Name: measuring the strength of mice
Uploaded: 2013-06-02T14:00:00.000+00:00
Duration: 6 min 17 s
Description: Watch this Scientific Journal Video about Measuring the Strength of Mice at JoVE.com

Le Wellcome Trust pour fournir du financement du libre accès à l&#39;Université d&#39;Oxford. Robert Deacon est un membre du groupe OXION Oxford, financée par Wellcome Trust subvention WT084655MA.

1. Appareil Test de l&#39;écran inversé de 1,1 Kondziela L&#39;écran inversé est un 43 cm carré de treillis métallique composé de 12 carrés de 1 mm fil mm de diamètre (figure 1). Il est entouré d&#39;un cm de perles en bois de profondeur 4 (qui empêche la souris occasionnelle qui tente de partir grimper sur l&#39;autre côté) (Figure 2). 1.2 essai de musculation Sept poids constituent l&#39;appareil. Chacun se compose d&#39;une boule de fil emmêlé fine jauge en acier inoxydable, un «collecteur échelle&quot; tel qu&#39;il est utilisé pour prévenir la formation de calcaire dans les bouilloires échelle nationale. Le poids de ce est faible (7 g), mais chaque collecteur échelle est attachée à une série de maillons en acier, pesant chacun environ 13 g. Le nombre de liaisons varie de un à sept. Leurs poids sont donc: 20, 33, 46, 59, 72, 85 et 98 g (figures 3 et 4). 2. Proprocédure Pour tous les tests, mettre les souris à la salle expérimentale 5-20 min avant de le tester pour s&#39;assurer qu&#39;ils sont correctement éveillé. En règle générale, pour permettre la récupération de la force musculaire et un retour à des niveaux normaux d&#39;éveil, reposer les souris par un retour à la cage à la maison après chaque essai moteur. <ol><li> Test de l&#39;écran inversé de Kondziela </li><li> Procédure: Placez la souris au centre de l&#39;écran en treillis, démarrer un chronomètre, faire pivoter l&#39;écran pour une position inversée plus de 2 sec, avec la tête de la souris déclin première. Maintenez l&#39;écran de façon constante 40-50 cm au-dessus d&#39;une surface matelassée. Noter le temps quand la souris tombe, ou de le supprimer lorsque l&#39;heure de critère de 60 secondes est atteint. Temps de critère plus long peut être utile pour certaines expériences. </li><li> Marquant l&#39;écran inversé: </li></ol> Se situant entre 1-10 sec = 1 Se situant entre 11-25 sec = 2 Se situant entre 26-60 sec = 3 Chute après 60 sec = 4 Ou, par exemple pendant 2 min: Se situant entre 1-10 sec = 1 Se situant entre 11-25 sec = 2 Se situant entre 26-60 sec = 3 Se situant entre 61-90 sec = 4 Chute après 90 sec = 5 3. Poids essai Maintenez la souris par la base de milieu / de la queue et l&#39;abaisser pour lui permettre de saisir le premier poids (20 g) qui est couché sur le banc de laboratoire. Comme il saisit le collecteur d&#39;échelle de fil avec ses pattes de devant, commencer une horloge d&#39;arrêt et augmenter la souris jusqu&#39;à ce que le lien est évident du banc. Une attente de trois secondes est le critère. Si la souris tombe le poids en moins de 3 secondes, noter le temps qu&#39;il a occupé le poids. Reste la souris pendant environ 10 secondes et l&#39;essayer sur le poids une fois de plus. Si elle échoue trois fois, qui met fin au procès, et la souris se voit attribuer le temps / poids atteint au maximum. Si elle maintient pendant 3 secondes puis essayer sur le prochain poids lourd. Si elle soulève ce pendant 3 secondes, le tester sur le prochain poids lourd, après que vous ayeztesté tous ses compagnons de cage sur le premier poids. Encore une fois, on lui donne trois chances pour supporter le poids de 3 sec. Un score total final est calculé comme le produit du nombre de maillons de la chaîne lourde qui s&#39;est tenue pour la pleine 3 sec, multiplié par le temps (sec) il est détenu. Si le poids le plus lourd est tombé avant 3 secondes une valeur intermédiaire approprié est calculé. Ainsi, une souris tenant un poids de 5 lien pendant 3 secondes, mais incapable de soulever un poids de 6-link, se voit attribuer un score de (5 x 3) = 15. Si elle maintient le poids 6-link pendant 1 seconde, elle marque (5 x 3) + (1) = 16. Parfois, les souris peuvent ne pas être suffisamment motivés pour saisir l&#39;appareil. Cela se produit généralement chez les animaux âgés. Ce problème peut être minimisé par la détention des souris par la queue pendant une longue période avant de le mettre à distance de préhension de la boule de fil.

<ol>
	<li>Bulfield, G., Siller, W. G., Wight, P. A., Moore, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=K.J.X+chromosome-linked+muscular+dystrophy+(mdx)+in+the+mouse.">K.J.X chromosome-linked muscular dystrophy (mdx) in the mouse.</a> Proc. Natl. Acad. Sci. U.S.A. 81, 1189-1192 (1984).</li><li>Contet, C., Rawlins, J. N. P., Deacon, R. M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+129S2/SvHsd+and+C57BL/6JOlaHsd+mice+on+a+test+battery+assessing+sensorimotor,+affective+and+cognitive+behaviours:+implications+for+the+study+of+genetically+modified+mice.">A comparison of 129S2/SvHsd and C57BL/6JOlaHsd mice on a test battery assessing sensorimotor, affective and cognitive behaviours: implications for the study of genetically modified mice.</a> Behavioural Brain Research. 124, 33-46 (2001).</li><li>Deacon, R. M. J., Brook, R. C., Meyer, D., Haeckel, O., Ashcroft, F. M., Miki, T., Seino, S., Liss, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Behavioral+phenotyping+of+mice+lacking+the+KATP+channel+subunit+Kir6.2.">Behavioral phenotyping of mice lacking the KATP channel subunit Kir6.2.</a> Physiol. Behav. 87, 723-733 (2006).</li><li>Deacon, R. M. J., Croucher, A., Rawlins, J. N. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hippocampal+cytotoxic+lesion+effects+on+species-typical+behaviors+in+mice.">Hippocampal cytotoxic lesion effects on species-typical behaviors in mice.</a> Behav. Brain Res. 132, 203-213 (2002).</li><li>Rawlins, J. N. P., Morley, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+the+behavior+of+C57BL/6+and+C57BL/10+mice.">A comparison of the behavior of C57BL/6 and C57BL/10 mice.</a> Behav. Brain Res. 179, 239-247 (2007).</li><li>Guenther, K., Deacon, R. M. J., Perry, V. H., Rawlins, J. N. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+behavioural+changes+in+scrapie-affected+mice+and+the+influence+of+dapsone.">Early behavioural changes in scrapie-affected mice and the influence of dapsone.</a> Eur. J. Neurosci. 14, 401-409 (2001).</li><li>Kondziela, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eine+neue+method+zur+messung+der+muskularen+relaxation+bei+weissen+mausen.">Eine neue method zur messung der muskularen relaxation bei weissen mausen.</a> Arch. Int. Pharmacodyn. 152, 277-284 (1964).</li></ol>

Aucun conflit d&#39;intérêt déclaré.

Des modèles murins des nombreuses maladies qui affectent les systèmes de motricité humaine sont en développement constant, donc de bons tests de résistance chez la souris sont indispensables. Les exemples incluent les nombreuses formes de dystrophie musculaire, la maladie de Parkinson et la chorée de Huntington. tests de résistance trouvent également une utilisation dans des modèles de régénération des nerfs après une lésion du nerf spinal ou périphérique. Accidents de la route industrielle et continuent de causer une invalidité considérable pour les humains, mais beaucoup de travail préclinique étudie actuellement les voies possibles de traitement fondées sur des facteurs de croissance nerveux. Muscles jamais travailler individuellement. Ils sont activés par le cerveau, local ou réflexes spinaux élevés, via les jonctions neuromusculaires et de travailler dans les contraintes des autres muscles et le système squelettique. Par conséquent, la complexité du système signifie que les essais in vivo de la force musculaire chez l&#39;animal éveillé sont essentielles à l&#39;évaluation de son état ​​actuel et l&#39;effects de tous les traitements présumés. De tenir la souris instinctivement à des matériaux ayant une forte emprise, musculus Mus donc un modèle animal idéal pour évaluer les troubles de la force musculaire et les traitements possibles.

Pour un profane, l&#39;idée de mesurer la force chez les souris pourrait sembler absurde, même quelque chose d&#39;un oxymore. Cependant, ce n&#39;est pas sans raison que les souris maison / laboratoire sont nommés Mus musculus. Ils ont fait une très haute résistance / poids, supérieure à celle des rats. Par exemple, des souris adultes peuvent facilement supporter leur propre poids de corps, même en utilisant uniquement l&#39;avant ou pattes postérieures; très peu de rats de laboratoire adultes peuvent le faire. Souris jouent un rôle toujours plus important dans la recherche biomédicale. Ils peuvent être utilisés pour modéliser de nombreux troubles de motricité humaine, à la fois somatiques et le système nerveux central d&#39;origine. Les premiers concernent les plus de trente formes de dystrophie musculaire héréditaire 1 et la myasthénie grave, tandis que des exemples de ces derniers sont la sclérose en plaques, l&#39;atrophie musculaire spinale, la maladie de Parkinson, la maladie de Huntington et la sclérose latérale amyotrophique. Pour tous ces modèles, une évaluation complète de leurs déficits moteurs doit inclure des tests spécifiquesde force.

measuring the strength of mice

Kondziela 7 a conçu le test de l&#39;écran inversé et publié en 1964. C&#39;est un test de force musculaire en utilisant les quatre membres. La plupart des souris normales obtiennent facilement au maximum sur cette tâche, c&#39;est un écran brute rapide mais insensible, et le test des poids décrit dans cet article va fournir une mesure plus fine de la force musculaire. Il ya aussi plusieurs morceaux jauge basées sur la souche d&#39;appareils disponibles dans le commerce qui fourniront des données plus classés que le test de l&#39;écran inversé, mais leur coût peut les mettre hors de portée de nombreux laboratoires qui ne sont pas spécialisés dans les tests de résistance. Ainsi, en 2000, un appareil simple et pas cher a été conçu par l&#39;auteur. Il se compose d&#39;une série de maillons de la chaîne de longueur croissante, attachés à un &quot;collecteur de fourrure&quot; une boule de grillage à mailles fines vendu pour prévenir le tartre s&#39;accumule dans les zones d&#39;eau dure. Une observation accidentelle a révélé que les souris pouvaient saisir ces très serré, donc ils s&#39;est avéré idéal comme un poin de préhensiont pour un appareil de musculation. Un défaut commun avec des compteurs de puissance commerciale, c&#39;est que le bar ou autre caractéristique d&#39;adhérence n&#39;est pas assez fine pour les souris d&#39;exercer une adhérence maximale. En règle générale, plus le fil ou barre, mieux qu&#39;une souris peut saisir avec ses petites griffes. Ceci est un test pur de la force, même si, comme pour tout test facteurs de motivation pourraient jouer un rôle. L&#39;utilisation de capteurs échelle, cependant, semble minimiser les problèmes de motivation que la motivation semble être très élevé chez les jeunes souris adultes normales plus.

Résultats attendus Contet et al. 2 a montré que les souris 129S2/sv une performance similaire au test de poids à des souris C57BL / 6. Femme C57BL / 6 ont obtenu environ 15 129 souris 17, ce qui signifie qu&#39;ils pourraient soulever environ 5 maillons de la chaîne, environ 70 g. Il s&#39;agit d&#39;une grande valeur; normalement 2-3 maillons de la chaîne (score 6-9, 33-46 g) sont levées par C57BL / 6 5. Ces différences sont probablement liées à des facteurs tels que la quantité de manipuler les souris ont reçu et les détails de la technique de l&#39;expérimentateur. Lésions hippocampiques n&#39;affectaient pas la force mesurée soit par le test de poids ou de l&#39;écran 4 inversé. Prions (tremblante) souris malades ont été dépréciées sur l&#39;écran inversé de 18 semaines après l&#39;infection 6. Bien que quelque peu altérée sur la barre horizontale et rotarod par rapport à des souris C57BL / 6, C57BL/10 souris ne sont pas amortis sur 5 haltérophilie. Les souris knockout pour til KATP canal sous-unité Kir6.2 n&#39;avait pas de déficience sur l&#39;écran inversé ou des tests d&#39;haltérophilie, bien que les femmes obtiennent de meilleurs résultats que les hommes sur ce dernier 3. C&#39;était inhabituel, normalement les mâles plus lourds présentent une plus grande résistance que les femelles. <img alt="Figure 1" src="/files/ftp_upload/2610/2610fig1.jpg" /> Figure 1. L&#39;écran inversé. <img alt="Figure 2" src="/files/ftp_upload/2610/2610fig2.jpg" /> Figure 2. Fermer la vue d&#39;une souris sur l&#39;écran inversé. <img alt="Figure 3" src="/files/ftp_upload/2610/2610fig3.jpg" /> Figure 3. Poids, allant de 20 g à 98 g. <img alt="Figure 4" src="/files/ftp_upload/2610/2610fig4.jpg" /> <strong&gt; Figure 4. A d&#39;haltérophilie de la souris.

Watch this Scientific Journal Video about Measuring the Strength of Mice at JoVE.com

Measuring the Strength of Mice

Les déficits de la force musculaire se produisent dans de nombreuses conditions cliniques telles que la maladie du motoneurone. L&#39;écran inversé et des tests de musculation décrit ici mesure la force chez les souris presque exclusivement, avec une influence minimale de facteurs tels que la coordination.

Mesure de la Force de souris

Kondziela7 devised the inverted screen test and published it in 1964. It is a test of muscle strength using all four limbs. Most normal mice easily score ...

Universidad San Sebastian

Research

JoVE Journal

Medicine

54.0K vues.  University of Oxford. Les déficits de la force musculaire se produisent dans de nombreuses conditions cliniques telles que la maladie du motoneurone. L'écran inversé et des tests de musculation décrit ici mesure la force chez les souris presque exclusivement, avec une influence minimale de facteurs tels que la coordination.

Vidéo: Measuring the Strength of Mice

Assessing Functional Performance in the Mdx Mouse Model

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential pharmaceutical compounds and gene therapy approaches have progressed into clinical trials. With improvement in muscle function being the most important end point in these trials, a lot of emphasis has been placed on setting up reliable, reproducible, and easy to perform functional tests to pre clinically assess muscle function, strength, condition, and coordination in the mdx mouse model for DMD. Both invasive and noninvasive tests are available. Tests that do not exacerbate the disease can be used to determine the natural history of the disease and the effects of therapeutic interventions (e.g. forelimb grip strength test, two different hanging tests using either a wire or a grid and rotarod running). Alternatively, forced treadmill running can be used to enhance disease progression and/or assess protective effects of therapeutic interventions on disease pathology. We here describe how to perform these most commonly used functional tests in a reliable and reproducible manner. Using these protocols based on standard operating procedures enables comparison of data between different laboratories.

Assessing Functional Performance in the Mdx Mouse Model

The primary outcome measure in clinical trials for neuromuscular disorders is generally improved muscle function. Therefore, assessing the effect of potential therapeutic compounds on muscle performance pre clinically in mouse models is of great importance. We here describe several functional tests to address this.

Évaluation de la performance fonctionnelle dans le<em&gt; MDX</em&gt; Modèle de souris

Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder for which no cure is available. Nevertheless, several potential ...

Recherche

Sciences du comportement

Measuring Motor Coordination in Mice

Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such as emotionality or cognition can be assessed, however, it is vital to determine whether the motor capabilities of e.g. a mutant or lesioned mouse allow such an assessment. Performance on a maze task requiring strength and coordination, such as the Morris water maze, might well be impaired in a mouse by motor, rather than cognitive, impairments, so it is essential to selectively dissect the latter from the former. For example, sensorimotor impairments caused by NMDA antagonists have been shown to impair water maze performance2. 
Motor coordination has traditionally been assessed in mice and rats by the rotarod test, in which the animal is placed on a horizontal rod that rotates about its long axis; the animal must walk forwards to remain upright and not fall off. Both set speed and accelerating versions of the rotarod are available.
The other three tests described in this article (horizontal bar, static rods and parallel bars) all measure coordination on static apparatus. The horizontal bar also requires strength for adequate performance, particularly of the forelimbs as the mouse initially grips the bar just with the front paws. 
Adult rats do not perform well on tests such as the static rods and parallel bars (personal observations); they appear less well coordinated than mice. I have only tested male rats, however, and male mice seem generally less well coordinated than females. Mice appear to have a higher strength:weight ratio than rats; the Latin name, Mus musculus, seems entirely appropriate. The rotarod, the variations of the foot fault test12 or the Catwalk (Noldus)15 apparatus are generally used to assess motor coordination in rats.

Protocols are presented for two established motor coordination tasks, the accelerating rotarod and horizontal bar, also two tests developed in Oxford recently, the static rods and parallel bars. These tests can detect motor impairments potentially of interest in their own right, as well as being possible variables in tests of other areas of behavior.

Mesure de la coordination motrice chez la souris

Mice are increasingly being used in behavioral neuroscience, largely replacing rats as the behaviorist's animal of choice. Before aspects of behavior such ...

Neurosciences

Battery of Behavioral Tests Assessing General Locomotion, Muscular Strength, and Coordination in Mice

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects and outcomes that a particular disease or treatment has on the animal&#39;s wellbeing and health. There are numerous behavioral tests that may be applied. We selected a test for general locomotion, the open field test (OFT); a test for muscular strength, the mesh test (MT); and a test for coordination, the rotarod test (RR). Testing can be accomplished on a weekly or monthly basis. As a test for general locomotion, the OFT works by objectively monitoring movement parameters while the mouse is in an open field apparatus. The field is generally a 2&#39; x 2&#39; box, and the movements are recorded through laser sensing or through video capture. The mouse is placed in the center of the open field and allowed to move freely for the test. The MT uses the latency for a mouse to fall off an inverted screen as a measure of muscular strength. A mouse is placed on a screen, which is inverted over a clear box, and is timed for their latency to fall. Three trials are performed, with the best of the three trials scored for that day. A score of 60 s is the maximum time a mouse is left inverted. Mice are given a 5-min rest period between mesh test trials. Lastly, an accelerated protocol on the RR assesses motor coordination and endurance. During a trial, a mouse walks on a rotating rod as it increases in speed from 4 rpm to 40 rpm over 5 min. The trial ends when the mouse touches the magnetized pressure sensor upon falling. Each mouse undergoes three trials, and the best trial is scored for that day. This combined behavioral data allows for the global assessment of mobility, coordination, strength, and movement of the test animals. At least two out of the three behavioral testing measures must show improvement for an animal to qualify as having overall improved motor function.

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects of a disease or treatment on an animal's wellbeing. In order to globally assess motor functioning, we selected tests for general locomotion, muscular strength, and coordination: the open field test, the mesh test, and the rotarod test, respectively.

Batterie de Behavioral teste évaluation générale Locomotion, force musculaire et la Coordination chez les souris

Behavioral testing is used in pre-clinical trials to assess the phenotypic effects and outcomes that a particular disease or treatment has on the ...

Systematic Assessment of Well-Being in Mice for Procedures Using General Anesthesia

In keeping with the 3R Principle (Replacement, Reduction, Refinement) developed by Russel and Burch, scientific research should use alternatives to animal experimentation whenever possible. When there is no alternative to animal experimentation, the total number of laboratory animals used should be the minimum needed to obtain valuable data. Moreover, appropriate refinement measures should be applied to minimize pain, suffering, and distress accompanying the experimental procedure. The categories used to classify the degree of pain, suffering, and distress are non-recovery, mild, moderate, or severe (EU Directive 2010/63). To determine which categories apply in individual cases, it is crucial to use scientifically sound tools.
The well-being-assessment protocol presented here is designed for procedures during which general anesthesia is used. The protocol focuses on home cage activity, the Mouse Grimace Scale, and luxury behaviors such as burrowing and nest building behavior as indicators of well-being. It also uses the free exploratory paradigm for trait anxiety-related behavior. Fecal corticosterone metabolites as indicators of acute stress are measured over the 24-h post-anesthetic period.
The protocol provides scientifically solid information on the well-being of mice following general anesthesia. Due to its simplicity, the protocol can easily be adapted and integrated in a planned study. Although it does not provide a scale to classify distress in categories according to the EU Directive 2010/63, it can help researchers estimate the degree of severity of a procedure using scientifically sound data. It provides a way to improve the assessment of well-being in a scientific, animal-centered manner.

We developed a protocol to assess well-being in mice during procedures using general anesthesia. A series of behavioral parameters indicating levels of well-being as well as glucocorticoid metabolites were analyzed. The protocol can serve as a general aid to estimate the degree of severity in a scientific, animal-centered manner.

Évaluation systématique du bien-être chez les souris pour les procédures utilisant l’anesthésie générale

In keeping with the 3R Principle (Replacement, Reduction, Refinement) developed by Russel and Burch, scientific research should use alternatives to animal ...

Measuring Active and Passive Tameness Separately in Mice

Domesticated animals such as dogs and laboratory mice show a high level of tameness, which is important for humans to handle them easily. Tameness has two behavioral components: a reluctance to avoid humans (passive tameness) and a motivation to approach humans (active tameness). To quantify these components in mice, we previously developed behavioral tests for active tameness, passive tameness, and the willingness to stay on a human hand, each designed to be completed within 3 min. The data obtained were used for selective breeding, with a large number of mice analyzed per generation. The active tameness test measures the movement of the mouse toward a human hand and the contact it engages in. The passive tameness test measures the duration of time that a mouse tolerates human touch. In the stay-on-hand test, a mouse is placed on a human hand and touched slowly using the thumb of that hand; the duration of time that the animal remains on the hand is measured. Here, we describe the test set-up and apparatus, explain the procedures, and discuss the appropriate data analysis. Finally, we explain how to interpret the results.

Tameness in animals includes a reduction of avoidance responses to humans (passive tameness) and an increase in active approaches to humans (active tameness). Here, we describe detailed protocols for three behavioral tests (active tameness, passive tameness, and stay-on-hand tests) to separately measure the active and passive tameness of mice.

Mesure Active et Passive docilité séparément chez les souris

Domesticated animals such as dogs and laboratory mice show a high level of tameness, which is important for humans to handle them easily. Tameness has two ...

Measuring Changes in Tactile Sensitivity in the Hind Paw of Mice Using an Electronic von Frey Apparatus

Measuring inflammation-induced changes in thresholds of hind paw withdrawal from mechanical pressure is a useful technique to assess changes in pain perception in rodents. Withdrawal thresholds can be measured first at baseline and then following drug, venom, injury, allergen,&#160;or otherwise evoked inflammation by applying an accurate force on very specific areas of the skin. An electronic von Frey apparatus allows precise assessment of mouse hind paw withdrawal thresholds that are not limited by the available filament sizes in contrast to classical von Frey measurements. The ease and rapidity of measurements allow for incorporation of assessment of tactile sensitivity outcomes in diverse models of rapid-onset inflammatory and neuropathic pain as multiple measurements can be taken within a short time period. Experimental measurements for individual rodent subjects can be internally controlled against individual baseline responses and exclusion criteria easily established to standardize baseline responses within and across experimental groups. Thus, measurements using an electronic von Frey apparatus represent a useful modification of the well-established classical von Frey filament-based assays for rodent mechanical allodynia that may also be applied to other nonhuman mammalian models.

Electronic von Frey measurements are an effective and improved alternative to classical von Frey filaments, as they allow rapid and precise measurement of changes in rodent mechanical withdrawal thresholds to continuously applied pressure stimuli before and after an inflammatory event.

Measuring inflammation-induced changes in thresholds of hind paw withdrawal from mechanical pressure is a useful technique to assess changes in pain ...

Non-invasive Assessment of Dorsiflexor Muscle Function in Mice

Assessment of skeletal muscle contractile function is an important measurement for both clinical and research purposes. Numerous conditions can negatively affect skeletal muscle. This can result in a loss of muscle mass (atrophy) and/or loss of muscle quality (reduced force per unit of muscle mass), both of which are prevalent in chronic disease, muscle-specific disease, immobilization, and aging (sarcopenia). Skeletal muscle function in animals can be evaluated by a range of different tests. All tests have limitations related to the physiological testing environment, and the selection of a specific test often depends on the nature of the experiments. Here, we describe an in vivo, non-invasive technique involving a helpful and easy assessment of force frequency-curve (FFC) in mice that can be performed on the same animal over time. This permits monitoring of disease progression and/or efficacy&#160;of a potential therapeutic treatment.

Measurement of rodent skeletal muscle contractile function is a useful tool that can be used to track disease progression as well as efficacy of therapeutic intervention. We describe here the non-invasive, in vivo assessment of the dorsiflexor muscles that can be repeated over time in the same mouse.

Évaluation non invasif de la fonction musculaire de dorsifléchisseurs chez la souris

Assessment of skeletal muscle contractile function is an important measurement for both clinical and research purposes. Numerous conditions can negatively ...

Médecine

Mechanical Conflict-Avoidance Assay to Measure Pain Behavior in Mice

Pain comprises of both sensory (nociceptive) and affective (unpleasant) dimensions. In preclinical models, pain has traditionally been assessed using reflexive tests that allow inferences regarding pain's nociceptive component but provide little information about the affective or motivational component of pain. Developing tests that capture these components of pain are therefore translationally important. Hence, researchers need to use non-reflexive behavioral assays to study pain perception at that level. Mechanical conflict-avoidance (MCA) is an established voluntary non-reflexive behavior assay, for studying motivational responses to a noxious mechanical stimulus in a 3 chamber paradigm. A change in a mouse's location preference, when faced with competing noxious stimuli, is used to infer the perceived unpleasantness of bright light versus tactile stimulation of the paws. This protocol outlines a modified version of the MCA assay which pain researchers can use to understand affective-motivational responses in a variety of mouse pain models. Though not specifically described here, our example MCA data use the intraplantar complete Freund's adjuvant (CFA), spared nerve injury (SNI), and a fracture/casting model as pain models to illustrate the MCA procedure.

The mechanical conflict-avoidance assay is used as a non-reflexive readout of pain sensitivity in mice which can be used to better understand affective-motivational responses in a variety of mouse pain models.

Test mécanique d’évitement des conflits pour mesurer le comportement de la douleur chez la souris

Pain comprises of both sensory (nociceptive) and affective (unpleasant) dimensions. In preclinical models, pain has traditionally been assessed using ...

In vivo Measurement of Knee Extensor Muscle Function in Mice

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the clinic and the research laboratory, maximal muscular strength is widely measured longitudinally in humans, with knee extensor musculature the most reported functional outcome. Pathology of the knee extensor muscle complex is well documented in aging, orthopedic injury, disease, and disuse; knee extensor strength is closely related to functional capacity and injury risk, underscoring the importance of reliable measurement of knee extensor strength. Repeatable, in vivo assessment of knee extensor strength in pre-clinical rodent studies offers valuable functional endpoints for studies exploring osteoarthritis or knee injury. We report an in vivo and non-invasive protocol to repeatedly measure isometric peak tetanic torque of the knee extensors in mice across time. We demonstrate consistency using this novel method to measure knee extensor strength with repeated assessment in multiple mice producing similar results.

Quantification of knee extensor maximal strength is imperative to understand functional adaptations to aging, disease, injury, and rehabilitation. We present a novel method to repeatedly measure in vivo knee extension isometric peak tetanic torque.

Mesure in vivo de la fonction musculaire extensrice du genou chez la souris

Skeletal muscle plasticity in response to countless conditions and stimuli mediates concurrent functional adaptation, both negative and positive. In the ...

Biologie

Versatility of Protocols for Resistance Training and Assessment Using Static and Dynamic Ladders in Animal Models

Resistance training is a physical exercise model with profound benefits for health throughout life. The use of resistance exercise animal models is a way to gain insight into the underlying molecular mechanisms that orchestrate these adaptations. The aim of this article is to describe exercise models and training protocols designed for strength training and evaluation of resistance in animal models and provide examples. In this article, strength training and resistance evaluation are based on ladder climbing activity, using static and dynamic ladders. These devices allow a variety of training models as well as provide precise control of the main variables which determine resistance exercise: volume, load, velocity, and frequency. Furthermore, unlike resistance exercise in humans, this is a forced exercise. Thus, aversive stimuli must be avoided in this intervention to preserve animal welfare. Prior to implementation, a detailed design is necessary, along with an acclimatization and learning period. Acclimatization to training devices, such as ladders, weights, and clinical tape, as well as to the manipulations required, is necessary to avoid exercise rejection and to minimize stress. At the same time, the animals are taught to climb up the ladder, not down, to the resting area on the top of the ladder. Resistance evaluation can characterize physical strength and permit adjusting and quantifying the training load and the response to training. Furthermore, different types of strength can be evaluated. Regarding training programs, with appropriate design and device use, they can be sufficiently versatile to modulate different types of strength. Furthermore, they should be flexible enough to be modified depending on the adaptive and behavioral response of the animals or the presence of injuries. In conclusion, resistance training and assessment using ladders and weights are versatile methods in animal research.

The present protocol describes resistance training and testing using static and dynamic ladders in animal models.

Polyvalence des protocoles pour l’entraînement et l’évaluation de la résistance à l’aide d’échelles statiques et dynamiques dans des modèles animaux

Resistance training is a physical exercise model with profound benefits for health throughout life. The use of resistance exercise animal models is a way ...