confounding combinations of nutrient contents across seed species. Hence, to further explore how tannin and different nutritional traits of seed affect scatter-hoarding rodent foraging preferences, we manipulated tannin, fat, protein and starch content levels, and also seed size levels by using an artificial seed system. Our results showed that both tannin and various nutrients significantly affected rodent foraging preferences, but were also strongly affected by seed size. In general, rodents preferred to remove seeds with less tannin. Fat addition could counteract the negative effect of tannin on seed removal by rodents, while the effect of protein addition was weaker. Starch by itself had no effect, but it interacted with tannin in a complex way. Our findings shed light on the effects of tannin and nutrient content on seed removal by scatter-hoarding rodents. We therefore, believe that these and perhaps other seed traits should interactively influence this important plant-rodent interaction. However, how selection operates on seed traits to counterbalance these competing interests/factors merits further study.

  6. Correlates of Recent Declines of Rodents in Northern and Southern Australia: Habitat Structure Is Critical.

    PubMed

    Lawes, Michael J; Fisher, Diana O; Johnson, Chris N; Blomberg, Simon P; Frank, Anke S K; Fritz, Susanne A; McCallum, Hamish; VanDerWal, Jeremy; Abbott, Brett N; Legge, Sarah; Letnic, Mike; Thomas, Colette R; Thurgate, Nikki; Fisher, Alaric; Gordon, Iain J; Kutt, Alex

    2015-01-01

    Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia) on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent) and red foxes (in the south). Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall), our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south.

  7. Landform and surface attributes for prediction of rodent burrows in the Western Usambara Mountains, Tanzania.

    PubMed

    Meliyo, Joel L; Massawe, Boniface H J; Msanya, Balthazar M; Kimaro, Didas N; Hieronimo, Proches; Mulungu, Loth S; Kihupi, Nganga I; Deckers, Jozef A; Gulinck, Hubert; Leirs, Herwig

    2014-07-01

    Previous studies suggest that rodent burrows, a proxy for rodent population are important for predicting plague risk areas. However, studies that link landform, surface attributes and rodent burrows in the Western Usambara Mountains in Tanzania are scanty. Therefore, this study was conducted in plague endemic area of the Western Usambara Mountains in northern, Tanzania, to explore the relationship between rodent burrows, and landform and surface attributes. The study was carried out in three areas corresponding to high (Lokome), medium (Lukozi) and low.(Mwangoi) frequency of reported plague cases. Data were collected from 117, 200 and 170 observation sites for Lokome, Lukozi and Mwangoi, respectively using 100 m x 200 m quadrats. Remote sensing and field surveys were used to collect data on landform and surface attributes. Rodent burrows were surveyed and quantified by counting the number of burrows in 20m x 20m grids demarcated on the main 100m x 200m quadrats. The collected data were analysed in R software using boosted regression trees (BRT) technique. Rodent burrows were found at an elevation of above 1600m in the high and medium plague frequency landscapes. No burrows were found in the low plague frequency landscape situated below 1500m. BRT analysis shows a significant relationship between landform characteristics and rodent burrows in both high and medium plague frequency landscapes. Overall, elevation and hillshade are the most important determinants of rodent burrow distribution in the studied landscapes. It is concluded that in high altitudes, specific landform attributes (hill-shade, slope, elevation) and vegetation cover- favour rodent burrowing.

  8. Camera Trapping: A Contemporary Approach to Monitoring Invasive Rodents in High Conservation Priority Ecosystems

    PubMed Central

    Rendall, Anthony R.; Sutherland, Duncan R.; Cooke, Raylene; White, John

    2014-01-01

    Invasive rodent species have established on 80% of the world's islands causing significant damage to island environments. Insular ecosystems support proportionally more biodiversity than comparative mainland areas, highlighting them as critical for global biodiversity conservation. Few techniques currently exist to adequately detect, with high confidence, species that are trap-adverse such as the black rat, Rattus rattus, in high conservation priority areas where multiple non-target species persist. This study investigates the effectiveness of camera trapping for monitoring invasive rodents in high conservation areas, and the influence of habitat features and density of colonial-nesting seabirds on rodent relative activity levels to provide insights into their potential impacts. A total of 276 camera sites were established and left in situ for 8 days. Identified species were recorded in discrete 15 min intervals, referred to as ‘events’. In total, 19 804 events were recorded. From these, 31 species were identified comprising 25 native species and six introduced. Two introduced rodent species were detected: the black rat (90% of sites), and house mouse Mus musculus (56% of sites). Rodent activity of both black rats and house mice were positively associated with the structural density of habitats. Density of seabird burrows was not strongly associated with relative activity levels of rodents, yet rodents were still present in these areas. Camera trapping enabled a large number of rodents to be detected with confidence in site-specific absences and high resolution to quantify relative activity levels. This method enables detection of multiple species simultaneously with low impact (for both target and non-target individuals); an ideal strategy for monitoring trap-adverse invasive rodents in high conservation areas. PMID:24599307

  9. Detection of Leishmania donovani and L. tropica in Ethiopian wild rodents.

    PubMed

    Kassahun, Aysheshm; Sadlova, Jovana; Dvorak, Vit; Kostalova, Tatiana; Rohousova, Iva; Frynta, Daniel; Aghova, Tatiana; Yasur-Landau, Daniel; Lemma, Wessenseged; Hailu, Asrat; Baneth, Gad; Warburg, Alon; Volf, Petr; Votypka, Jan

    2015-05-01

    Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors, and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from northwestern Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia

  10. Correlates of Recent Declines of Rodents in Northern and Southern Australia: Habitat Structure Is Critical

    PubMed Central

    Lawes, Michael J.; Fisher, Diana O.; Johnson, Chris N.; Blomberg, Simon P.; Frank, Anke S. K.; Fritz, Susanne A.; McCallum, Hamish; VanDerWal, Jeremy; Abbott, Brett N.; Legge, Sarah; Letnic, Mike; Thomas, Colette R.; Thurgate, Nikki; Fisher, Alaric; Gordon, Iain J.; Kutt, Alex

    2015-01-01

    Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia) on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent) and red foxes (in the south). Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall), our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south. PMID:26111037

  11. Public health implications of changing rodent importation patterns— United States, 1999–2013

    PubMed Central

    Lankau, Emily W.; Sinclair, Julie R.; Schroeder, Betsy A.; Galland, G. Gale; Marano, Nina

    2015-01-01

    Summary The United States imports a large volume of live wild and domestic animal species; these animals pose a demonstrated risk for introduction of zoonotic diseases. Rodents are imported for multiple purposes, including scientific research, zoo exhibits, and the pet trade. Current U.S. public health regulatory restrictions specific to rodent importation pertain only to those of African origin. To understand the impacts of these regulations and the potential public health risks of international rodent trade to the United States, we evaluated live rodent import records during 1999 –2013 by shipment volume and geographic origin, source (e.g., wild -caught versus captive-or commercially bred), intended purpose, and rodent taxonomy. Live rodent imports increased from 2,737 animals during 1999 to 173,761 animals during 2013. Increases in both the number and size of shipments contributed to this trend. The proportion of wild-captured imports declined from 75% during 1999 to <1% during 2013. Nearly all shipments during these years were imported for commercial purposes. Imports from Europe and other countries in North America experienced notable increases in volume. Gerbils and hamsters arriving from Europe and chinchillas, guinea pigs, and hamsters arriving from other countries in North America were predominant taxa underlying this trend . After 2003, African-origin imports became sporadic events under the federal permit process. These patterns suggest development of large -scale captive rodent breeding markets abroad for commercial sale in the United States. While the shift from wild-captured imports alleviates many conservation concerns and risks for novel disease emergence, such consolidated sourcing might elevate exposure risks for zoonotic diseases associated with high-density rodent breeding(e.g. , lymphocytic choriomeningitis or salmonellosis). A responsive border health system must periodically re-evaluate importation regulations in conjunction with key

  12. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

    PubMed Central

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-01-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported. PMID:26982178

  13. New host, geographic records, and histopathologic studies of Angiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment.

    PubMed

    Robles, María del Rosario; Kinsella, John M; Galliari, Carlos; Navone, Graciela T

    2016-03-01

    To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis and Angiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylus species parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

  14. Molecular detection and phylogenetic analysis of tick-borne encephalitis virus in rodents captured in the transdanubian region of Hungary.

    PubMed

    Pintér, Réka; Madai, Mónika; Horváth, Győző; Németh, Viktória; Oldal, Miklós; Kemenesi, Gábor; Dallos, Bianka; Bányai, Krisztián; Jakab, Ferenc

    2014-08-01

    Abstract Tick-borne encephalitis virus (TBEV) infection is a common zoonotic disease affecting humans in Europe and Asia. To determine whether TBEV is present in small mammalian hosts in Hungary, liver samples of wild rodents were tested for TBEV RNA. Over a period of 7 years, a total of 405 rodents were collected at five different geographic locations of the Transdanubian region. TBEV nucleic acid was identified in four rodent species: Apodemus agrarius, A. flavicollis, Microtus arvalis, and Myodes glareolus. Out of the 405 collected rodents, 17 small mammals (4.2%) were positive for TBEV. The present study provides molecular evidence and sequence data of TBEV from rodents in Hungary.

  15. Taphonomic alterations by the rodent species woodland vole (Microtus pinetorum) upon human skeletal remains.

    PubMed

    Pokines, James T

    2015-12-01

    This forensic case report describes the taphonomic effects of woodland vole (Microtus pinetorum) upon a set of skeletonized human remains recovered in Massachusetts, USA. Remains of an individual of this rodent species were discovered where it had been nesting inside the human cranium. Fine, parallel grooves indicative of small rodent gnawing were noted on multiple postcranial elements, and all isolated grooves were consistent in size with the incisors of this species. Other taphonomic alterations to these remains include some gnawing damage and dispersal by large carnivores. This case represents the first report of this rodent species affecting human remains.

  16. Rodent models of genetic contributions to motivation to abuse alcohol.

    PubMed

    Crabbe, John C

    2014-01-01

    In summary, there are remarkably few studies focused on the genetic contributions to alcohol's reinforcing values. Almost all such studies examine the two-bottle preference test. Despite the deficiencies I have raised in its interpretation, a rodent genotype's willingness to drink ethanol when water is freely available offers a reasonable aggregate estimate of alcohol's reinforcing value relative to other genotypes (Green and Grahame 2008). As indicated above, however, preference drinking studies will likely never avoid the confounding role of taste preferences and most often yield intake levels not sufficient to yield a pharmacologically significant BAL. Thus, the quest for improved measures of reinforcing value continues. Of the potential motivational factors considered by McClearn in his seminal review in this series, we can safely conclude that rodent alcohol drinking is not primarily directed at obtaining calories. The role of taste (and odor) remains a challenge. McClearn appears to have been correct that especially those genotypes that avoid alcohol are probably doing so based on preingestive sensory cues; however, postingestive consequences are also important. Cunningham's intragastric model shows the role of both preingestional and postingestional modulating factors for the best known examples, the usually nearly absolutely alcohol-avoiding DBA/2J and HAP-2 mice. Much subsequent data reinforce McClearn's earlier conclusion that C57BL/6J mice, at least, do not regulate their intake around a given self-administered dose of alcohol by adjusting their intake. This leaves us with the puzzle of why nearly all genotypes, even those directionally selectively bred for high voluntary intake for many generations, fail to self-administer intoxicating amounts of alcohol. Since McClearn's review, many ingenious assays to index alcohol's motivational effects have been used extensively, and new methods for inducing dependence have supplanted the older ones prevalent in

  17. Experimental plague infection in South African wild rodents.

    PubMed Central

    Shepherd, A. J.; Leman, P. A.; Hummitzsch, D. E.

    1986-01-01

    Susceptibility studies were undertaken to determine the response of some South African wild rodent species to experimental plague (Yersinia pestis) infection. A degree of plague resistance was found in three gerbil species captured in the plague enzootic region of the northern Cape Province, these being the Namaqua gerbil, Desmodillus auricularis, (LD50 1 X 10(6) organisms), the bushveld gerbil, Tatera leucogaster, (LD50 9.1 X 10(5)) and the highveld gerbil, T. brantsii (LD50 4 X 10(2)). Animals from a population of the four-striped mouse, Rhabdomys pumilio, captured in the plague area of Port Elizabeth, proved moderately resistant to experimental plague infection (LD50 1.3 X 10(4)) while those from another population of the same species captured in a plague-free area of the Orange Free State were extremely susceptible (LD50, 5 organisms). The response of both populations however was a heterogeneous one. Marked differences in susceptibility were also found between two populations of multimammate mice, Mastomys natalensis (2n = 32) although both originated from areas outwith the known distribution of plague in southern Africa. The 50% infectious dose was relatively high in T. leucogaster (3.2 X 10(2)) and D. auricularis (1.7 X 10(3)), but was low (2-16 organisms) in the other rodent species tested. The plague antibody response, determined by enzyme-linked immunosorbent assay (ELISA), was extremely short-lived in T. leucogaster, only 10% of inoculated animals remaining seropositive at low titres after 11 weeks. Antibodies persisted for only slightly longer in the sera of T. brantsii which were reinoculated with 2 X 10(3) plague organisms 6 weeks after initial challenge. The demonstration of the existence of both susceptible and resistant populations of R. pumilio and M. natalensis indicates that these species must be considered as potential plague reservoir hosts in parts of South Africa. The results suggest that resistance to plague infection in previously epizootic

  18. Habituation and prepulse inhibition of acoustic startle in rodents.

    PubMed

    Valsamis, Bridget; Schmid, Susanne

    2011-09-01

    The acoustic startle response is a protective response, elicited by a sudden and intense acoustic stimulus. Facial and skeletal muscles are activated within a few milliseconds, leading to a whole body flinch in rodents(1). Although startle responses are reflexive responses that can be reliably elicited, they are not stereotypic. They can be modulated by emotions such as fear (fear potentiated startle) and joy (joy attenuated startle), by non-associative learning processes such as habituation and sensitization, and by other sensory stimuli through sensory gating processes (prepulse inhibition), turning startle responses into an excellent tool for assessing emotions, learning, and sensory gating, for review see( 2, 3). The primary pathway mediating startle responses is very short and well described, qualifying startle also as an excellent model for studying the underlying mechanisms for behavioural plasticity on a cellular/molecular level(3). We here describe a method for assessing short-term habituation, long-term habituation and prepulse inhibition of acoustic startle responses in rodents. Habituation describes the decrease of the startle response magnitude upon repeated presentation of the same stimulus. Habituation within a testing session is called short-term habituation (STH) and is reversible upon a period of several minutes without stimulation. Habituation between testing sessions is called long-term habituation (LTH)(4). Habituation is stimulus specific(5). Prepulse inhibition is the attenuation of a startle response by a preceding non-startling sensory stimulus(6). The interval between prepulse and startle stimulus can vary from 6 to up to 2000 ms. The prepulse can be any modality, however, acoustic prepulses are the most commonly used. Habituation is a form of non-associative learning. It can also be viewed as a form of sensory filtering, since it reduces the organisms' response to a non-threatening stimulus. Prepulse inhibition (PPI) was originally

  19. A fundamental oscillatory state of isolated rodent hippocampus.

    PubMed

    Wu, Chiping; Shen, Hui; Luk, Wah Ping; Zhang, Liang

    2002-04-15

    Population neuronal rhythms of various frequencies are observed in the rodent hippocampus during distinct behavioural states. However, the question of whether the hippocampus exhibits properties of spontaneous rhythms and population synchrony in isolation has not been definitively answered. To address this, we developed a novel preparation for studying neuronal rhythms in a relatively large hippocampal tissue in vitro. We isolated the whole hippocampus from mice up to 28 days postnatal age, removing the dentate gyrus while preserving the functional CA3-to-CA1 connections. Placing the hippocampal isolate in a perfusion chamber for electrophysiological assessment extracellular recordings from the CA1 revealed rhythmic field potential of 0.5 to

  20. Heterochrony and patterns of cranial suture closure in hystricognath rodents

    PubMed Central

    Wilson, Laura A B; Sánchez-Villagra, Marcelo R

    2009-01-01

    Sutures, joints that allow one bone to articulate with another through intervening fibrous connective tissue, serve as major sites of bone expansion during postnatal craniofacial growth in the vertebrate skull and represent an aspect of cranial ontogeny which may exhibit functional and phylogenetic correlates. Suture evolution among hystricognath rodents, an ecologically diverse group represented here by 26 species, is examined using sequence heterochrony methods, i.e. event pairing and parsimov. Although minor nuances in suture closure sequence exist between species, the overall sequence was found to be conserved both across the hystricognath group and, to an increasing degree, within selected clades. At species level, suture closure pattern exhibited a significant positive correlation with patterns previously reported for hominoids. Patterns for most clades revealed the first sutures to close are those contacting the exoccipital, interparietal, and palatine bones. Heterochronic shifts were found along 19 of 35 branches within the hystricognath phylogeny. The number of shifts per node ranged from one to seven events and, overall, involved 21 of 34 suture sites. The topology generated by parsimony analyses of the event pair matrix yielded only one grouping that was congruent with the evolutionary relationships, compiled from morphological and molecular studies, taken as framework. Sutures contacting the exoccipital displayed the highest levels of most complete closure across all species. Level of suture closure is negatively correlated with cranial length (P < 0.05). Differing life history and locomotory strategies are coupled in part with differing suture closure patterns among several species. PMID:19245501

  1. Automated Tracking of Whiskers in Videos of Head Fixed Rodents

    PubMed Central

    Clack, Nathan G.; O'Connor, Daniel H.; Huber, Daniel; Petreanu, Leopoldo; Hires, Andrew; Peron, Simon; Svoboda, Karel; Myers, Eugene W.

    2012-01-01

    We have developed software for fully automated tracking of vibrissae (whiskers) in high-speed videos (>500 Hz) of head-fixed, behaving rodents trimmed to a single row of whiskers. Performance was assessed against a manually curated dataset consisting of 1.32 million video frames comprising 4.5 million whisker traces. The current implementation detects whiskers with a recall of 99.998% and identifies individual whiskers with 99.997% accuracy. The average processing rate for these images was 8 Mpx/s/cpu (2.6 GHz Intel Core2, 2 GB RAM). This translates to 35 processed frames per second for a 640 px×352 px video of 4 whiskers. The speed and accuracy achieved enables quantitative behavioral studies where the analysis of millions of video frames is required. We used the software to analyze the evolving whisking strategies as mice learned a whisker-based detection task over the course of 6 days (8148 trials, 25 million frames) and measure the forces at the sensory follicle that most underlie haptic perception. PMID:22792058

  2. Rodent-borne hantaviruses in Cambodia, Lao PDR, and Thailand.

    PubMed

    Blasdell, Kim; Cosson, Jean François; Chaval, Yannick; Herbreteau, Vincent; Douangboupha, Bounneuang; Jittapalapong, Sathaporn; Lundqvist, Ake; Hugot, Jean-Pierre; Morand, Serge; Buchy, Philippe

    2011-12-01

    In order to evaluate the circulation of hantaviruses present in southeast Asia, a large scale survey of small mammal species was carried out at seven main sites in the region (Cambodia, Lao People's Democratic Republic, and Thailand). Small scale opportunistic trapping was also performed at an eighth site (Cambodia). Using a standard IFA test, IgG antibodies reacting to Hantaan virus antigens were detected at six sites. Antibody prevalence at each site varied from 0 to 5.6% with antibodies detected in several rodent species (Bandicota indica, B. savilei, Maxomys surifer, Mus caroli, M. cookii, Rattus exulans, R. nitidius, R. norvegicus, and R. tanezumi). When site seroprevalence was compared with site species richness, seropositive animals were found more frequently at sites with lower species richness. In order to confirm which hantavirus species were present, a subset of samples was also subjected to RT-PCR. Hantaviral RNA was detected at a single site from each country. Sequencing confirmed the presence of two hantavirus species, Thailand and Seoul viruses, including one sample (from Lao PDR) representing a highly divergent strain of Seoul virus. This is the first molecular evidence of hantavirus in Lao PDR and the first reported L segment sequence data for Thailand virus.

  3. Histamine stimulates neurogenesis in the rodent subventricular zone.

    PubMed

    Bernardino, Liliana; Eiriz, Maria Francisca; Santos, Tiago; Xapelli, Sara; Grade, Sofia; Rosa, Alexandra Isabel; Cortes, Luísa; Ferreira, Raquel; Bragança, José; Agasse, Fabienne; Ferreira, Lino; Malva, João O

    2012-04-01

    Neural stem/progenitor cells present in the subventricular zone (SVZ) are a potential source of repairing cells after injury. Therefore, the identification of novel players that modulate neural stem cells differentiation can have a huge impact in stem cell-based therapies. Herein, we describe a unique role of histamine in inducing functional neuronal differentiation from cultured mouse SVZ stem/progenitor cells. This proneurogenic effect depends on histamine 1 receptor activation and involves epigenetic modifications and increased expression of Mash1, Dlx2, and Ngn1 genes. Biocompatible poly (lactic-co-glycolic acid) microparticles, engineered to release histamine in a controlled and prolonged manner, also triggered robust neuronal differentiation in vitro. Preconditioning with histamine-loaded microparticles facilitated neuronal differentiation of SVZ-GFP cells grafted in hippocampal slices and in in vivo rodent brain. We propose that neuronal commitment triggered by histamine per se or released from biomaterial-derived vehicles may represent a new tool for brain repair strategies.

  4. Enzymatic activity of rodents acclimated to cold and long scotophase

    NASA Astrophysics Data System (ADS)

    Fourie, F. Le R.; Haim, A.

    1980-09-01

    Rodents representative of a diurnal species ( Rhabdomys pumilio) as well as a nocturnal species ( Praomys natalensis) were acclimated to cold (Ta = 8°C) at a photoperiod of LD 12:12 and a long scotophase (LD 8; 16) at a temperature of 25° C(Ta). Control groups were kept for both species at Ta = 25° C and LD 12:12 and winter acclimated individuals were obtained during July and August to serve as further reference. Blood samples obtained from the tail were analysed for enzymes representative of three major biochemical pathways. The enzymatic activity of LDH (glycolytic pathway), MDH (Krebs cycle) and G6PDH (hexose monophosphate shunt, as an indicator of gonadal activity) were monitored to represent metabolic activity of the respective cycles. Cold acclimated as well as winter acclimatized mice revealed similar enzymatic patterns for both species and significant increases in LDH and MDH were recorded with a concurrent decrease in G6PDH activity. Specimens exposed to long scotophase exhibited similar enzymatic patterns for both species studied, but enzymatic activity was higher than those of cold acclimated individuals. From these results it is concluded that cold as well as long scotophase induce metabolic adaptations through biochemical activity in the experimental animals. The effect of long scotophase is assumed to be an important factor in the induction of winter acclimatization.

  5. Experimental osteonecrosis: development of a model in rodents administered alendronate.

    PubMed

    Conte, Nicolau; Spolidorio, Luis Carlos; Andrade, Cleverton Roberto de; Esteves, Jônatas Caldeira; Marcantonio, Elcio

    2016-08-22

    The main objective of this study was to cause bisphosphonate-related osteonecrosis of the jaws to develop in a rodent model. Adult male Holtzman rats were assigned to one of two experimental groups to receive alendronate (AL; 1 mg/kg/week; n = 6) or saline solution (CTL; n = 6). After 60 days of drug therapy, all animals were subjected to first lower molar extraction, and 28 days later, animals were euthanized. All rats treated with alendronate developed osteonecrosis, presenting as ulcers and necrotic bone, associated with a significant infection process, especially at the inter-alveolar septum area and crestal regions. The degree of vascularization, the levels of C-telopeptide cross-linked collagen type I and bone-specific alkaline phosphatase, as well as the bone volume were significantly reduced in these animals. Furthermore, on radiographic analysis, animals treated with alendronate presented evident sclerosis of the lamina dura of the lower first molar alveolar socket associated with decreased radiographic density in this area. These findings indicate that the protocol developed in the present study opens new perspectives and could be a good starting model for future property design.

  6. Evidence for social cooperation in rodents by automated maze

    PubMed Central

    Avital, Avi; Aga-Mizrachi, Shlomit; Zubedat, Salman

    2016-01-01

    Social cooperation is defined as a joint action for mutual benefit that depends on the individual and the counterparts’ behaviors. To gain valid evidence for social cooperation behavior we conducted a series of experiments in our suggested fully automated non-conditioned maze and depicted three major findings: (i) During 18 days of training the rats showed a progressive social learning curve as well as latent social learning; (ii) Examining the perceptual communication between the cooperating partners, we found a correlation between the available perceptual modalities and the social cooperation performance; and (iii) Investigating contextual learning as a competing process to the social cooperation, we found that additional contextual cues impaired the social cooperation performance. In conclusion, our suggested automated cooperation maze is designed to further our understanding of social cooperation under normal conditions, such as decision-making, and to examine the neural basis of social cooperation. A variety of neuropsychiatric disorders are characterized by disruptions in social behavior and social cognition, including depression, autism spectrum disorders, obsessive-compulsive disorder, and schizophrenia. Thus, on the pathological end, our maze for social cooperation evaluation can contribute significantly to the investigation of a wide range of social cooperation impairments in a rodent model. PMID:27378418

  7. Adolescence as a vulnerable period to alter rodent behavior.

    PubMed

    Schneider, Miriam

    2013-10-01

    Adolescence and puberty are highly important periods for postnatal brain maturation. During adolescence, drastic changes of neuronal architecture and function occur that concomitantly lead to distinct behavioral alterations. Unsurprisingly in view of the multitude of ongoing neurodevelopmental processes in the adolescent brain, most adult neuropsychiatric disorders have their roots exactly during this time span. Adolescence and puberty are therefore crucial developmental periods in terms of understanding the causes and mechanisms of adult mental illness. Valid animal models for adolescent behavior and neurodevelopment might offer better insights into the underlying mechanisms and help to identify specific time windows with heightened susceptibility during development. In order to increase the translational value of such models, we urgently need to define the detailed timing of adolescence and puberty in laboratory rodents. The aim of the present review is to provide a more precise delineation of the time course of these developmental periods during postnatal life in rats and mice and to discuss the impact of adolescence and related neurodevelopmental processes on the heightened susceptibility for mental disorders.

  8. OCT-aided anastomosis platform study in the rodent model

    NASA Astrophysics Data System (ADS)

    Huang, Yong; Tong, Dedi; Zhu, Shan; Wu, Lehao; Ibrahim, Zuhaib; Lee, WP Andrew; Brandacher, Gerald; Kang, Jin U.

    2014-02-01

    Anastomosis is one of the most commonly performed procedure in the clinical environment that involves tubular structures, such as blood vessel, lymphatic vessel, seminal duct and ureter. Suture based anastomosis is still the foundation for most basic surgical training and clinical operation, although alternate techniques have been developed and under development. For those tubular-structure-anastomosis, immediate real-time post-operative evaluation of the surgical outcome is critical to the success of surgery. Previously evaluation is mostly based on surgeons' experience. Fourier-domain optical coherence tomography is high-speed, high-resolution noninvasive 3D imaging modality that has been widely used in the biomedical research and clinical study. In this study we used Fourier-domain optical coherence tomography as an evaluation tool for anastomosis of lymphatic vessels, ureter and seminal duct in rodent model. Immediate post-operative and long term surgical site data were collected and analyzed. Critical clinical parameters such as lumen patency, anastomosed site narrowing and suture error detection are provided to surgeons.

  9. A fundamental oscillatory state of isolated rodent hippocampus

    PubMed Central

    Wu, Chiping; Shen, Hui; Luk, Wah Ping; Zhang, Liang

    2002-01-01

    Population neuronal rhythms of various frequencies are observed in the rodent hippocampus during distinct behavioural states. However, the question of whether the hippocampus exhibits properties of spontaneous rhythms and population synchrony in isolation has not been definitively answered. To address this, we developed a novel preparation for studying neuronal rhythms in a relatively large hippocampal tissue in vitro. We isolated the whole hippocampus from mice up to 28 days postnatal age, removing the dentate gyrus while preserving the functional CA3-to-CA1 connections. Placing the hippocampal isolate in a perfusion chamber for electrophysiological assessment extracellular recordings from the CA1 revealed rhythmic field potential of 0.5 to ≤ 4 Hz that occurred spontaneously and propagated along the ventro-dorsal hippocampal axis. We provide convergent evidence, via measurements of extracellular pH and K+, recordings of synaptic and intracellular activities and morphological assessments, verifying that these rhythms were not the consequence of hypoxia. Data obtained via simultaneous extracellular and patch clamp recordings suggest that the spontaneous rhythms represent a summation of GABAergic IPSPs originating from pyramidal neurons, which result from synchronous discharges of GABAergic inhibitory interneurons. Similar spontaneous field rhythms were also observed in the hippocampal isolate prepared from young gerbils and rats. Based on these data, we postulate that the spontaneous rhythms represent a fundamental oscillatory state of the hippocampal circuitry isolated from extra-hippocampal inputs. PMID:11956340

  10. Purification of endothelial cells from rodent brain by immunopanning.

    PubMed

    Zhou, Lu; Sohet, Fabien; Daneman, Richard

    2014-01-01

    This protocol describes the use of immunopanning to purify endothelial cells from the rodent brain. Immunopanning permits the prospective isolation of endothelial cells from nervous tissue by relying on the binding of the endothelial cells to an anti-CD31 antibody adhered to a Petri dish. The cells are viable at the end of this gentle procedure, and they can be analyzed acutely for gene expression or cultured alone or in coculture with other central nervous system (CNS) cell types, including CNS pericytes and CNS astrocytes. This procedure can be used to isolate endothelial cells from either rat or mouse. We have suggested specific antibodies that work for each species. Note that endothelial cells from rats and mice have different morphologies; in general, rat CNS endothelial cells are longer and thinner than mouse CNS endothelial cells. This procedure can also be used to purify endothelial cells from different regions of the CNS, including brain and optic nerve. Dissociation procedures must be optimized for each tissue.

  11. Fathering in Rodents: Neurobiological Substrates and Consequences for Offspring

    PubMed Central

    Bales, Karen L.; Saltzman, Wendy

    2015-01-01

    Paternal care, though rare among mammals, is routinely displayed by several species of rodents. Here we review the neuroanatomical and hormonal bases of paternal behavior, as well as the behavioral and neuroendocrine consequences of paternal behavior for offspring. Fathering behavior is subserved by many of the same neural substrates which are also involved in maternal behavior (for example, the medial preoptic area of the hypothalamus). While gonadal hormones such as testosterone, estrogen, and progesterone, as well as hypothalamic neuropeptides such as oxytocin and vasopressin, and the pituitary hormone prolactin, are implicated in the activation of paternal behavior, there are significant gaps in our knowledge of their actions, as well as pronounced differences between species. Removal of the father in biparental species has long-lasting effects on behavior, as well as on these same neuroendocrine systems, in offspring. Finally, individual differences in paternal behavior can have similarly long-lasting, if more subtle, effects on offspring behavior. Future studies should examine similar outcome measures in multiple species, including both biparental species and closely related uniparental species. Careful phylogenetic analyses of the neuroendocrine systems presumably important to male parenting, as well as their patterns of gene expression, will also be important in establishing the next generation of hypotheses regarding the regulation of male parenting behavior. PMID:26122293

  12. What Can We Learn from Rodents about Prolactin in Humans?

    PubMed Central

    Ben-Jonathan, Nira; LaPensee, Christopher R.; LaPensee, Elizabeth W.

    2008-01-01

    Prolactin (PRL) is a 23-kDa protein hormone that binds to a single-span membrane receptor, a member of the cytokine receptor superfamily, and exerts its action via several interacting signaling pathways. PRL is a multifunctional hormone that affects multiple reproductive and metabolic functions and is also involved in tumorigenicity. In addition to being a classical pituitary hormone, PRL in humans is produced by many tissues throughout the body where it acts as a cytokine. The objective of this review is to compare and contrast multiple aspects of PRL, from structure to regulation, and from physiology to pathology in rats, mice, and humans. At each juncture, questions are raised whether, or to what extent, data from rodents are relevant to PRL homeostasis in humans. Most current knowledge on PRL has been obtained from studies with rats and, more recently, from the use of transgenic mice. Although this information is indispensable for understanding PRL in human health and disease, there is sufficient disparity in the control of the production, distribution, and physiological functions of PRL among these species to warrant careful and judicial extrapolation to humans. PMID:18057139

  13. Protracted brain development in a rodent model of extreme longevity

    PubMed Central

    Penz, Orsolya K.; Fuzik, Janos; Kurek, Aleksandra B.; Romanov, Roman; Larson, John; Park, Thomas J.; Harkany, Tibor; Keimpema, Erik

    2015-01-01

    Extreme longevity requires the continuous and large-scale adaptation of organ systems to delay senescence. Naked mole rats are the longest-living rodents, whose nervous system likely undergoes life-long adaptive reorganization. Nevertheless, neither the cellular organization of their cerebral cortex nor indices of structural neuronal plasticity along extreme time-scales have been established. We find that adult neurogenesis and neuronal migration are not unusual in naked mole rat brains. Instead, we show the prolonged expression of structural plasticity markers, many recognized as being developmentally controlled, and multi-year-long postnatal neuromorphogenesis and spatial synapse refinement in hippocampal and olfactory structures of the naked mole rat brain. Neurophysiological studies on identified hippocampal neurons demonstrated that morphological differentiation is disconnected from the control of excitability in all neuronal contingents regardless of their ability to self-renew. Overall, we conclude that naked mole rats show an extremely protracted period of brain maturation that may permit plasticity and resilience to neurodegenerative processes over their decades-long life span. This conclusion is consistent with the hypothesis that naked mole rats are neotenous, with retention of juvenile characteristics to permit survival in a hypoxic environment, with extreme longevity a consequence of greatly retarded development. PMID:26118676

  14. Protracted brain development in a rodent model of extreme longevity.

    PubMed

    Penz, Orsolya K; Fuzik, Janos; Kurek, Aleksandra B; Romanov, Roman; Larson, John; Park, Thomas J; Harkany, Tibor; Keimpema, Erik

    2015-06-29

    Extreme longevity requires the continuous and large-scale adaptation of organ systems to delay senescence. Naked mole rats are the longest-living rodents, whose nervous system likely undergoes life-long adaptive reorganization. Nevertheless, neither the cellular organization of their cerebral cortex nor indices of structural neuronal plasticity along extreme time-scales have been established. We find that adult neurogenesis and neuronal migration are not unusual in naked mole rat brains. Instead, we show the prolonged expression of structural plasticity markers, many recognized as being developmentally controlled, and multi-year-long postnatal neuromorphogenesis and spatial synapse refinement in hippocampal and olfactory structures of the naked mole rat brain. Neurophysiological studies on identified hippocampal neurons demonstrated that morphological differentiation is disconnected from the control of excitability in all neuronal contingents regardless of their ability to self-renew. Overall, we conclude that naked mole rats show an extremely protracted period of brain maturation that may permit plasticity and resilience to neurodegenerative processes over their decades-long life span. This conclusion is consistent with the hypothesis that naked mole rats are neotenous, with retention of juvenile characteristics to permit survival in a hypoxic environment, with extreme longevity a consequence of greatly retarded development.

  15. Dynamic resting state functional connectivity in awake and anesthetized rodents.

    PubMed

    Liang, Zhifeng; Liu, Xiao; Zhang, Nanyin

    2015-01-01

    Since its introduction, resting-state functional magnetic resonance imaging (rsfMRI) has been a powerful tool for investigating functional neural networks in both normal and pathological conditions. When measuring resting-state functional connectivity (RSFC), most rsfMRI approaches do not consider its temporal variations and thus only provide the averaged RSFC over the scan time. Recently, there has been a surge of interest to investigate the dynamic characteristics of RSFC in humans, and promising results have been yielded. However, our knowledge regarding the dynamic RSFC in animals remains sparse. In the present study we utilized the single-volume co-activation method to systematically study the dynamic properties of RSFC within the networks of infralimbic cortex (IL) and primary somatosensory cortex (S1) in both awake and anesthetized rats. Our data showed that both IL and S1 networks could be decomposed into several spatially reproducible but temporally changing co-activation patterns (CAPs), suggesting that dynamic RSFC was indeed a characteristic feature in rodents. In addition, we demonstrated that anesthesia profoundly impacted the dynamic RSFC of neural circuits subserving cognitive and emotional functions but had less effects on sensorimotor systems. Finally, we examined the temporal characteristics of each CAP, and found that individual CAPs exhibited consistent temporal evolution patterns. Together, these results suggest that dynamic RSFC might be a general phenomenon in vertebrate animals. In addition, this study has paved the way for further understanding the alterations of dynamic RSFC in animal models of brain disorders.

  16. Transgenic rodent assay for quantifying male germ cell mutant frequency.

    PubMed

    O'Brien, Jason M; Beal, Marc A; Gingerich, John D; Soper, Lynda; Douglas, George R; Yauk, Carole L; Marchetti, Francesco

    2014-08-06

    De novo mutations arise mostly in the male germline and may contribute to adverse health outcomes in subsequent generations. Traditional methods for assessing the induction of germ cell mutations require the use of large numbers of animals, making them impractical. As such, germ cell mutagenicity is rarely assessed during chemical testing and risk assessment. Herein, we describe an in vivo male germ cell mutation assay using a transgenic rodent model that is based on a recently approved Organisation for Economic Co-operation and Development (OECD) test guideline. This method uses an in vitro positive selection assay to measure in vivo mutations induced in a transgenic λgt10 vector bearing a reporter gene directly in the germ cells of exposed males. We further describe how the detection of mutations in the transgene recovered from germ cells can be used to characterize the stage-specific sensitivity of the various spermatogenic cell types to mutagen exposure by controlling three experimental parameters: the duration of exposure (administration time), the time between exposure and sample collection (sampling time), and the cell population collected for analysis. Because a large number of germ cells can be assayed from a single male, this method has superior sensitivity compared with traditional methods, requires fewer animals and therefore much less time and resources.

  17. Transgenic Rodent Assay for Quantifying Male Germ Cell Mutant Frequency

    PubMed Central

    O'Brien, Jason M.; Beal, Marc A.; Gingerich, John D.; Soper, Lynda; Douglas, George R.; Yauk, Carole L.; Marchetti, Francesco

    2014-01-01

    De novo mutations arise mostly in the male germline and may contribute to adverse health outcomes in subsequent generations. Traditional methods for assessing the induction of germ cell mutations require the use of large numbers of animals, making them impractical. As such, germ cell mutagenicity is rarely assessed during chemical testing and risk assessment. Herein, we describe an in vivo male germ cell mutation assay using a transgenic rodent model that is based on a recently approved Organisation for Economic Co-operation and Development (OECD) test guideline. This method uses an in vitro positive selection assay to measure in vivo mutations induced in a transgenic λgt10 vector bearing a reporter gene directly in the germ cells of exposed males. We further describe how the detection of mutations in the transgene recovered from germ cells can be used to characterize the stage-specific sensitivity of the various spermatogenic cell types to mutagen exposure by controlling three experimental parameters: the duration of exposure (administration time), the time between exposure and sample collection (sampling time), and the cell population collected for analysis. Because a large number of germ cells can be assayed from a single male, this method has superior sensitivity compared with traditional methods, requires fewer animals and therefore much less time and resources. PMID:25145276

  18. In vivo Optogenetic Stimulation of the Rodent Central Nervous System

    PubMed Central

    Sidor, Michelle M.; Davidson, Thomas J.; Tye, Kay M.; Warden, Melissa R.; Diesseroth, Karl; McClung, Colleen A.

    2015-01-01

    The ability to probe defined neural circuits in awake, freely-moving animals with cell-type specificity, spatial precision, and high temporal resolution has been a long sought tool for neuroscientists in the systems-level search for the neural circuitry governing complex behavioral states. Optogenetics is a cutting-edge tool that is revolutionizing the field of neuroscience and represents one of the first systematic approaches to enable causal testing regarding the relation between neural signaling events and behavior. By combining optical and genetic approaches, neural signaling can be bi-directionally controlled through expression of light-sensitive ion channels (opsins) in mammalian cells. The current protocol describes delivery of specific wavelengths of light to opsin-expressing cells in deep brain structures of awake, freely-moving rodents for neural circuit modulation. Theoretical principles of light transmission as an experimental consideration are discussed in the context of performing in vivo optogenetic stimulation. The protocol details the design and construction of both simple and complex laser configurations and describes tethering strategies to permit simultaneous stimulation of multiple animals for high-throughput behavioral testing. PMID:25651158

  19. [Behavior of Argentine lymphocytic choriomeningitis virus strains in rodents].

    PubMed

    Saavedra, María del Cármen; Ambrosio, Ana M; Riera, Laura; Sabattini, Marta S

    2007-01-01

    The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five strains have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine strains of LCM virus comparing them in relation to the historical strains WE and Armstrong. Regarding the results obtained in tissue culture, when L 929 cells were used, plaque forming units (PFU) were obtained with human and mouse strains, whilst on Vero cells only human strains developed PFU. Differentials characteristics of historical and Argentine strain's plates were not found, neither differences related to the strain's origin. Neither historical nor Argentine strains were lethal to new-born mice giving a persistent infection, that was demonstrated when we inoculated new-born mouse by intracranial route with different strains of LCM virus and virus was isolated from brains harvested at different days post inoculation. The only exception was Cba An 13065 strain that exhibited virulence in new-born mice, only with 0.026 PFU was obtained 1 DL50. All the strains resulted lethal to adult mice. The mouse strains were more virulent than human strains, being Cba An 13065 the most virulent. These results demonstrate a different behavior in tissue culture between human and mouse strains and allow the identification of virulence markers by intracranial inoculation into new-born or adult mice.

  20. Evidence for social cooperation in rodents by automated maze.

    PubMed

    Avital, Avi; Aga-Mizrachi, Shlomit; Zubedat, Salman

    2016-07-05

    Social cooperation is defined as a joint action for mutual benefit that depends on the individual and the counterparts' behaviors. To gain valid evidence for social cooperation behavior we conducted a series of experiments in our suggested fully automated non-conditioned maze and depicted three major findings: (i) During 18 days of training the rats showed a progressive social learning curve as well as latent social learning; (ii) Examining the perceptual communication between the cooperating partners, we found a correlation between the available perceptual modalities and the social cooperation performance; and (iii) Investigating contextual learning as a competing process to the social cooperation, we found that additional contextual cues impaired the social cooperation performance. In conclusion, our suggested automated cooperation maze is designed to further our understanding of social cooperation under normal conditions, such as decision-making, and to examine the neural basis of social cooperation. A variety of neuropsychiatric disorders are characterized by disruptions in social behavior and social cognition, including depression, autism spectrum disorders, obsessive-compulsive disorder, and schizophrenia. Thus, on the pathological end, our maze for social cooperation evaluation can contribute significantly to the investigation of a wide range of social cooperation impairments in a rodent model.

  1. Mechanisms and chemical induction of aneuploidy in rodent germ cells

    SciTech Connect

    Mailhes, J B; Marchetti, F

    2004-10-15

    The objective of this review is to suggest that the advances being made in our understanding of the molecular events surrounding chromosome segregation in non-mammalian and somatic cell models be considered when designing experiments for studying aneuploidy in mammalian germ cells. Accurate chromosome segregation requires the temporal control and unique interactions among a vast array of proteins and cellular organelles. Abnormal function and temporal disarray among these, and others to be inidentified, biochemical reactions and cellular organelles have the potential for predisposing cells to aneuploidy. Although numerous studies have demonstrated that certain chemicals (mainly those that alter microtubule function) can induce aneuploidy in mammalian germ cells, it seems relevant to point out that such data can be influenced by gender, meiotic stage, and time of cell-fixation post-treatment. Additionally, a consensus has not been reached regarding which of several germ cell aneuploidy assays most accurately reflects the human condition. More recent studies have shown that certain kinase, phosphatase, proteasome, and topoisomerase inhibitors can also induce aneuploidy in rodent germ cells. We suggest that molecular approaches be prudently incorporated into mammalian germ cell aneuploidy research in order to eventually understand the causes and mechanisms of human aneuploidy. Such an enormous undertaking would benefit from collaboration among scientists representing several disciplines.

  2. Medial prefrontal cortex role in recognition memory in rodents.

    PubMed

    Morici, Juan Facundo; Bekinschtein, Pedro; Weisstaub, Noelia V

    2015-10-01

    The study of the neurobiology of recognition memory, defined by the integration of the different components of experiences that support recollection of past experiences have been a challenge for memory researches for many years. In the last twenty years, with the development of the spontaneous novel object recognition task and all its variants this has started to change. The features of recognition memory include a particular object or person ("what"), the context in which the experience took place, which can be the arena itself or the location within a particular arena ("where") and the particular time at which the event occurred ("when"). This definition instead of the historical anthropocentric one allows the study of this type of episodic memory in animal models. Some forms of recognition memory that require integration of different features recruit the medial prefrontal cortex. Focusing on findings from spontaneous recognition memory tasks performed by rodents, this review concentrates on the description of previous works that have examined the role that the medial prefrontal cortex has on the different steps of recognition memory. We conclude that this structure, independently of the task used, is required at different memory stages when the task cannot be solved by a single item strategy.

  3. The effects of dietary restriction on oxidative stress in rodents

    PubMed Central

    Walsh, Michael E.; Shi, Yun; Van Remmen, Holly

    2013-01-01

    Oxidative stress is observed during aging and in numerous age-related diseases. Dietary restriction (DR) is a regimen that protects against disease and extends lifespan in multiple species. However, it is unknown how DR mediates its protective effects. One prominent and consistent effect of DR in a number of systems is the ability to reduce oxidative stress and damage. The purpose of this review is to comprehensively examine the hypothesis that dietary restriction reduces oxidative stress in rodents by decreasing reactive oxygen species (ROS) production and increasing antioxidant enzyme activity, leading to an overall reduction of oxidative damage to macromolecules. The literature reveals that the effects of DR on oxidative stress are complex and likely influenced by a variety of factors, including sex, species, tissue examined, types of ROS and antioxidant enzymes examined, and duration of DR. Here we present a comprehensive review of the existing literature on the effect of DR on mitochondrial ROS generation, antioxidant enzymes and oxidative damage. In a majority of studies, dietary restriction had little effect on mitochondrial ROS production or antioxidant activity. On the other hand, DR decreased oxidative damage in the majority of cases. Although the effects of DR on endogenous antioxidants are mixed, we find that glutathione levels are the most likely antioxidant to be increased by dietary restriction, which supports the emerging redox-stress hypothesis of aging. PMID:23743291

  4. Traumatic Brain Injury – Modeling Neuropsychiatric Symptoms in Rodents

    PubMed Central

    Malkesman, Oz; Tucker, Laura B.; Ozl, Jessica; McCabe, Joseph T.

    2013-01-01

    Each year in the US, ∼1.5 million people sustain a traumatic brain injury (TBI). Victims of TBI can suffer from chronic post-TBI symptoms, such as sensory and motor deficits, cognitive impairments including problems with memory, learning, and attention, and neuropsychiatric symptoms such as depression, anxiety, irritability, aggression, and suicidal rumination. Although partially associated with the site and severity of injury, the biological mechanisms associated with many of these symptoms – and why some patients experience differing assortments of persistent maladies – are largely unknown. The use of animal models is a promising strategy for elucidation of the mechanisms of impairment and treatment, and learning, memory, sensory, and motor tests have widespread utility in rodent models of TBI and psychopharmacology. Comparatively, behavioral tests for the evaluation of neuropsychiatric symptomatology are rarely employed in animal models of TBI and, as determined in this review, the results have been inconsistent. Animal behavioral studies contribute to the understanding of the biological mechanisms by which TBI is associated with neurobehavioral symptoms and offer a powerful means for pre-clinical treatment validation. Therefore, further exploration of the utility of animal behavioral tests for the study of injury mechanisms and therapeutic strategies for the alleviation of emotional symptoms are relevant and essential. PMID:24109476

  5. Rodent models in neuroscience research: is it a rat race?

    PubMed Central

    2016-01-01

    ABSTRACT Rodents (especially Mus musculus and Rattus norvegicus) have been the most widely used models in biomedical research for many years. A notable shift has taken place over the last two decades, with mice taking a more and more prominent role in biomedical science compared to rats. This shift was primarily instigated by the availability of a much larger genetic toolbox for mice, particularly embryonic-stem-cell-based targeting technology for gene disruption. With the recent emergence of tools for altering the rat genome, notably genome-editing technologies, the technological gap between the two organisms is closing, and it is becoming more important to consider the physiological, anatomical, biochemical and pharmacological differences between rats and mice when choosing the right model system for a specific biological question. The aim of this short review and accompanying poster is to highlight some of the most important differences, and to discuss their impact on studies of human diseases, with a special focus on neuropsychiatric disorders. PMID:27736744

  6. Rodents and Leptospira transmission risk in Terceira island (Azores).

    PubMed

    Collares-Pereira, M; Mathias, M L; Santos-Reis, M; Ramalhinho, M G; Duarte-Rodrigues, P

    2000-01-01

    The role of rodents as Leptospira renal carriers in Terceira island was evaluated (1993-1995) through kidney culture and serology [microscopic aglutination test (MAT)] of 94 mice and rats. Fifty-nine animals were positive (n = 41 by serology + culturing; n = 11 serology; n = 7 culturing), presenting a wide distribution in man-made and natural areas. House mice had the highest bacteriological (82.9%) and serological (90.9%) rates, being strictly related to serovar arborea. Black rats were involved in the dispersion of all isolated L. interrogans sensu lato serovars (arborea, copenhageni and icterohaemorrhagiae). Logistic regression analysis and non-metric multi-dimensional scaling, relating Leptospira infection with biological and environmental variables, expressed that adult males Mus domesticus, sexually active and living in humid biotopes, mainly above 500 m, are the most likely reservoirs. This study emphasizes the role of house-mice in the epidemiology of leptospirosis in Terceira and the need of reducing the risk of Leptospira transmission through integrated control programmes, primarily focusing on adult house-mice in peri-domestic environments, before the breeding season.

  7. Liver carcinogenesis: Rodent models of hepatocarcinoma and cholangiocarcinoma

    PubMed Central

    Minicis, Samuele De; Kisseleva, Tatiana; Francis, Heather; Baroni, Gianluca Svegliati; Benedetti, Antonio; Brenner, David; Alvaro, Domenico; Alpini, Gianfranco; Marzioni, Marco

    2013-01-01

    Hepatocellular carcinoma and cholangiocarcinoma are primary liver cancers, both represent a growing challenge for clinicians due to their increasing morbidity and mortality. In the last few years a number of in vivo models of hepatocellular carcinoma and cholangiocarcinoma have been developed. The study of these models is providing a significant contribution in unveiling the pathophysiology of primary liver malignancies. They are also fundamental tools to evaluate newly designed molecules to be tested as new potential therapeutic agents in a pre-clinical set. Technical aspects of each model are critical steps, and they should always be considered in order to appropriately interpret the findings of a study or its planning. The purpose of this review is to describe the technical and experimental features of the most significant rodent models, highlighting similarities or differences between the corresponding human diseases. The first part is dedicated to the discussion of models of hepatocellular carcinoma, developed using toxic agents, or through dietary or genetic manipulations. In the second we will address models of cholangiocarcinoma developed in rats or mice by toxin administration, genetic manipulation and/or bile duct incannulation or surgery. Xenograft or syngenic models are also proposed. PMID:23177172

  8. Electrochemical techniques for subsecond neurotransmitter detection in live rodents.

    PubMed

    Hascup, Kevin N; Hascup, Erin R

    2014-08-01

    Alterations in neurotransmission have been implicated in numerous neurodegenerative and neuropsychiatric disorders, including Alzheimer disease, Parkinson disease, epilepsy, and schizophrenia. Unfortunately, few techniques support the measurement of real-time changes in neurotransmitter levels over multiple days, as is essential for ethologic and pharmacodynamic testing. Microdialysis is commonly used for these research paradigms, but its poor temporal and spatial resolution make this technique inadequate for measuring the rapid dynamics (milliseconds to seconds) of fast signaling neurotransmitters, such as glutamate and acetylcholine. Enzymatic microelectrode arrays (biosensors) coupled with electrochemical recording techniques have demonstrated fast temporal resolution (less than 1 s), excellent spatial resolution (micron-scale), low detection limits (≤200 nM), and minimal damage (50 to 100 μm) to surrounding brain tissue. Here we discuss the benefits, methods, and animal welfare considerations of using platinum microelectrodes on a ceramic substrate for enzyme-based electrochemical recording techniques for real-time in vivo neurotransmitter recordings in both anesthetized and awake, freely moving rodents.

  9. Rodent models in depression research: classical strategies and new directions.

    PubMed

    Pollak, Daniela D; Rey, Carlos E; Monje, Francisco J

    2010-05-06

    Depression, among other mood disorders, represents one of the most common health problems worldwide, with steadily increasing incidence and major socio-economic consequences. However, since the knowledge about the underlying pathophysiological principles is still very scanty, depression and other mood disorders are currently diagnosed solely on clinical grounds. Currently used treatment modalities would therefore benefit enormously from the development of alternative therapeutic interventions. The implementation of proper animal models is a prerequisite for increasing the understanding of the neurobiological basis of mood disorders and is paving the way for the discovery of novel therapeutic targets. In the past thirty years, since the seminal description of the Forced Swim Test as a system to probe antidepressant activity in rodents, the use of animals to model depression and antidepressant activity has come a long way. In this review we describe some of the most commonly used strategies, ranging from screening procedures, such as the Forced Swim Test and the Tail Suspension Test and animal models, such as those based upon chronic stress procedures, to genetic approaches. Finally we also discuss some of the inherent limitations and caveats that need to be considered when using animals as models for mental disorders in basic research.

  10. A novel approach to scavenging anesthetic gases in rodent surgery.

    PubMed

    Nesbitt, Jeffrey C; Krageschmidt, Dale A; Blanco, Michael C

    2013-01-01

    Laboratory animal procedures using gas anesthetics may amass elevated waste gas concentrations in operating rooms if controls are not implemented for capturing and removing the vapors. Area sampling using an infrared analyzer indicated isoflurane concentrations likely to exceed occupational exposure guidelines. Our study showed environmental concentrations of oxygen as high as 40% and isoflurane concentrations >100 ppm when no controls or merely passive controls were utilized. These extraneous isoflurane emissions were determined to be originating from the pre-procedural induction process as well as the gas delivery nose cone. A novel waste gas collection cylinder was designed to enclose the gas delivery nose cone and animal head during the administration of anesthetic gases. The vented cylinder utilized a house vacuum to remove the waste anesthetic gases from the surgical field. A commercially available induction chamber designed to be actively and externally exhausted was used to lower concentrations during the induction process. With implementation of local exhaust ventilation controls, waste anesthetic gas concentrations decreased to below recommended occupational exposure levels. In vitro (sham) testing compared favorably to in vivo measurements validating the reduction capability of active ventilation during rodent anesthetic administration. In vivo isoflurane reductions for the induction chamber emissions, the operating room, and the surgeon's breathing zone were 95%, 60%, and 53%, respectively. The same measurements for an in vitro procedure were 98%, 84%, and 87%, respectively.

  11. Repeated evolution of carnivory among Indo-Australian rodents.

    PubMed

    Rowe, Kevin C; Achmadi, Anang S; Esselstyn, Jacob A

    2016-03-01

    Convergent evolution, often observed in island archipelagos, provides compelling evidence for the importance of natural selection as a generator of species and ecological diversity. The Indo-Australian Archipelago (IAA) is the world's largest island system and encompasses distinct biogeographic units, including the Asian (Sunda) and Australian (Sahul) continental shelves, which together bracket the oceanic archipelagos of the Philippines and Wallacea. Each of these biogeographic units houses numerous endemic rodents in the family Muridae. Carnivorous murids, that is those that feed on animals, have evolved independently in Sunda, Sulawesi (part of Wallacea), the Philippines, and Sahul, but the number of origins of carnivory among IAA murids is unknown. We conducted a comprehensive phylogenetic analysis of carnivorous murids of the IAA, combined with estimates of ancestral states for broad diet categories (herbivore, omnivore, and carnivore) and geographic ranges. These analyses demonstrate that carnivory evolved independently four times after overwater colonization, including in situ origins on the Philippines, Sulawesi, and Sahul. In each biogeographic unit the origin of carnivory was followed by evolution of more specialized carnivorous ecomorphs such as vermivores, insectivores, and amphibious rats.

  12. Optimality in the zonation of ammonia detoxification in rodent liver.

    PubMed

    Bartl, Martin; Pfaff, Michael; Ghallab, Ahmed; Driesch, Dominik; Henkel, Sebastian G; Hengstler, Jan G; Schuster, Stefan; Kaleta, Christoph; Gebhardt, Rolf; Zellmer, Sebastian; Li, Pu

    2015-11-01

    The rodent liver eliminates toxic ammonia. In mammals, three enzymes (or enzyme systems) are involved in this process: glutaminase, glutamine synthetase and the urea cycle enzymes, represented by carbamoyl phosphate synthetase. The distribution of these enzymes for optimal ammonia detoxification was determined by numerical optimization. This in silico approach predicted that the enzymes have to be zonated in order to achieve maximal removal of toxic ammonia and minimal changes in glutamine concentration. Using 13 compartments, representing hepatocytes, the following predictions were generated: glutamine synthetase is active only within a narrow pericentral zone. Glutaminase and carbamoyl phosphate synthetase are located in the periportal zone in a non-homogeneous distribution. This correlates well with the paradoxical observation that in a first step glutamine-bound ammonia is released (by glutaminase) although one of the functions of the liver is detoxification by ammonia fixation. The in silico approach correctly predicted the in vivo enzyme distributions also for non-physiological conditions (e.g. starvation) and during regeneration after tetrachloromethane (CCl4) intoxication. Metabolite concentrations of glutamine, ammonia and urea in each compartment, representing individual hepatocytes, were predicted. Finally, a sensitivity analysis showed a striking robustness of the results. These bioinformatics predictions were validated experimentally by immunohistochemistry and are supported by the literature. In summary, optimization approaches like the one applied can provide valuable explanations and high-quality predictions for in vivo enzyme and metabolite distributions in tissues and can reveal unknown metabolic functions.

  13. Small Rodent Cardiac Phantom for Preclinical Ultrasound Imaging.

    PubMed

    Anderson, Tom

    2017-01-01

    Imaging phantoms play a valuable role in the quality control and quality assurance of medical imaging systems. However, for use in the relatively new field of small-animal preclinical imaging, very few have been described in the literature, and even less or none at all are available commercially. Yet, preclinical small animal phantoms offer the possibility of reducing the need for live animals for test and measurement purposes. Human scale cardiac phantoms, both reported in the literature and available commercially, are typically complex devices. Their designs include numerous flow control valves, pumps, and servo motors. These devices are coupled to tissue mimicking materials (TMMs) shaped to replicate the form of cardiac chambers and valves. They are then operated in such a way as to cause the replica TMM heart to move in a lifelike manner. This paper describes the design and construction of a small rodent preclinical cardiac phantom, which is both of a simple design and construction. Using only readily available materials and components, it can be manufactured without the use of workshop facilities, using only hand-tools. Drawings and pictures of the design are presented along with images of the phantom in operation, using a high-frequency preclinical ultrasound scanner.

  14. A New Gustometer for Taste Testing in Rodents

    PubMed Central

    Blonde, Ginger D.; Henderson, Ross P.; Treesukosol, Yada; Hendrick, Paul; Newsome, Ryan; Fletcher, Fred H.; Tang, Te; Donaldson, James A.

    2015-01-01

    In recent years, to circumvent the interpretive limitations associated with intake tests commonly used to assess taste function in rodents, investigators have developed devices called gustometers to deliver small volumes of taste samples and measure immediate responses, thereby increasing confidence that the behavior of the animal is under orosensory control. Most of these gustometers can be used to measure unconditioned licking behavior to stimuli presented for short durations and/or can be used to train the animal to respond to various fluid stimuli differentially so as to obtain a reward and/or avoid punishment. Psychometric sensitivity and discrimination functions can thus be derived. Here, we describe a new gustometer design, successfully used in behavioral experiments, that was guided by our experience with an older version used for over 2 decades. The new computer-controlled gustometer features no dead space in stimulus delivery lines, effective cleaning of the licking substrate, and the ability to measure licking without passing electrical current through the animal. The parts and dimensions are detailed, and the benefits and limitations of certain design features are discussed. Schematics for key circuits are provided as supplemental information. Accordingly, it should be possible to fabricate this device in a fashion customized for one’s needs. PMID:25616763

  15. Automated tracking of whiskers in videos of head fixed rodents.

    PubMed

    Clack, Nathan G; O'Connor, Daniel H; Huber, Daniel; Petreanu, Leopoldo; Hires, Andrew; Peron, Simon; Svoboda, Karel; Myers, Eugene W

    2012-01-01

    We have developed software for fully automated tracking of vibrissae (whiskers) in high-speed videos (>500 Hz) of head-fixed, behaving rodents trimmed to a single row of whiskers. Performance was assessed against a manually curated dataset consisting of 1.32 million video frames comprising 4.5 million whisker traces. The current implementation detects whiskers with a recall of 99.998% and identifies individual whiskers with 99.997% accuracy. The average processing rate for these images was 8 Mpx/s/cpu (2.6 GHz Intel Core2, 2 GB RAM). This translates to 35 processed frames per second for a 640 px×352 px video of 4 whiskers. The speed and accuracy achieved enables quantitative behavioral studies where the analysis of millions of video frames is required. We used the software to analyze the evolving whisking strategies as mice learned a whisker-based detection task over the course of 6 days (8148 trials, 25 million frames) and measure the forces at the sensory follicle that most underlie haptic perception.

  16. In vivo administration of recombinant alphavirus into rodents.

    PubMed

    Lundstrom, Kenneth

    2012-08-01

    The alphaviruses Semliki Forest virus (SFV) and Sindbis virus (SIN) have been used frequently as expression vectors in vitro and in vivo. Usually, these systems consist of replication-deficient vectors that require a helper vector for packaging of recombinant particles. Replication-proficient vectors have also been engineered. Alphaviral vectors can be used as nucleic-acid-based vectors (DNA and RNA) or infectious particles. High-titer viral production is achieved in <2 d. The broad host range of alphaviruses facilitates studies in mammalian and nonmammalian cell lines, primary cells in culture, and in vivo. The strong preference for expression in neuronal cells has made alphaviruses particularly useful in neurobiological studies. Unfortunately, their strong cytotoxic effect on host cells, relatively short-term transient expression patterns, and the reasonably high cost of viral production remain drawbacks. However, novel mutant alphaviruses have shown reduced cytotoxicity and prolonged expression. This protocol describes stereotactic microinjection of recombinant alphavirus into rodents. Administration can be performed without any purification or concentration of viral stocks. However, filter-sterilization is recommended to ensure that cell debris or other contaminants are not present.

  17. Metabolic phenotyping guidelines: assessing glucose homeostasis in rodent models.

    PubMed

    Bowe, James E; Franklin, Zara J; Hauge-Evans, Astrid C; King, Aileen J; Persaud, Shanta J; Jones, Peter M

    2014-09-01

    The pathophysiology of diabetes as a disease is characterised by an inability to maintain normal glucose homeostasis. In type 1 diabetes, this is due to autoimmune destruction of the pancreatic β-cells and subsequent lack of insulin production, and in type 2 diabetes it is due to a combination of both insulin resistance and an inability of the β-cells to compensate adequately with increased insulin release. Animal models, in particular genetically modified mice, are increasingly being used to elucidate the mechanisms underlying both type 1 and type 2 diabetes, and as such the ability to study glucose homeostasis in vivo has become an essential tool. Several techniques exist for measuring different aspects of glucose tolerance and each of these methods has distinct advantages and disadvantages. Thus the appropriate methodology may vary from study to study depending on the desired end-points, the animal model, and other practical considerations. This review outlines the most commonly used techniques for assessing glucose tolerance in rodents and details the factors that should be taken into account in their use. Representative scenarios illustrating some of the practical considerations of designing in vivo experiments for the measurement of glucose homeostasis are also discussed.

  18. Synthetic cathinones and their rewarding and reinforcing effects in rodents

    PubMed Central

    Watterson, Lucas R.; Olive, M. Foster

    2014-01-01

    Synthetic cathinones, colloquially referred to as “bath salts”, are derivatives of the psychoactive alkaloid cathinone found in Catha edulis (Khat). Since the mid-to-late 2000’s, these amphetamine-like psychostimulants have gained popularity amongst drug users due to their potency, low cost, ease of procurement, and constantly evolving chemical structures. Concomitant with their increased use is the emergence of a growing collection of case reports of bizarre and dangerous behaviors, toxicity to numerous organ systems, and death. However, scientific information regarding the abuse liability of these drugs has been relatively slower to materialize. Recently we have published several studies demonstrating that laboratory rodents will readily self-administer the “first generation” synthetic cathinones methylenedioxypyrovalerone (MDPV) and methylone via the intravenous route, in patterns similar to those of methamphetamine. Under progressive ratio schedules of reinforcement, the rank order of reinforcing efficacy of these compounds are MDPV ≥ methamphetamine > methylone. MDPV and methylone, as well as the “second generation” synthetic cathinones α-pyrrolidinovalerophenone (α-PVP) and 4-methylethcathinone (4-MEC), also dose-dependently increase brain reward function. Collectively, these findings indicate that synthetic cathinones have a high abuse and addiction potential and underscore the need for future assessment of the extent and duration of neurotoxicity induced by these emerging drugs of abuse. PMID:25328910

  19. Development of contrast-enhanced rodent imaging using functional CT

    NASA Astrophysics Data System (ADS)

    Liang, Yun; Stantz, Keith M.; Krishnamurthi, Ganapathy; Steinmetz, Rosemary; Hutchins, Gary D.

    2003-05-01

    Micro-computed tomography (microCT) is capable of obtaining high-resolution images of skeletal tissues. However its image contrast among soft tissues remains inadequate for tumor detection. High speed functional computed tomography will be needed to image tumors by employing x-ray contrast medium. The functional microCT development will not only facilitate the image contrast enhancement among different tissues but also provide information of tumor physiology. To demonstrate the feasibility of functional CT in mouse imaging, sequential computed tomography is performed in mice after contrast material administration using a high-speed clinical CT scanner. Although the resolution of the clinical scanner is not sufficient to dissolve the anatomic details of rodents, bulky physiological parameters in major organs such as liver, kidney, pancreas, and ovaries (testicular) can be examined. For data analysis, a two-compartmental model is employed and implemented to characterize the tissue physiological parameters (regional blood flow, capillary permeability, and relative compartment volumes.) The measured contrast dynamics in kidneys are fitted with the compartmental model to derive the kidney tissue physiology. The study result suggests that it is feasible to extract mouse tissue physiology using functional CT imaging technology.

  20. Hantavirus and Arenavirus Antibodies in Persons with Occupational Rodent Exposure, North America

    PubMed Central

    Milazzo, Mary Louise; Armstrong, Lori R.; Childs, James E.; Rollin, Pierre E.; Khabbaz, Rima; Peters, C.J.; Ksiazek, Thomas G.

    2007-01-01

    Rodents are the principal hosts of Sin Nombre virus, 4 other hantaviruses known to cause hantavirus pulmonary syndrome in North America, and the 3 North American arenaviruses. Serum samples from 757 persons who had worked with rodents in North America and handled neotomine or sigmodontine rodents were tested for antibodies against Sin Nombre virus, Whitewater Arroyo virus, Guanarito virus, and lymphocytic choriomeningitis virus. Antibodies against Sin Nombre virus were found in 4 persons, against Whitewater Arroyo virus or Guanarito virus in 2 persons, and against lymphocytic choriomeningitis virus in none. These results suggest that risk for infection with hantaviruses or arenaviruses usually is low in persons whose occupations entail close physical contact with neotomine or sigmodontine rodents in North America. PMID:17553266

  1. Segment Specification for the Payload Segment of the Reusable Reentry Satellite: Rodent Module Version

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) System is composed of the payload segment (PS), vehicle segment (VS), and mission support (MS) segments. This specification establishes the performance, design, development, and test requirements for the RRS Rodent Module (RM).

  2. Detection of Toxoplasma gondii by PCR and Mouse Bioassay in Rodents of Ahvaz District, Southwestern Iran

    PubMed Central

    Saki, J.; Khademvatan, S.

    2014-01-01

    Toxoplasma gondii is obligate coccidian zoonotic parasite. Felidae family is definitive and wide ranges of warm-blooded vertebrates are intermediate hosts for the parasite. Rodents are measured as an important source of T. gondii infection for the definitive host. Thus, this study aimed to investigate Toxoplasm infection in rodents of Ahvaz district, southwest of Iran. A total of 100 rodents (73 Rattus norvegicus, 21 Rattus rattus, and 6 Mus musculus) were collected and studied by GRA6PCR and mouse bioassay. The finding indicated that 6 out of 100 (6%) and 2 out of 100 (2%) samples were positive by PCR and mouse bioassay, respectively. The results show notable chronic infection in the rodent and potential transmission of the infection among animal and men in the region. Accordingly, this study recommended investigating of the T. gondii infection in definitive and other intermediate hosts in other points of Khuzestan province, Southwest, Iran. PMID:24605327

  3. COMPARATIVE MICROARRAY EXPRESSION ANALYSIS OF SELECTED CANCER RELEVANT GENES IN HYPERTENSIVE RESISTANT VERSUS SUSCEPTIBLE RODENT STRAINS

    EPA Science Inventory

    Hypertension and cancer are prevalent diseases. Epidemiological studies suggest that hypertension may increase the long term risk of cancer. Identification of resistance and/or susceptibility genes using rodent models could provide important insights into the management and treat...

  4. Mutualistic interactions between granivorous heteromyid rodents and a preferred food resource, Indian ricegrass (Achnatherum hymenoides)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Granivorous heteromyid rodent species and Indian ricegrass (Achnatherum hymenoides) are both widely distributed throughout North American deserts. The vast majority (~95%) of Indian ricegrass seedling recruitment occurs from seed clusters cached in shallowly-buried scatterhoards by heteromyids, espe...

  5. Leishmania species: Detection and identification by nested PCR assay from skin samples of rodent reservoirs

    PubMed Central

    Akhavan, Amir Ahmad; Mirhendi, Hossein; Khamesipour, Ali; Alimohammadian, Mohammad Hossein; Rassi, Yavar; Bates, Paul; Kamhawi, Shaden; Valenzuela, Jesus G.; Arandian, Mohammad Hossein; Abdoli, Hamid; Jalali-zand, Niloufar; Jafari, Reza; Shareghi, Niloufar; Ghanei, Maryam; Yaghoobi-Ershadi, Mohammad Reza

    2010-01-01

    Many rodent species act as reservoir hosts of zoonotic cutaneous leishmaniasis in endemic areas. In the present study a simple and reliable assay based on nested PCR was developed for the detection and identification of Leishmania parasites from rodent skin samples. We designed Leishmania-specific primers that successfully amplified ITS regions of Leishmania major, Leishmania gerbilli and Leishmania turanica using nested PCR. Out of 95 field collected Rhombomys opimus, 21 were positive by microscopic examination and 48 by nested PCR. The percentage of gerbils infected with L. major, L. gerbilli and L. turanica was 3.2%, 1.1% and 27.4%, respectively. In 15.8% of the rodents, we found mixed natural infections by L. major and L. turanica, 1.1% by L. major and L. gerbilli, and 2.1% by the three species. We concluded that this method is simple and reliable for detecting and identifying Leishmania species circulating in rodent populations. PMID:20566364

  6. Serologic Evidence of Flavivirus Infections in Peridomestic Rodents in Merida, Mexico.

    PubMed

    Cigarroa-Toledo, Nohemi; Talavera-Aguilar, Lourdes G; Baak-Baak, Carlos M; García-Rejón, Julián E; Hernandez-Betancourt, Silvia; Blitvich, Bradley J; Machain-Williams, Carlos

    2016-01-01

    We conducted surveillance for flavivirus infection in peridomestic rodents in Merida, Mexico in 2011-12. We captured 161 rodents inside private residences, using Sherman traps, including 86 house mice (Mus musculus) and 75 black rats (Rattus rattus). Serum from each animal was assayed by plaque reduction neutralization test (PRNT) using two vertebrate-specific flaviviruses (Apoi and Modoc viruses) and five mosquito-borne flaviviruses (dengue 2, dengue 4, St. Louis encephalitis virus, West Nile, and yellow fever viruses). Sixty-one (37.9%) rodents had antibodies that neutralized at least one virus. Prevalences for flaviviruses were 64.0% and 15.1% for black rats and house mice, respectively. None of the PRNT90 titers exceeded 80, and often they were highest for Modoc virus. These data suggest that a subset of rodents had been infected with Modoc virus or a closely related flavivirus that was not included in the PRNT analysis.

  7. Distinct Leishmania Species Infecting Wild Caviomorph Rodents (Rodentia: Hystricognathi) from Brazil

    PubMed Central

    Cássia-Pires, Renata; Boité, Mariana C.; D'Andrea, Paulo S.; Herrera, Heitor M.; Cupolillo, Elisa; Jansen, Ana Maria; Roque, André Luiz R.

    2014-01-01

    Background Caviomorph rodents, some of the oldest Leishmania spp. hosts, are widely dispersed in Brazil. Despite both experimental and field studies having suggested that these rodents are potential reservoirs of Leishmania parasites, not more than 88 specimens were analyzed in the few studies of natural infection. Our hypothesis was that caviomorph rodents are inserted in the transmission cycles of Leishmania in different regions, more so than is currently recognized. Methodology We investigated the Leishmania infection in spleen fragments of 373 caviomorph rodents from 20 different species collected in five Brazilian biomes in a period of 13 years. PCR reactions targeting kDNA of Leishmania sp. were used to diagnose infection, while Leishmania species identification was performed by DNA sequencing of the amplified products obtained in the HSP70 (234) targeting. Serology by IFAT was performed on the available serum of these rodents. Principal findings In 13 caviomorph rodents, DNA sequencing analyses allowed the identification of 4 species of the subgenus L. (Viannia): L. shawi, L. guyanensis, L. naiffi, and L. braziliensis; and 1 species of the subgenus L. (Leishmania): L. infantum. These include the description of parasite species in areas not previously included in their known distribution: L. shawi in Thrichomys inermis from Northeastern Brazil and L. naiffi in T. fosteri from Western Brazil. From the four other positive rodents, two were positive for HSP70 (234) targeting but did not generate sequences that enabled the species identification, and another two were positive only in kDNA targeting. Conclusions/Significance The infection rate demonstrated by the serology (51.3%) points out that the natural Leishmania infection in caviomorph rodents is much higher than that observed in the molecular diagnosis (4.6%), highlighting that, in terms of the host species responsible for maintaining Leishmania species in the wild, our current knowledge represents only the

  8. Small rodents as paratenic or intermediate hosts of carnivore parasites in Berlin, Germany

    PubMed Central

    Maaz, Denny; Demeler, Janina; Ramünke, Sabrina; Antolová, Daniela; Schaper, Roland; von Samson-Himmelstjerna, Georg

    2017-01-01

    Rodents are important intermediate and paratenic hosts for carnivore parasites, including the important zoonotic agents Toxoplasma, Echinococcus and Toxocara. Monitoring of such parasites in rodents can be used to detect increasing risks for human and veterinary public health. Rodents were trapped at four sites in Berlin, two near the city center, two at the periphery. PCRs were conducted to detect Coccidia (target ITS-1) and specifically Toxoplasma gondii (repetitive element) in brain and ascarids (ITS-2) in muscle or brain tissue. During necropsies, metacestodes were collected and identified using ITS-2 and 12S rRNA PCRs. An ELISA to detect antibodies against Toxocara canis ES antigens was performed. Within the 257 examined rodents, the most frequently observed parasite was Frenkelia glareoli predominantly found in Myodes glareolus. T. gondii was only detected in 12 rodents and Microtus spp. (although strongly underrepresented) had a significantly increased chance of being positive. Neither Echinococcus nor typical Taenia parasites of dogs and cats were found but Mesocestoides litteratus and Taenia martis metacestodes were identified which can cause severe peritoneal or ocular cysticercosis in dogs, primates and humans. Using PCR, the ascarids T. canis (n = 8), Toxocara cati (4) and Parascaris sp. (1) were detected predominantly in muscles. Seroprevalence of T. canis was 14.2% and ELISA was thus more sensitive than PCR to detect infection with this parasite. Non-parametric multidimensional scaling and cluster analysis revealed that parasite communities could be grouped into an urban and a peri-urban cluster with high frequency of ascarid-positive rodents in urban and high frequency of F. glareoli in peri-urban sites. Prevalence rates of parasites in rodents with potential impact for human or veterinary public health are considerable and the monitoring of transmission cycles of carnivore parasites in intermediate rodent hosts is recommended to estimate the health

  9. Evaluating social defeat as a model for psychopathology in adult female rodents.

    PubMed

    Solomon, Matia B

    2017-01-02

    Social conflict is a predominant stressor in humans and is associated with increased risk for developing psychological illnesses including depression and anxiety. Overwhelmingly, more women suffer from these disorders, which may be due to increased stress sensitivity. Like humans, rodents experience a myriad of physiological and behavioral sequelae due to prolonged stress exposure. Although the motivation for social conflict may differ between humans and rodents, female rodents may provide an opportunity to explore the underlying mechanisms by which stress confers risk for psychopathology in women. Because most female rodents do not express spontaneous aggression, the majority of basic research examines the physiological and behavioral outcomes of social conflict in male rodents. However, there are instances where female rodents exhibit territorial (California mice and Syrian hamsters) and maternal aggression (rats, mice, and hamsters) creating a venue to examine sex differences in physiology and behavior in response to stress. While many studies rely upon nonsocial behavioral assays (e.g., elevated plus maze, forced swim test) to assess the impact of stress on emotionality, here we primarily focus on behavioral outcomes in social-based assays in rodents. This is critically important given that disruptions in social relationships can be a cause and consequence of neuropsychiatric diseases. Next, we briefly discuss how sex differences in the recruitment of neural circuitry and/or neurochemistry in response to stress may underlie sex differences in neuroendocrine and behavioral stress responses. Finally, the translational value of females in rodent stress models and considerations regarding behavioral interpretations of these models are discussed. © 2016 Wiley Periodicals, Inc.

  10. Adaptation for rodent pollination in Leucospermum arenarium (Proteaceae) despite rapid pollen loss during grooming

    PubMed Central

    Johnson, Christopher Michael; Pauw, Anton

    2014-01-01

    Background and Aims Plants are adapted for rodent pollination in diverse and intricate ways. This study explores an extraordinary example of these adaptations in the pincushion Leucospermum arenarium (Proteaceae) from South Africa. Methods Live trapping and differential exclusion experiments were used to test the role of rodents versus birds and insects as pollinators. To explore the adaptive significance of geoflory, inflorescences were raised above ground level and seed production was compared. Captive rodents and flowers with artificial stigmas were used to test the effect of grooming on the rate of pollen loss. Microscopy, nectar composition analysis and manipulative experiments were used to investigate the bizarre nectar production and transport system. Key Results Differential exclusion of rodents, birds and insects demonstrated the importance of rodents in promoting seed production. Live trapping revealed that hairy-footed gerbils, Gerbillurus paeba, and striped field mice, Rhabdomys pumilio, both carried L. arenarium pollen on their forehead and rostrum, but much larger quantities ended up in faeces as a result of grooming. Terrarium experiments showed that grooming exponentially diminished the pollen loads that they carried. The nectar of L. arenarium was found to be unusually viscous and to be presented in a novel location on the petal tips, where rodents could access it without destroying the flowers. Nectar was produced inside the perianth, but was translocated to the petal tips via capillary ducts. In common with many other rodent-pollinated plants, the flowers are presented at ground level, but when raised to higher positions seed production was not reduced, indicating that selection through female function does not drive the evolution of geoflory. Conclusions Despite the apparent cost of pollen lost to grooming, L. arenarium has evolved remarkable adaptations for rodent pollination and provides the first case of this pollination system in the genus

  11. [Predation and removal of rodents on the seeds with different size and pericarp traits].

    PubMed

    Zhou, Li-biao; Yan, Xing-fu; Wang, Jian-li; Zhou, Yun-feng

    2013-08-01

    A field survey was conducted in the Quercus wutaishanica shrubs in Liupan Mountains of Ningxia, Northwest China to study the predation and removal of rodents on the seeds of Q. wutaishanica, Prunus salicina and Pinus armandii, aimed to explore the effects of seed size and pericarp traits on the predation and removal behaviors of rodents. The in situ seed predation rates of smaller Q. wutaishanica seeds and P. armandii seeds were significantly higher than those of larger Q. wutaishanica seeds and P. salicina seeds. The P. salicina seeds with hard and thick pericarp (endocarp) had the highest predation rate and hoarding rate after the removal by rodents. The movement distance of larger Q. wutaishanica seeds during predation events was the longest (3.10 m), and the seed hoarding distance of this species (6.48 m) was significantly longer than that of the three other types of seeds. Over 80% of sites were used as the predation sites by rodents for the seeds, except that the P. salicina seeds contained only a single seed and the cache sites contained a single seed accounted for over 90% for all types of seeds. Few predation and cache sites containing over two seeds were detected. Higher proportion of P. armandii seeds were predated in microhabitats except at the base of shrubs and in the holes after removal by rodent, while the seeds of other three types were predated mainly at the base of shrubs and in the holes after removal by rodents. The seed hoarding patterns after removal by rodents were primarily determined by pericarp traits, and higher proportion of soil burial that the rodents hoarded seeds with hard pericarp (endocarp) was detected.

  12. Mites infesting commensal rodents in Shebin El Kom, Menoufia G., Egypt.

    PubMed

    Bakr, M E; Morsy, T A; Nassef, N E; el Meligi, M A

    1995-12-01

    Rodent populations markedly increased in many Egyptian Governorates particularly commensal ones which live in close association with man and his domestic animals. In this paper, commensal rodents; M. musculus R. r. alexandrinus, and R. norvegicus were examined for the mites infesting them. Four species of mites were recovered; Ornithonyssus bacoti; Laelaps nuttalli, Dermanyssus gallinae and Allodermanyssus sanguineus. The medical and economic importance was discussed. It was concluded that mites and their environmental problem should be tackled.

  13. South American mammal zoogeography: evidence from convergent evolution in desert rodents.

    PubMed

    Mares, M A

    1975-05-01

    Current theories regarding colonization of South America by mammals are divided between those supported by fossil evidence, which suggest the original mammal fauna of the isolated continent was augmented by early immigrants (primates, caviomorph rodents, and later, procyonids) with a final large influx of northern mammals occurring with the formation of the Panama land bridge, and an opposing view which states that the purported "recent invaders" are too taxonomically and ecologically differentiated to have colonized since the land bridge arose. The second theory suggests that most extant mammals entered before the Plio-Pleistocene land connection. An analysis of degree of physiological adaptation, natural history, distribution patterns, and a multivariate assessment of convergent evolution of Monte Desert rodents indicate that South American cricetine rodents are not highly specialized for desert life. Their degree of adaptation could be accounted for, in large part, by adaptations for arid or semiarid Andean habitats. No Monte Desert rodent has developed the specialized desert traits that have evolved in most desert rodent faunas of the world, although extinct marsupials similar to living bipedal desert rodents were present in the Monte as recently as late Pliocene. Evidence suggests that Monte caviomorphs have been associated with the desert for a longer period than cricetines, and that the latter represent a fairly recent invasion of the Monte Desert. The data thus support the first hypothesis of South American mammal colonization.

  14. Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt.

    PubMed

    Soliman, A K; Botros, B A; Ksiazek, T G; Hoogstraal, H; Helmy, I; Morrill, J C

    1989-10-01

    A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% (n = 83) of Acomys spp. Collectively, rodents captured in the Nile Delta had a higher prevalence (mean 24% (n = 787] than those captured in the Nile Valley (mean 4% (n = 650]. Antibody to R. typhi was detected in rodents collected in all port cities: ismailiya, 13%; Port Said, 9%; Suez, 9%; Safaga, 16%; Quseir, 32% and Alexandria, 34%. These data showed evidence of R. typhi infection among rodents in widespread geographic localities of Egypt and suggested that infected rodents may be a source of human infections.

  15. Hantavirus pulmonary syndrome and rodent reservoirs in the savanna-like biome of Brazil's southeastern region.

    PubMed

    Limongi, J E; Oliveira, R C; Guterres, A; Costa Neto, S F; Fernandes, J; Vicente, L H B; Coelho, M G; Ramos, V N; Ferreira, M S; Bonvicino, C R; D'Andrea, P S; Lemos, E R S

    2016-04-01

    This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT-PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50-83·7%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

  16. Perceptual and neural responses to sweet taste in humans and rodents

    PubMed Central

    Lemon, Christian H.

    2015-01-01

    Introduction This mini-review discusses some of the parallels between rodent neurophysiological and human psychophysical data concerning temperature effects on sweet taste. Methods and Purpose “Sweet” is an innately rewarding taste sensation that is associated in part with foods that contain calories in the form of sugars. Humans and other mammals can show unconditioned preference for select sweet stimuli. Such preference is poised to influence diet selection and, in turn, nutritional status, which underscores the importance of delineating the physiological mechanisms for sweet taste with respect to their influence on human health. Advances in our knowledge of the biology of sweet taste in humans have arisen in part through studies on mechanisms of gustatory processing in rodent models. Along this line, recent work has revealed there are operational parallels in neural systems for sweet taste between mice and humans, as indexed by similarities in the effects of temperature on central neurophysiological and psychophysical responses to sucrose in these species. Such association strengthens the postulate that rodents can serve as effective models of particular mechanisms of appetitive taste processing. Data supporting this link are discussed here, as are rodent and human data that shed light on relationships between mechanisms for sweet taste and ingestive disorders, such as alcohol abuse. Results and Conclusions Rodent models have utility for understanding mechanisms of taste processing that may pertain to human flavor perception. Importantly, there are limitations to generalizing data from rodents, albeit parallels across species do exist. PMID:26388965

  17. Indirect food web interactions mediated by predator-rodent dynamics: relative roles of lemmings and voles.

    PubMed

    Ims, Rolf A; Henden, John-André; Thingnes, Anders V; Killengreen, Siw T

    2013-01-01

    Production cycles in birds are proposed as prime cases of indirect interactions in food webs. They are thought to be driven by predators switching from rodents to bird nests in the crash phase of rodent population cycles. Although rodent cycles are geographically widespread and found in different rodent taxa, bird production cycles appear to be most profound in the high Arctic where lemmings dominate. We hypothesized that this may be due to arctic lemmings inducing stronger predator responses than boreal voles. We tested this hypothesis by estimating predation rates in dummy bird nests during a rodent cycle in low-Arctic tundra. Here, the rodent community consists of a spatially variable mix of one lemming (Lemmus lemmus) and two vole species (Myodes rufocanus and Microtus oeconomus) with similar abundances. In consistence with our hypothesis, lemming peak abundances predicted well crash-phase nest predation rates, whereas the vole abundances had no predictive ability. Corvids were found to be the most important nest predators. Lemmings appear to be accessible to the whole predator community which makes them particularly powerful drivers of food web dynamics.

  18. Molecular and Paleontological Evidence for a Post-Cretaceous Origin of Rodents

    PubMed Central

    Wu, Shaoyuan; Wu, Wenyu; Zhang, Fuchun; Ye, Jie; Ni, Xijun; Sun, Jimin; Edwards, Scott V.; Meng, Jin; Organ, Chris L.

    2012-01-01

    The timing of the origin and diversification of rodents remains controversial, due to conflicting results from molecular clocks and paleontological data. The fossil record tends to support an early Cenozoic origin of crown-group rodents. In contrast, most molecular studies place the origin and initial diversification of crown-Rodentia deep in the Cretaceous, although some molecular analyses have recovered estimated divergence times that are more compatible with the fossil record. Here we attempt to resolve this conflict by carrying out a molecular clock investigation based on a nine-gene sequence dataset and a novel set of seven fossil constraints, including two new rodent records (the earliest known representatives of Cardiocraniinae and Dipodinae). Our results indicate that rodents originated around 61.7–62.4 Ma, shortly after the Cretaceous/Paleogene (K/Pg) boundary, and diversified at the intraordinal level around 57.7–58.9 Ma. These estimates are broadly consistent with the paleontological record, but challenge previous molecular studies that place the origin and early diversification of rodents in the Cretaceous. This study demonstrates that, with reliable fossil constraints, the incompatibility between paleontological and molecular estimates of rodent divergence times can be eliminated using currently available tools and genetic markers. Similar conflicts between molecular and paleontological evidence bedevil attempts to establish the origination times of other placental groups. The example of the present study suggests that more reliable fossil calibration points may represent the key to resolving these controversies. PMID:23071573

  19. Zoonotic pathogens in Atlantic Forest wild rodents in Brazil: Bartonella and Coxiella infections.

    PubMed

    Rozental, Tatiana; Ferreira, Michelle Santos; Guterres, Alexandro; Mares-Guia, Maria Angélica; Teixeira, Bernardo R; Gonçalves, Jonathan; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sergio; de Lemos, Elba Regina Sampaio

    2017-04-01

    Zoonotic pathogens comprise a significant and increasing fraction of all emerging and re-emerging infectious diseases that plague humans. Identifying host species is one of the keys to controlling emerging infectious diseases. From March 2007 until April 2012, we collected a total of 131 wild rodents in eight municipalities of Rio de Janeiro, Brazil. We investigated these rodents for infection with Coxiella burnetii, Bartonella spp. and Rickettsia spp. In total, 22.1% (29/131) of the rodents were infected by at least one pathogen; co-infection was detected in 1.5% (2/131) of rodents. Coxiella burnetii was detected in 4.6% (6/131) of the wild animals, 17.6% of the rodents harbored Bartonella spp. No cases of Rickettsia were identified. Bartonella doshiae and Bartonella vinsonii were the species found on the wild mammals. This report is the first to note C. burnetii, B. doshiae and B. vinsonii natural infections in Atlantic Forest wild rodents in Brazil. Our work highlights the potential risk of transmission to humans, since most of the infected specimens belong to generalist species that live near human dwellings.

  20. A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

    USGS Publications Warehouse

    Luis, Angela D.; Hayman, David T.S.; O'Shea, Thomas J.; Cryan, Paul M.; Gilbert, Amy T.; Pulliam, Juliet R.C.; Mills, James N.; Timonin, Mary E.; Willis, Craig K.R.; Cunningham, Andrew A.; Fooks, Anthony R.; Rupprecht, Charles E.; Wood, James L.N.; Webb, Colleen T.

    2013-01-01

    Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs.

  1. Evidence of multiple zoonotic agents in a wild rodent community in the eastern Sierra Nevada.

    PubMed

    Adjemian, Jennifer Zipser; Adjemian, Michael K; Foley, Patrick; Chomel, Bruno B; Kasten, Rickie W; Foley, Janet E

    2008-07-01

    This study aimed to describe the occurrence of Yersinia pestis, Rickettsia rickettsii, Anaplasma phagocytophilum, and ectoparasites in a wild rodent community in the eastern Sierra Nevada. From May to September 2006, rodents were live-trapped, examined for ectoparasites, and blood was collected. All rodents were serologically tested for antibodies to Y. pestis, R. rickettsii, and A. phagocytophilum; in addition, blood samples and ectoparasites were tested by PCR to detect the presence of these zoonotic agents. Overall, 89 rodents, 46 fleas, and four ticks were collected. Antibody prevalence rates observed for rodents were 14% for R. rickettsii or antigenically related spotted-fever group rickettsiae, and 8% for A. phagocytophilum. No samples were positive for antibodies to Y. pestis. Positive PCR results included one yellow-pine chipmunk for Y. pestis (CT=32.8), one golden-mantled ground squirrel for R. rickettsii (CT=33), and one flea found to be co-infected with both R. rickettsii (CT=17) and A. phagocytophilum (CT=36). The results of this study provide evidence of multiple zoonoses overlapping within a single, located rodent community.

  2. Relationships between Rodent White Adipose Fat Pads and Human White Adipose Fat Depots

    PubMed Central

    Chusyd, Daniella E.; Wang, Donghai; Huffman, Derek M.; Nagy, Tim R.

    2016-01-01

    The objective of this review was to compare and contrast the physiological and metabolic profiles of rodent white adipose fat pads with white adipose fat depots in humans. Human fat distribution and its metabolic consequences have received extensive attention, but much of what has been tested in translational research has relied heavily on rodents. Unfortunately, the validity of using rodent fat pads as a model of human adiposity has received less attention. There is a surprisingly lack of studies demonstrating an analogous relationship between rodent and human adiposity on obesity-related comorbidities. Therefore, we aimed to compare known similarities and disparities in terms of white adipose tissue (WAT) development and distribution, sexual dimorphism, weight loss, adipokine secretion, and aging. While the literature supports the notion that many similarities exist between rodents and humans, notable differences emerge related to fat deposition and function of WAT. Thus, further research is warranted to more carefully define the strengths and limitations of rodent WAT as a model for humans, with a particular emphasis on comparable fat depots, such as mesenteric fat. PMID:27148535

  3. Hypericum perforatum as a cognitive enhancer in rodents: A meta-analysis

    PubMed Central

    Ben-Eliezer, Daniel; Yechiam, Eldad

    2016-01-01

    Considered an antidepressant and anti-anxiety agent, Hypericum perforatum affects multiple neurotransmitters in a non-competitive synergistic manner, and may have nootropic potential. We quantitatively reviewed the pre-clinical literature to examine if there is a cognitive-enhancing effect of H. perforatum in healthy rodents. Additionally, within these studies, we compared the effects observed in intact rodents versus those whose performance has been impaired, mostly through stress manipulations. The meta-analysis incorporated studies that examined the effect of H. perforatum versus placebo on memory indices of task performance. All analyses were based on weighting different studies according to their inverse variance. Thirteen independent studies (published 2000–2014) involving 20 experimental comparisons met our inclusion criteria. The results showed a large positive effect of H. perforatum on cognitive performance for intact, healthy rodents (d = 1.11), though a larger effect emerged for stress-impaired rodents (d = 3.10 for restraint stress). The positive effect on intact rodents was observed in tasks assessing reference memory as well as working memory, and was not moderated by the type of memory or motivation (appetitive versus aversive). Thus, while primarily considered as a medication for depression, H. perforatum shows considerable nootropic potential in rodents. PMID:27762349

  4. Comparative Pathobiology of Environmentally Induced Lung Cancers in Humans and Rodents

    PubMed Central

    Pandiri, Arun

    2014-01-01

    Lung cancer is the number one cause of cancer-related deaths in humans worldwide. Environmental factors play an important role in the epidemiology of these cancers. Rodents are the most common experimental model to study human lung cancers and are frequently used in bioassays to identify environmental exposure hazards associated with lung cancer. Lung tumors in rodents are common, particularly in certain strains of mice. Rodent lung tumors are predominantly bronchioloalveolar carcinomas and usually follow a progressive continuum of hyperplasia to adenoma to carcinoma. Human lung cancers are phenotypically more diverse and broadly constitute 2 types: small cell lung cancers or non-small cell lung cancers. Rodent lung tumors resulting from exposure to environmental agents are comparable to certain adenocarcinomas that are a subset of human non-small cell lung cancers. Human pulmonary carcinomas differ from rodent lung tumors by exhibiting greater morphologic heterogeneity (encompassing squamous cell, neuroendocrine, mucinous, sarcomatoid, and multiple cell combinations), higher metastatic rate, higher stromal response, aggressive clinical behavior, and lack of a clear continuum of proliferative lesions. In spite of these differences, rodent lung tumors recapitulate several fundamental aspects of human lung tumor biology at the morphologic and molecular level especially in lung cancers resulting from exposure to environmental carcinogens. PMID:25351923

  5. Hypericum perforatum as a cognitive enhancer in rodents: A meta-analysis.

    PubMed

    Ben-Eliezer, Daniel; Yechiam, Eldad

    2016-10-20

    Considered an antidepressant and anti-anxiety agent, Hypericum perforatum affects multiple neurotransmitters in a non-competitive synergistic manner, and may have nootropic potential. We quantitatively reviewed the pre-clinical literature to examine if there is a cognitive-enhancing effect of H. perforatum in healthy rodents. Additionally, within these studies, we compared the effects observed in intact rodents versus those whose performance has been impaired, mostly through stress manipulations. The meta-analysis incorporated studies that examined the effect of H. perforatum versus placebo on memory indices of task performance. All analyses were based on weighting different studies according to their inverse variance. Thirteen independent studies (published 2000-2014) involving 20 experimental comparisons met our inclusion criteria. The results showed a large positive effect of H. perforatum on cognitive performance for intact, healthy rodents (d = 1.11), though a larger effect emerged for stress-impaired rodents (d = 3.10 for restraint stress). The positive effect on intact rodents was observed in tasks assessing reference memory as well as working memory, and was not moderated by the type of memory or motivation (appetitive versus aversive). Thus, while primarily considered as a medication for depression, H. perforatum shows considerable nootropic potential in rodents.

  6. Molecular and paleontological evidence for a post-Cretaceous origin of rodents.

    PubMed

    Wu, Shaoyuan; Wu, Wenyu; Zhang, Fuchun; Ye, Jie; Ni, Xijun; Sun, Jimin; Edwards, Scott V; Meng, Jin; Organ, Chris L

    2012-01-01

    The timing of the origin and diversification of rodents remains controversial, due to conflicting results from molecular clocks and paleontological data. The fossil record tends to support an early Cenozoic origin of crown-group rodents. In contrast, most molecular studies place the origin and initial diversification of crown-Rodentia deep in the Cretaceous, although some molecular analyses have recovered estimated divergence times that are more compatible with the fossil record. Here we attempt to resolve this conflict by carrying out a molecular clock investigation based on a nine-gene sequence dataset and a novel set of seven fossil constraints, including two new rodent records (the earliest known representatives of Cardiocraniinae and Dipodinae). Our results indicate that rodents originated around 61.7-62.4 Ma, shortly after the Cretaceous/Paleogene (K/Pg) boundary, and diversified at the intraordinal level around 57.7-58.9 Ma. These estimates are broadly consistent with the paleontological record, but challenge previous molecular studies that place the origin and early diversification of rodents in the Cretaceous. This study demonstrates that, with reliable fossil constraints, the incompatibility between paleontological and molecular estimates of rodent divergence times can be eliminated using currently available tools and genetic markers. Similar conflicts between molecular and paleontological evidence bedevil attempts to establish the origination times of other placental groups. The example of the present study suggests that more reliable fossil calibration points may represent the key to resolving these controversies.

  7. Middle Eocene rodents from Peruvian Amazonia reveal the pattern and timing of caviomorph origins and biogeography.

    PubMed

    Antoine, Pierre-Olivier; Marivaux, Laurent; Croft, Darin A; Billet, Guillaume; Ganerød, Morgan; Jaramillo, Carlos; Martin, Thomas; Orliac, Maëva J; Tejada, Julia; Altamirano, Ali J; Duranthon, Francis; Fanjat, Grégory; Rousse, Sonia; Gismondi, Rodolfo Salas

    2012-04-07

    The long-term isolation of South America during most of the Cenozoic produced a highly peculiar terrestrial vertebrate biota, with a wide array of mammal groups, among which caviomorph rodents and platyrrhine primates are Mid-Cenozoic immigrants. In the absence of indisputable pre-Oligocene South American rodents or primates, the mode, timing and biogeography of these extraordinary dispersals remained debated. Here, we describe South America's oldest known rodents, based on a new diverse caviomorph assemblage from the late Middle Eocene (approx. 41 Ma) of Peru, including five small rodents with three stem caviomorphs. Instead of being tied to the Eocene/Oligocene global cooling and drying episode (approx. 34 Ma), as previously considered, the arrival of caviomorphs and their initial radiation in South America probably occurred under much warmer and wetter conditions, around the Mid-Eocene Climatic Optimum. Our phylogenetic results reaffirm the African origin of South American rodents and support a trans-Atlantic dispersal of these mammals during Middle Eocene times. This discovery further extends the gap (approx. 15 Myr) between first appearances of rodents and primates in South America.

  8. Diversity of Enterocytozoon bieneusi genotypes among small rodents in southwestern Poland.

    PubMed

    Perec-Matysiak, Agnieszka; Buńkowska-Gawlik, Katarzyna; Kváč, Martin; Sak, Bohumil; Hildebrand, Joanna; Leśniańska, Kinga

    2015-12-15

    Diversity of Enterocytozoon bieneusi genotypes in wild small rodent populations still remains incomplete and only few molecular studies have been conducted among these hosts. Therefore, the aim of this study was to determine whether small rodents, i.e., Apodemus agrarius, Apodemus flavicollis, Mus musculus and Myodes glareolus act as hosts of E. bieneusi and can play an important role in spore spreading in the environment of south-western Poland. Molecular analyses were conducted to determine pathogen genotypes. A total of 191 fecal and 251 spleen samples collected from 311 rodent individuals were examined for the occurrence of E. bieneusi by PCR amplifying ITS gene. The overall prevalence of E. bieneusi in rodent samples was 38.9%. The nucleotide sequences of ITS region of E. bieneusi revealed the presence a total of 12 genotypes with two being already known, i.e., D and gorilla 1 genotypes. The remaining ten are novel genotypes (WR1-WR10) which segregated into three groups in a neighbor joining phylogeny. This study reports for the first time E. bieneusi occurrence in wild living rodents in Poland and shows extensive genetic diversity within E. bieneusi isolates of rodent origin.

  9. Leishmania infantum in wild rodents: reservoirs or just irrelevant incidental hosts?

    PubMed

    Navea-Pérez, H M; Díaz-Sáez, V; Corpas-López, V; Merino-Espinosa, G; Morillas-Márquez, F; Martín-Sánchez, J

    2015-06-01

    Wild rodents constitute a very large biomass of potential reservoirs for Leishmania spp. Therefore, an epidemiological study was carried out in a well-known focus of canine leishmaniasis from southern Spain, with the objective of detecting and characterizing Leishmania infantum infection in wild rodents. Blood, liver, spleen, bone marrow, and skin from 37 rodents (24 Apodemus sylvaticus, 9 Rattus rattus, and 4 Mus musculus) were analyzed by optical microscopy, culture, and two different polymerase chain reactions. L. infantum DNA was found in 27% (10 out of 37) of the trapped rodents, in a variety of tissues: bone marrow, spleen, or healthy skin (ear lobe). High prevalences of L. infantum infection were found in the three investigated rodent species. The presence of other trypanosomatids was also evidenced. These rodent species are abundant, widely distributed in Europe, and have a long enough lifespan to overcome the low sandfly activity season. They live in a suitable habitat for sandflies and serve as blood sources for these insects, which can become infected when induced to feed on Leishmania-infected animals. Whether they are reservoirs or just irrelevant incidental hosts, it is clear that the epidemiology of L. infantum is more complex than previously thought, and so is its control. The classic epidemiological cycle dog-sandfly-human is turning into a network of animal species that collaborate with the dog in the maintenance of the parasite under natural conditions and probably showing local differences.

  10. Zoonotic Bartonella species in wild rodents in the state of Mato Grosso do Sul, Brazil.

    PubMed

    Favacho, Alexsandra Rodrigues de Mendonça; Andrade, Marcelle Novaes; de Oliveira, Renata Carvalho; Bonvicino, Cibele Rodrigues; D'Andrea, Paulo Sergio; de Lemos, Elba Regina Sampaio

    2015-01-01

    Several rodent-associated Bartonella species cause disease in humans but little is known about their epidemiology in Brazil. The presence of Bartonella spp. in wild rodents captured in two municipalities of the Mato Grosso do Sul state was assessed by polymerase chain reaction (PCR). Fragments of heart tissue from 42 wild rodents were tested using primers targeting the Bartonella 16S-23S intergenic transcribed spacer (ITS) region and citrate synthase gltA gene. The wild rodents were identified based on external and cranial morphology and confirmed at species level by mitochondrial DNA (cytochrome B) sequencing and karyotype. Overall, 42.9% (18/42) of the wild rodents were PCR positive for Bartonella spp.: Callomys callosus (04), Cerradomys maracajuensis (04), Hylaeamus megacephalus (01), Necromys lasiurus (06), Nectomys squamipes (01), Oecomys catherinae (01) and Oxymycterus delator (01). Bartonella vinsonii subsp. arupensis was detected in N. lasiurus (46%) and C. callosus (21%) captured in the two study sites. We reported the first molecular detection of B. vinsonii subsp. arupensis in different species of wild rodents collected in the Brazilian territory. Further studies are needed to examine the role of these mammals in the eco-epidemiology of bartonellosis in Brazil.

  11. Bartonella genotypes in fleas (insecta: siphonaptera) collected from rodents in the negev desert, Israel.

    PubMed

    Morick, Danny; Krasnov, Boris R; Khokhlova, Irina S; Shenbrot, Georgy I; Kosoy, Michael Y; Harrus, Shimon

    2010-10-01

    Fleas collected from rodents in the Negev Desert in southern Israel were molecularly screened for Bartonella species. A total of 1,148 fleas, collected from 122 rodents belonging to six species, were pooled in 245 pools based on flea species, sex, and rodent host species. Two Bartonella gene fragments, corresponding to RNA polymerase B (rpoB) and citrate synthase (gltA), were targeted, and 94 and 74 flea pools were found positive by PCR, respectively. The Bartonella 16S-23S internal transcribed spacer (ITS) region was also targeted, and 66 flea pools were found to be positive by PCR. Sixteen different Bartonella gltA genotypes were detected in 94 positive flea pools collected from 5 different rodent species, indicating that fleas collected from each rodent species can harbor several Bartonella genotypes. Based on gltA analysis, identified Bartonella genotypes were highly similar or identical to strains previously detected in rodent species from different parts of the world. A gltA fragment 100% similar to Bartonella henselae was detected in one flea pool. Another 2 flea pools contained gltA fragments that were closely related to B. henselae (98% similarity). The high sequence similarities to the zoonotic pathogen B. henselae warrant further investigation.

  12. Joshua tree (Yucca brevifolia) seeds are dispersed by seed-caching rodents

    USGS Publications Warehouse

    Vander Wall, S. B.; Esque, T.; Haines, D.; Garnett, M.; Waitman, B.A.

    2006-01-01

    Joshua tree (Yucca brevifolia) is a distinctive and charismatic plant of the Mojave Desert. Although floral biology and seed production of Joshua tree and other yuccas are well understood, the fate of Joshua tree seeds has never been studied. We tested the hypothesis that Joshua tree seeds are dispersed by seed-caching rodents. We radioactively labelled Joshua tree seeds and followed their fates at five source plants in Potosi Wash, Clark County, Nevada, USA. Rodents made a mean of 30.6 caches, usually within 30 m of the base of source plants. Caches contained a mean of 5.2 seeds buried 3-30 nun deep. A variety of rodent species appears to have prepared the caches. Three of the 836 Joshua tree seeds (0.4%) cached germinated the following spring. Seed germination using rodent exclosures was nearly 15%. More than 82% of seeds in open plots were removed by granivores, and neither microsite nor supplemental water significantly affected germination. Joshua tree produces seeds in indehiscent pods or capsules, which rodents dismantle to harvest seeds. Because there is no other known means of seed dispersal, it is possible that the Joshua tree-rodent seed dispersal interaction is an obligate mutualism for the plant.

  13. Variable effects of host characteristics on species richness of flea infracommunities in rodents from three continents.

    PubMed

    Kiffner, Christian; Stanko, Michal; Morand, Serge; Khokhlova, Irina S; Shenbrot, Georgy I; Laudisoit, Anne; Leirs, Herwig; Hawlena, Hadas; Krasnov, Boris R

    2014-08-01

    We studied the effect of host gender and body mass on species richness of flea infracommunities in nine rodent host species from three biomes (temperate zone of central Europe, desert of the Middle East and the tropics of East Africa). Using season- and species-specific generalized linear mixed models and controlling for year-to-year variation, spatial clustering of rodent sampling and over-dispersion of the data, we found inconsistent associations between host characteristics and flea species richness. We found strong support for male-biased flea parasitism, especially during the reproductive period (higher species richness in male hosts than in females) in all considered European rodents (Apodemus agrarius, Myodes glareolus and Microtus arvalis) and in one rodent species from the Middle East (Dipodillus dasyurus). In contrast, two of three African rodent species (Lophuromys kilonzoi and Praomys delectorum) demonstrated a trend of female-biased flea species richness. Positive associations between body mass and the number of flea species were detected mainly in males (five of nine species: A. agrarius, M. glareolus, M. arvalis, D. dasyurus and Mastomys natalensis) and not in females (except for M. natalensis). The results of this study support earlier reports that gender-biased, in general, and male-biased, in particular, infestation by ectoparasites is not a universal rule. This suggests that mechanisms of parasite acquisition by an individual host are species-specific and have evolved independently in different rodent host-flea systems.

  14. A comparison of bats and rodents as reservoirs of zoonotic viruses: are bats special?

    PubMed Central

    Luis, Angela D.; Hayman, David T. S.; O'Shea, Thomas J.; Cryan, Paul M.; Gilbert, Amy T.; Pulliam, Juliet R. C.; Mills, James N.; Timonin, Mary E.; Willis, Craig K. R.; Cunningham, Andrew A.; Fooks, Anthony R.; Rupprecht, Charles E.; Wood, James L. N.; Webb, Colleen T.

    2013-01-01

    Bats are the natural reservoirs of a number of high-impact viral zoonoses. We present a quantitative analysis to address the hypothesis that bats are unique in their propensity to host zoonotic viruses based on a comparison with rodents, another important host order. We found that bats indeed host more zoonotic viruses per species than rodents, and we identified life-history and ecological factors that promote zoonotic viral richness. More zoonotic viruses are hosted by species whose distributions overlap with a greater number of other species in the same taxonomic order (sympatry). Specifically in bats, there was evidence for increased zoonotic viral richness in species with smaller litters (one young), greater longevity and more litters per year. Furthermore, our results point to a new hypothesis to explain in part why bats host more zoonotic viruses per species: the stronger effect of sympatry in bats and more viruses shared between bat species suggests that interspecific transmission is more prevalent among bats than among rodents. Although bats host more zoonotic viruses per species, the total number of zoonotic viruses identified in bats (61) was lower than in rodents (68), a result of there being approximately twice the number of rodent species as bat species. Therefore, rodents should still be a serious concern as reservoirs of emerging viruses. These findings shed light on disease emergence and perpetuation mechanisms and may help lead to a predictive framework for identifying future emerging infectious virus reservoirs. PMID:23378666

  15. The role of rodents in the ecology of Ixodes ricinus and associated pathogens in Central and Eastern Europe.

    PubMed

    Mihalca, Andrei D; Sándor, Attila D

    2013-01-01

    Rodents comprise more species than any other mammal order. Most rodents are considered keystone species in their ecological communities, hence the survival of many other species in the ecosystem depend on them. From medical point of view, this is particularly important for rodent-dependent pathogens. In the particular case of tick-borne diseases, rodents are important as hosts for vector ticks and as reservoir hosts (Lyme borreliosis, human granulocytic anaplasmosis, Crimean-Congo hemorrhagic fever, Tick-borne relapsing fevers, tick-borne rickettsioses, babesiosis). Community and population ecology of rodents was shown to be correlated with disease ecology in the case of many tick-borne diseases. In Eastern Europe, several adult hard-tick species use rodents as their principal hosts: Ixodes apronophorus, I. crenulatus, I. laguri, I. redikorzevi, I. trianguliceps. However, the majority of ticks feeding on rodents are immature stages of ticks which as adults are parasitic on larger mammals. Larvae and nymphs of Ixodes ricinus, the most abundant and medically important tick from Europe, are commonly found on rodents. This is particularly important, as many rodents are synanthropic and, together with other micromammals and birds are often the only available natural hosts for ticks in urban environments. This work reviews the correlated ecology of rodents and I. ricinus.

  16. Metformin improves urine concentration in rodents with nephrogenic diabetes insipidus

    PubMed Central

    Efe, Orhan; Klein, Janet D.; LaRocque, Lauren M.; Ren, Huiwen; Sands, Jeff M.

    2016-01-01

    Urine concentration is regulated by vasopressin. Congenital nephrogenic diabetes insipidus (NDI) is caused by vasopressin type 2 receptor (V2R) mutations. We studied whether metformin could improve urine concentration in rodent models of congenital NDI by stimulating AMPK. To block the V2R in rats, tolvaptan (10 mg/kg/d) was given by oral gavage with or without metformin (800 mg/kg/d). Control rats received vehicle with or without metformin. Tamoxifen-induced V2R KO mice were given metformin (600 mg/kg) or vehicle twice daily. Urine osmolality in tolvaptan-treated rats (1,303 ± 126 mOsM) was restored to control levels by metformin (2,335 ± 273 mOsM) within 3 days and was sustained for up to 10 days. Metformin increased protein abundance of inner medullary urea transporter UT-A1 by 61% and aquaporin 2 (AQP2) by 44% in tolvaptan-treated rats, and immunohistochemistry showed increased membrane accumulation of AQP2 with acute and chronic AMPK stimulation. Outer medullary Na+-K+-2Cl– cotransporter 2 (NKCC2) abundance increased (117%) with AMPK stimulation in control rats but not in V2R-blocked rats. Metformin increased V2R KO mouse urine osmolality within 3 hours, and the increase persisted for up to 12 hours. Metformin increased AQP2 in the V2R KO mice similar to the tolvaptan-treated rats. These results indicate that AMPK activators, such as metformin, might provide a promising treatment for congenital NDI. PMID:27478876

  17. NASA Rodent Foodbar: Long Term Effects in Swiss Webster Mice

    NASA Technical Reports Server (NTRS)

    Santiago, D. L.; Yu, D. S.; Naficy, N. H.; Roghani, P. M.; Dalton, B. P.; Barrett, J. E.; Dalton, Bonnie (Technical Monitor)

    2001-01-01

    Swiss Webster male and female mice (150 of each) were fed NASA Rodent Foodbar for more than 110 days to test the diet's nutritional adequacy for use in future long-term studies aboard the International Space Station. Mice were grouped three to a cage (one cage = one sample) and cages were assigned to either Foodbar or Purina Chow #5001 (control) diet groups. Body weights, food intake, and water intake were obtained throughout the study. There were no significant differences in body weights between male Foodbar fed and Chow fed males (p=0.58), and at 15 weeks into the female mouse study there appear to be no significant body weight differences. Both male and female Foodbar fed groups consumed more food and less water than their Chow controls, both factors thought to be attributable to the high moisture content of the Foodbars (26% versus 10% for Chow). All differences in gross food and water consumption had p-values of less than 0.01. When food and water intake were adjusted for the moisture content in the food, both male and female Foodbar fed animals consumed less food, but still had a lower water intake rate than their controls. (p is less than 0.01). Preliminary analysis on blood samples from male and female halfway point dissections suggests differences in glucose and fat metabolism. In both male and female Foodbar fed animals, blood glucose values were significantly lower (p is less than 0.01) but there were no significant differences in cholesterol levels (p=0.51). In Foodbar fed females, triglycerides were significantly higher (p is less than 0.01). These data suggest that Foodbars allow for normal growth in Swiss Webster mice, but affect some blood chemistry parameters.

  18. Rodent neurotoxicity bioassays for screening contaminated Great Lakes fish

    SciTech Connect

    Beattie, M.K.; Hoffman, R.; Gerstenberger, S.; Dellinger, J.A.

    1996-03-01

    Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine were administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavior data collected prior to exposure, and on days 7, 14, 55 {+-} 2, 85 {+-} 2. Motor activity data were collected on days 30 {+-} 2, 60 {+-} 2, and 90 {+-} 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavior responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavior alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.

  19. Expensive Brains: “Brainy” Rodents have Higher Metabolic Rate

    PubMed Central

    Sobrero, Raúl; May-Collado, Laura J.; Agnarsson, Ingi; Hernández, Cristián E.

    2011-01-01

    Brains are the centers of the nervous system of animals, controlling the organ systems of the body and coordinating responses to changes in the ecological and social environment. The evolution of traits that correlate with cognitive ability, such as relative brain size is thus of broad interest. Brain mass relative to body mass (BM) varies among mammals, and diverse factors have been proposed to explain this variation. A recent study provided evidence that energetics play an important role in brain evolution (Isler and van Schaik, 2006). Using composite phylogenies and data drawn from multiple sources, these authors showed that basal metabolic rate (BMR) correlates with brain mass across mammals. However, no such relationship was found within rodents. Here we re-examined the relationship between BMR and brain mass within Rodentia using a novel species-level phylogeny. Our results are sensitive to parameter evaluation; in particular how species mass is estimated. We detect no pattern when applying an approach used by previous studies, where each species BM is represented by two different numbers, one being the individual that happened to be used for BMR estimates of that species. However, this approach may compromise the analysis. When using a single value of BM for each species, whether representing a single individual, or available species mean, our findings provide evidence that brain mass (independent of BM) and BMR are correlated. These findings are thus consistent with the hypothesis that large brains evolve when the payoff for increased brain mass is greater than the energetic cost they incur. PMID:21811456

  20. Memory deficits associated with khat (Catha edulis) use in rodents.

    PubMed

    Kimani, S T; Patel, N B; Kioy, P G

    2016-02-01

    Khat products and chewing practices are common in East Africa, Middle East for centuries with concomitant socio-economic and public health repercussions. We assessed memory deficits associated with khat use in rodents. Young male CBA mice, 5-7 weeks old (n = 20), weighing 25-35 g were used. Mice were treated with either 40, 120 or 360 mg/kg body weight (bw) methanolic khat extract, or 0.5 ml saline for 10 days. Spatial acquisition, reversal and reference memory were assessed using modified Morris Water maze (MMWM). Mice treated with 40 mg/kg khat extract had longer (t4 = 4.12 p = 0.015) and t4 = 2.28 p = 0.065) escape latency on first and second day during reversal relative to the baseline. Under 120 mg/kg khat dose, the escape latency was shorter (t4 = -2.49 p = 0.05) vs (t3 = -2.5 p = 0.05) on third and fourth day. Further, treatment with 360 mg/kg khat extract resulted in significantly longer time (49.13, 33.5, 40.2 and 35.75) vs. (23.5 s), compared to baseline. Mice treated with khat or control preferred the target quadrant post acquisition while differential pattern was seen during reversal phase. Mice treated with 40 or 120 mg/kg khat showed significant preference for target quadrant. Substantial time (19.9) was spent in the old target compared to the new (16.9 s) by animals treated with highest dose however, the difference was not significant. There is a biological plausibility that chronic khat use may induce memory deficits and impair cognitive flexibility. The differential patterns of memory deficits may reflect the differences in dose effect as well as time dependent impairment.

  1. Effects of stress on behavioral flexibility in rodents.

    PubMed

    Hurtubise, Jessica L; Howland, John G

    2017-03-14

    Cognitive flexibility is the ability to switch between different rules or concepts and behavioral flexibility is the overt physical manifestation of these shifts. Behavioral flexibility is essential for adaptive responses and commonly measured by reversal learning and set-shifting performance in rodents. Both tasks have demonstrated vulnerability to stress with effects dependent upon stressor type and number of repetitions. This review compares the effects of stress on reversal learning and set-shifting to provide insight into the differential effect of stress on cognition. Acute and short-term repetition of stress appears to facilitate reversal learning whereas the longer term repetition of stress impairs reversal learning. Stress facilitated intradimensional set-shifting within a single, short-term stress protocol but otherwise generally impaired set-shifting performance in acute and repeated stress paradigms. Chronic unpredictable stress impairs reversal learning and set-shifting whereas repeated cold intermittent stress selectively impairs reversal learning and has no effect on set-shifting. In considering the mechanisms underlying the effects of stress on behavioral flexibility, pharmacological manipulations performed in conjunction with stress are also reviewed. Blocking corticosterone receptors does not affect the facilitation of reversal learning following acute stress but the prevention of corticosterone synthesis rescues repeated stress-induced set-shifting impairment. Enhancing post-synaptic norepinephrine function, serotonin availability, and dopamine receptor activation rescues and/or prevents behavioral flexibility performance following stress. While this review highlights a lack of a standardization of stress paradigms, some consistent effects are apparent. Future studies are necessary to specify the mechanisms underlying the stress-induced impairments of behavioral flexibility, which will aid in alleviating these symptoms in patients with some

  2. (-)-α-Bisabolol reduces orofacial nociceptive behavior in rodents.

    PubMed

    Melo, Luana Torres; Duailibe, Mariana Araújo Braz; Pessoa, Luciana Moura; da Costa, Flávio Nogueira; Vieira-Neto, Antonio Eufrásio; de Vasconcellos Abdon, Ana Paula; Campos, Adriana Rolim

    2017-02-01

    The purposes of this study were to evaluate the anti-nociceptive effect of oral and topical administration of (-)-α-bisabolol (BISA) in rodent models of formalin- or cinnamaldehyde-induced orofacial pain and to explore the inhibitory mechanisms involved. Orofacial pain was induced by injecting 1.5% formalin into the upper lip of mice (20 μL) or into the temporomandibular joint (TMJ) of rats (50 μL). In another experiment, orofacial pain was induced with cinnamaldehyde (13.2 μg/lip). Nociceptive behavior was proxied by time (s) spent rubbing the injected area and by the incidence of head flinching. BISA (100, 200, or 400 mg/kg p.o. or 50, 100, or 200 mg/mL topical) or vehicle was administered 60 min before pain induction. The two formulations (lotion and syrup) were compared with regard to efficacy. The effect of BISA remained after incorporation into the formulations, and nociceptive behavior decreased significantly in all tests. The high binding affinity observed for BISA and TRPA1 in the molecular docking study was supported by in vivo experiments in which HC-030031 (a TRPA1 receptor antagonist) attenuated pain in a manner qualitatively and quantitatively similar to that of BISA. Blockers of opioid receptors, NO synthesis, and K(+) ATP channels did not affect orofacial pain, nor inhibit the effect of BISA. In conclusion, BISA had a significant anti-nociceptive effect on orofacial pain. The effect may in part be due to TRPA1 antagonism. The fact that the effect of BISA remained after incorporation into oral and topical formulations suggests that the compound may be a useful adjuvant in the treatment of orofacial pain.

  3. Brain Maturation in Neonatal Rodents is Impeded by Sevoflurane Anesthesia

    PubMed Central

    Makaryus, Rany; Lee, Hedok; Feng, Tian; Park, June-Hee; Nedergaard, Maiken; Jacob, Zvi; Enikolopov, Grigori; Benveniste, Helene

    2015-01-01

    Background A wealth of data shows neuronal demise after general anesthesia in the very young rodent brain. Here we apply proton magnetic resonance spectroscopy (1HMRS), testing the hypothesis that neurotoxic exposure during peak synaptogenesis can be tracked via changes in neuronal metabolites. Methods 1HMRS spectra was acquired in the brain (thalamus) of neonatal rat pups 24- and 48 h after sevoflurane exposure on post-natal day (PND) 7 and 15, and in unexposed, sham controls. A repeated measure ANOVA was performed to examine if changes in metabolites were different between exposed and unexposed groups. Sevoflurane-induced neurotoxicity on PND7 was confirmed by immunohistochemistry. Results In unexposed PND7 pups (N=21), concentration of NAA ([NAA]) increased by 16% from PND8 to PND9, whereas in exposed PND7 pups (N=19), [NAA] did not change and concentration of choline compounds ([GPC+PCh]) decreased by 25%. In PND15 rats, [NAA] increased from PND16 to PND17 for both the exposed (N=14) and unexposed (N=16) groups. Two-way ANOVA for PND7 pups demonstrated changes over time observed in [NAA] (p=0.031) and [GPC+PCh] (p=0.024) were different between those two groups. Conclusions We demonstrated that normal [NAA] increase from PND8 to PND9 was impeded in sevoflurane-exposed rats when exposed at PND7; however, not impeded when exposed on PND15. Furthermore, we showed that non-invasive 1HMRS is sufficiently sensitive to detect subtle differences in developmental time trajectory of [NAA]. This is potentially clinically relevant since 1HMRS can be applied across species, and may be useful in providing evidence of neurotoxicity in the human neonatal brain. PMID:26181336

  4. Determinants of iodothyronine deiodinase activities in rodent uterus.

    PubMed

    Wasco, Emily C; Martinez, Elena; Grant, Katherine S; St Germain, Emily A; St Germain, Donald L; Galton, Valerie Anne

    2003-10-01

    The deiodinase types 2 and 3 (D2, D3), which convert T4 to active and inactive metabolites, respectively, are expressed in the rodent uterus and highly induced during pregnancy. To examine the factors regulating the expression of these enzymes in this tissue, we studied D2 and D3 activity in pregnant rats, in pseudopregnant rats before and after the induction of artificial decidualization, and in ovariectomized rats treated with 17beta-estradiol (E2) and/or progesterone (P). Our results demonstrate that induction of D3 activity begins immediately after implantation and increases markedly over the next 72 h. A similar time course and magnitude of D3 induction is noted in the artificially decidualized uterus in pseudopregnant rats, whereas only minimal increases in activity are observed in the nondecidualized control uterine horns in the same animal. In contrast, D2 activity is not induced by a decidualization stimulus. In spontaneously cycling female rats, both D2 and D3 were observed to be 3- to 8-fold higher in proestrus, compared with diestrus. Furthermore, levels of D2 and D3 activity were greatly increased in ovariectomized rats given E2 and P in various combinations. D2 activity was stimulated primarily by E2, whereas E2 and P acted synergistically to increase D3 activity. These results demonstrate that E2 and P regulate thyroid hormone metabolism in the uterus, and that the implantation process is a potent stimulus for the induction of D3 activity in this organ. Such precise and profound changes in deiodinase expression are likely to play important physiological roles in fetal development and may influence uterine function.

  5. Lung imaging in rodents using dual energy micro-CT

    NASA Astrophysics Data System (ADS)

    Badea, C. T.; Guo, X.; Clark, D.; Johnston, S. M.; Marshall, C.; Piantadosi, C.

    2012-03-01

    Dual energy CT imaging is expected to play a major role in the diagnostic arena as it provides material decomposition on an elemental basis. The purpose of this work is to investigate the use of dual energy micro-CT for the estimation of vascular, tissue, and air fractions in rodent lungs using a post-reconstruction three-material decomposition method. We have tested our method using both simulations and experimental work. Using simulations, we have estimated the accuracy limits of the decomposition for realistic micro-CT noise levels. Next, we performed experiments involving ex vivo lung imaging in which intact lungs were carefully removed from the thorax, were injected with an iodine-based contrast agent and inflated with air at different volume levels. Finally, we performed in vivo imaging studies in (n=5) C57BL/6 mice using fast prospective respiratory gating in endinspiration and end-expiration for three different levels of positive end-expiratory pressure (PEEP). Prior to imaging, mice were injected with a liposomal blood pool contrast agent. The mean accuracy values were for Air (95.5%), Blood (96%), and Tissue (92.4%). The absolute accuracy in determining all fraction materials was 94.6%. The minimum difference that we could detect in material fractions was 15%. As expected, an increase in PEEP levels for the living mouse resulted in statistically significant increases in air fractions at end-expiration, but no significant changes in end-inspiration. Our method has applicability in preclinical pulmonary studies where various physiological changes can occur as a result of genetic changes, lung disease, or drug effects.

  6. Gold nanoparticle aerosols for rodent inhalation and translocation studies

    NASA Astrophysics Data System (ADS)

    Möller, Winfried; Gibson, Neil; Geiser, Marianne; Pokhrel, Suman; Wenk, Alexander; Takenaka, Shinji; Schmid, Otmar; Bulgheroni, Antonio; Simonelli, Federica; Kozempel, Jan; Holzwarth, Uwe; Wigge, Christoph; Eigeldinger-Berthou, Sylvie; Mädler, Lutz; Kreyling, Wolfgang G.

    2013-04-01

    The intensive use of nano-sized particles in many different applications necessitates studies on their risk assessment as there are still open questions on their safe handling and utilization. For reliable risk assessment, the interaction of nanoparticles (NP) with biological systems after various routes of exposure needs to be investigated using well-characterized NP. We report here on the generation of gold-NP (Au-NP) aerosols for inhalation studies with the spark ignition technique, and their characterization in terms of chemical composition, physical structure, morphology, and specific surface area, and on interaction with lung tissues and lung cells after 1 h inhalation by mice. The originally generated agglomerated Au-NP were converted into compact spherical Au-NP by thermal annealing at 600 °C, providing particles of similar mass, but different size and specific surface area. Since there are currently no translocation data available on inhaled Au-NP in the 10-50 nm diameter range, the emphasis was to generate NP as small as 20 nm for inhalation in rodents. For anticipated in vivo systemic translocation and dosimetry analyses, radiolabeled Au-NP were created by proton irradiating the gold electrodes of the spark generator, thus forming gamma ray emitting 195Au with 186 days half-life, allowing long-term biokinetic studies. The dissolution rate of 195Au from the NP was below detection limits. The highly concentrated, polydisperse Au-NP aerosol (1-2 × 107 NP/cm3) proved to be constant over several hours in terms of its count median mobility diameter, its geometric standard deviation and number concentration. After collection on filters particles can be re-suspended and used for instillation or ingestion studies.

  7. Sperm Competition, Sperm Numbers and Sperm Quality in Muroid Rodents

    PubMed Central

    Gómez Montoto, Laura; Magaña, Concepción; Tourmente, Maximiliano; Martín-Coello, Juan; Crespo, Cristina; Luque-Larena, Juan José

    2011-01-01

    Sperm competition favors increases in relative testes mass and production efficiency, and changes in sperm phenotype that result in faster swimming speeds. However, little is known about its effects on traits that contribute to determine the quality of a whole ejaculate (i.e., proportion of motile, viable, morphologically normal and acrosome intact sperm) and that are key determinants of fertilization success. Two competing hypotheses lead to alternative predictions: (a) sperm quantity and quality traits co-evolve under sperm competition because they play complementary roles in determining ejaculate's competitive ability, or (b) energetic constraints force trade-offs between traits depending on their relevance in providing a competitive advantage. We examined relationships between sperm competition levels, sperm quantity, and traits that determine ejaculate quality, in a comparative study of 18 rodent species using phylogenetically controlled analyses. Total sperm numbers were positively correlated to proportions of normal sperm, acrosome integrity and motile sperm; the latter three were also significantly related among themselves, suggesting no trade-offs between traits. In addition, testes mass corrected for body mass (i.e., relative testes mass), showed a strong association with sperm numbers, and positive significant associations with all sperm traits that determine ejaculate quality with the exception of live sperm. An “overall sperm quality” parameter obtained by principal component analysis (which explained 85% of the variance) was more strongly associated with relative testes mass than any individual quality trait. Overall sperm quality was as strongly associated with relative testes mass as sperm numbers. Thus, sperm quality traits improve under sperm competition in an integrated manner suggesting that a combination of all traits is what makes ejaculates more competitive. In evolutionary terms this implies that a complex network of genetic and

  8. Stress induced obesity: lessons from rodent models of stress

    PubMed Central

    Patterson, Zachary R.; Abizaid, Alfonso

    2013-01-01

    Stress was once defined as the non-specific result of the body to any demand or challenge to homeostasis. A more current view of stress is the behavioral and physiological responses generated in the face of, or in anticipation of, a perceived threat. The stress response involves activation of the sympathetic nervous system and recruitment of the hypothalamic-pituitary-adrenal (HPA) axis. When an organism encounters a stressor (social, physical, etc.), these endogenous stress systems are stimulated in order to generate a fight-or-flight response, and manage the stressful situation. As such, an organism is forced to liberate energy resources in attempt to meet the energetic demands posed by the stressor. A change in the energy homeostatic balance is thus required to exploit an appropriate resource and deliver useable energy to the target muscles and tissues involved in the stress response. Acutely, this change in energy homeostasis and the liberation of energy is considered advantageous, as it is required for the survival of the organism. However, when an organism is subjected to a prolonged stressor, as is the case during chronic stress, a continuous irregularity in energy homeostasis is considered detrimental and may lead to the development of metabolic disturbances such as cardiovascular disease, type II diabetes mellitus and obesity. This concept has been studied extensively using animal models, and the neurobiological underpinnings of stress induced metabolic disorders are beginning to surface. However, different animal models of stress continue to produce divergent metabolic phenotypes wherein some animals become anorexic and lose body mass while others increase food intake and body mass and become vulnerable to the development of metabolic disturbances. It remains unclear exactly what factors associated with stress models can be used to predict the metabolic outcome of the organism. This review will explore a variety of rodent stress models and discuss the

  9. Complementarity of genotoxic and nongenotoxic predictors of rodent carcinogenicity.

    PubMed

    Kitchin, K T; Brown, J L; Kulkarni, A P

    1994-01-01

    Twenty-one chemicals carcinogenic in rodent bioassays were selected for study. The chemicals were administered by gavage in two dose levels to female Sprague-Dawley rats. The effects of these 21 chemicals on four biochemical assays [hepatic DNA damage by alkaline elution (DD), hepatic ornithine decarboxylase activity (ODC), serum alanine aminotransferase activity (ALT), and hepatic cytochrome P-450 content (P450)] were determined. Available data from seven cancer predictors published by others [the Ames test (AMES), mutation in Salmonella typhimurium TA 1537 (TA 1537), structural alerts (SA), mutation in mouse lymphoma cells (MOLY), chromosomal aberrations in Chinese hamster ovary cells (ABS), sister chromatid exchange in hamster ovary cells (SCE), and the ke test (ke)] were also compiled for these 21 chemical carcinogens plus 28 carcinogens and 62 noncarcinogens already published by our laboratory. From the resulting 111 (chemicals) by 11 (individual cancer predictors) data matrix, the five operational characteristics (sensitivity, specificity, positive predictivity, negative predictivity, and concordance) of each of the 11 individual cancer predictors (four biochemical parameters of this study and seven cancer predictors of others) are presented. Two examples of complementarity or synergy of composite cancer predictors were found. To obtain maximum concordance it was necessary to combine both genotoxic and nongenotoxic cancer predictors. The composite cancer predictor (DD or [ODC and P450] or [ODC and ALT]) had higher concordance than did any of the four individual cancer predictors from which it was constructed. Similarly, the composite cancer predictor (TA 1537 or DD or [ODC and P450] or [ODC and ALT]) had higher concordance than any of its five individual constituent cancer predictors. Complementarity or synergy has been demonstrated both 1) among genotoxic cancer predictors (DD and TA 1537) and 2) between nongenotoxic (ODC, P450, and ALT) and genotoxic cancer

  10. The diversity of microparasites of rodents: a comparative analysis that helps in identifying rodent-borne rich habitats in Southeast Asia

    PubMed Central

    Bordes, Frédéric; Herbreteau, Vincent; Dupuy, Stéphane; Chaval, Yannick; Tran, Annelise; Morand, Serge

    2013-01-01

    Background Predicting habitats prone to favor disease transmission is challenging due to confounding information on habitats, reservoirs, and diseases. Comparative analysis, which aims at investigating ecological and evolutionary patterns among species, is a tool that may help. The emergence of zoonotic pathogens is a major health concern and is closely linked to habitat modifications by human activities. Risk assessment requires a better knowledge of the interactions between hosts, parasites, and the landscape. Methods We used information from a field spatial study that investigated the distribution of murid rodents, in various habitats of three countries in Southeast Asia, in combination with their status of infection by 10 taxa of microparasites obtained from the literature. Microparasite species richness was calculated by rodent species on 20,272 rodents of 13 species. Regression tree models and generalized linear models were used to explain microparasite diversity by the average distance between the trapping site and five categories of land cover: forest, steep agriculture land, flat agriculture land, water, and built-up surfaces. Another variable taken into account was the slope. Results We found that microparasite diversity was positively associated with flat agriculture land, in this context mainly rice fields, and negatively associated with slope. Microparasite diversity decreased sharply a 100 m or less from flat agriculture land. Conclusion We conclude that there is high microparasite circulation in rodents of flooded farmlands, meaning possibly a higher risk of disease for human inhabitants. PMID:23577229

  11. Investigation and characterization of the frozen feeder rodent industry in Texas following a multi-state Salmonella typhimurium outbreak associated with frozen vacuum-packed rodents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A Salmonella outbreak investigation identified a frozen feeder rodent facility (Supplier A) served as the vector of a pathogenic Salmonella strain for pet snakes and humans. From Supplier A, seven Salmonella positive samples out of 45 environmental swabs were found, and only one adult mouse out of ...

  12. Rough-Legged Buzzards, Arctic Foxes and Red Foxes in a Tundra Ecosystem without Rodents

    PubMed Central

    Pokrovsky, Ivan; Ehrich, Dorothée; Ims, Rolf A.; Kondratyev, Alexander V.; Kruckenberg, Helmut; Kulikova, Olga; Mihnevich, Julia; Pokrovskaya, Liya; Shienok, Alexander

    2015-01-01

    Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species—rough-legged buzzard, arctic fox and red fox – perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey – altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period – a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers. PMID:25692786

  13. Modeling susceptible infective recovered dynamics and plague persistence in California rodent-flea communities.

    PubMed

    Foley, Patrick; Foley, Janet

    2010-01-01

    Plague persists as an enzootic in several very different rodent-flea communities around the world. In California, a diversity of rodent-flea communities maintains the disease, and a single-host reservoir seems unlikely. Logistic regression of plague presence on climate and topographic variables predicts plague in many localities where it is absent. Thus, a dynamic community-based analysis was needed. Deterministic Susceptible Infective Recovered (SIR) models were adapted for plague and analyzed with an eye for insights concerning disease persistence. An R simulation program, Plaguesirs, was developed incorporating multihost and multivector SIR dynamics, demographic and environmental stochasticity, density dependence, and seasonal variation in birth and death. Flea-rodent utilization matrices allowed us to get transmission rates as well as flea carrying capacities. Rodent densities allowed us to estimate host carrying capacities, while maximum birth rates were mainly approximated through an examination of litter phenology and demography. We ran a set of simulations to assess the role of community structure in maintaining plague in a simulated version of Chuchupate campground in Ventura County. Although the actual campground comprises 10 rodent and 19 flea species, we focused on a subset suspected to act as a reservoir community. This included the vole Microtus californicus, the deer mouse Peromyscus maniculatus, the Ceratophyllid fleas Aetheca wagneri and Malareus telchinum, and the Leptopsyllid flea Peromyscopsylla hesperomys. The dynamics of 21 subsets of this community were simulated for 20 years. Single-rodent communities showed much lower disease persistence than two-rodent communities. However, so long as Malareus was present, endemicity was enhanced; removal of the other two fleas slightly increas