The Wellcome Trust for providing Open Access funding to Oxford University. Robert Deacon is a member of Oxford OXION group, funded by Wellcome Trust grant WT084655MA.

1. Apparatus
1.1 Kondziela's inverted screen test
The inverted screen is a 43 cm square of wire mesh consisting of 12 mm squares of 1 mm diameter wire (Figure 1). It is surrounded by a 4 cm deep wooden beading (which prevents the occasional mouse which attempts to from climbing on to the other side) (Figure 2).
1.2 Weights test
Seven weights constitute the apparatus. Each consists of a ball of tangled fine gauge stainless steel wire, a "scale collector" as used to prevent limestone scale formation in domestic kettles. The weight of this is small (7 g) but each scale collector is attached to a series of steel chain links, each weighing approximately 13 g. The number of links ranges from one to seven. Their weights are therefore: 20, 33, 46, 59, 72, 85 and 98 g (Figures 3 and 4).
2. Procedure
For all tests, bring the mice to the experimental room 5-20 min before testing to ensure they are properly awake. As a general rule, to allow recovery of muscular strength and a return to normal levels of arousal, rest the mice by a return to the home cage after each motor test.
<ol>
	<li>Kondziela's inverted screen test</li>
	<li>Procedure: Place the mouse in the center of the wire mesh screen, start a stopclock, rotate the screen to an inverted position over 2 sec, with the mouse's head declining first. Hold the screen steadily 40-50 cm above a padded surface. Note the time when the mouse falls off, or remove it when the criterion time of 60 sec is reached. Longer criterion times may be useful for some experiments.</li>
	<li>Scoring the inverted screen:</li>
</ol>
Falling between 1-10 sec = 1 
Falling between 11-25 sec = 2 
Falling between 26-60 sec = 3 
Falling after 60 sec = 4
Or, e.g. for 2 min: 
Falling between 1-10 sec = 1 
Falling between 11-25 sec = 2 
Falling between 26-60 sec = 3 
Falling between 61-90 sec = 4 
Falling after 90 sec = 5
3. Weights Test
Hold a mouse by the middle/base of the tail and lower it to allow it to grasp the first weight (20 g) which is lying on the laboratory bench. As it grasps the wire scale collector with its forepaws, start a stop clock and raise the mouse until the link is clear of the bench. A hold of three seconds is the criterion. If the mouse drops the weight in less than 3 sec, note the time it held the weight. Rest the mouse for about 10 sec and try it on the weight once again. If it fails three times, that terminates the trial, and the mouse is assigned the maximum time/weight achieved. If it holds it for 3 sec then try it on the next heaviest weight. If it lifts this for 3 sec, test it on the next heavier weight, after you have tested all its cagemates on the first weight. Again, it is given three chances to hold the weight for 3 sec. A final total score is calculated as the product of the number of links in the heaviest chain held for the full 3 sec, multiplied by the time (sec) it is held. If the heaviest weight is dropped before 3 sec an appropriate intermediate value is calculated. Thus a mouse holding a 5-link weight for 3 seconds, but unable to lift a 6-link weight, is assigned a score of (5 x 3) = 15. If it holds the 6-link weight for 1 second, it scores (5 x 3) + (1) =16.
Sometimes mice may not be adequately motivated to grip the apparatus. This generally occurs in older animals. This problem can be minimized by holding the mice by the tail for a longer time before bringing it within gripping distance of the wire ball.

<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>

No conflicts of interest declared.

Mouse models of the many diseases that affect the human motor systems are continually being developed, therefore good assays of strength in mice are essential. Examples include the many forms of muscular dystrophy, Parkinson's disease and Huntington's chorea. Strength assays also find use in models of nerve regeneration after spinal or peripheral nerve damage. Industrial and automobile accidents continue to cause considerable disability to humans, but much preclinical work is presently investigating possible avenues of treatment based on nerve growth factors.
Muscles never work individually. They are activated by the brain, local or higher spinal reflexes, via the neuromuscular junctions and work within the constraints of other muscles and the skeletal system. Therefore, the complexity of the system means in vivo assays of muscular force in the awake animal are essential in the evaluation of its present condition and the effects of any putative treatments. Mice instinctively hold on to materials with a strong grip, thus Mus musculus is an ideal model animal in which to assess disorders of muscular strength and possible treatments.

To a lay person, the idea of measuring strength in mice might appear absurd, even something of an oxymoron. However, it is not without reason that house/lab mice are named Mus musculus. They actually have a very high strength/weight ratio, greater than that of rats. For instance, adult mice can easily support their own body weight, even using only the fore or hind paws; very few adult lab rats can do this.
Mice are playing an ever greater role in biomedical research. They can be used to model many human motor disorders, both somatic and central nervous system in origin. The former include the more than thirty forms of inherited muscular dystrophy1 and myasthenia gravis, while examples of the latter are multiple sclerosis, spinal muscular atrophy, Parkinson's disease, Huntington's disease and amyotrophic lateral sclerosis. For all of these models, a full assessment of their motor deficits must include specific tests of strength.

measuring the strength of mice

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 maximum on this task; it is a quick but insensitive gross screen, and the weights test described in this article will provide a finer measure of muscular strength.
There are also several strain gauge-based pieces of apparatus available commercially that will provide more graded data than the inverted screen test, but their cost may put them beyond the reach of many laboratories which do not specialize in strength testing. Hence in 2000 a cheap and simple apparatus was devised by the author. It consists of a series of chain links of increasing length, attached to a "fur collector" a ball of fine wire mesh sold for preventing limescale build up in hard water areas. An accidental observation revealed that mice could grip these very tightly, so they proved ideal as a grip point for a weight-lifting apparatus. A common fault with commercial strength meters is that the bar or other grip feature is not thin enough for mice to exert a maximum grip. As a general rule, the thinner the wire or bar, the better a mouse can grip with its small claws.
This is a pure test of strength, although as for any test motivational factors could potentially play a role. The use of scale collectors, however, seems to minimize motivational problems as the motivation appears to be very high for most normal young adult mice.

Expected Results
Contet et al.2 demonstrated that 129S2/sv mice performed similarly on the weights test to C57BL/6 mice. Female C57BL/6 mice scored approximately 15, 129 mice 17, which means they could lift approximately 5 chain links, around 70 g. This is a high value; normally 2-3 chain links (score 6-9, 33-46 g) are lifted by C57BL/6 mice5. These differences are presumably related to factors such as how much handling the mice have received and the details of the experimenter's technique.
Hippocampal lesions did not affect strength as measured either by the weights test or the inverted screen4. Prion (scrapie) diseased mice were impaired on the inverted screen by 18 weeks after infection6. Although somewhat impaired on the horizontal bar and rotarod relative to C57BL/6 mice, C57BL/10 mice were not impaired on weightlifting5. Knockout mice for the KATP channel subunit Kir6.2 were not impaired on the inverted screen or weightlifting tests, although the females scored higher than males on the latter3. This was unusual; normally the heavier males display greater strength than the females.
<img alt="Figure 1" src="/files/ftp_upload/2610/2610fig1.jpg" /> 
 Figure 1. The inverted screen.
<img alt="Figure 2" src="/files/ftp_upload/2610/2610fig2.jpg" /> 
 Figure 2. Close view of a mouse on the inverted screen.
<img alt="Figure 3" src="/files/ftp_upload/2610/2610fig3.jpg" /> 
 Figure 3. Weights, ranging from 20 g to 98 g.
<img alt="Figure 4" src="/files/ftp_upload/2610/2610fig4.jpg" /> 
 Figure 4. A mouse weightlifting.

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

Measuring the Strength of Mice

Deficits in muscular strength occur in many clinical conditions such as motor neuron disease. The inverted screen and weight lifting tests described here measure strength in mice almost exclusively, with minimal influence of factors such as coordination.

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 ...

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53.8K Views.  University of Oxford. Deficits in muscular strength occur in many clinical conditions such as motor neuron disease. The inverted screen and weight lifting tests described here measure strength in mice almost exclusively, with minimal influence of factors such as coordination.

Video: Measuring the Strength of Mice

Programmed Electrical Stimulation in Mice

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ventricular arrhythmias, and sudden cardiac death.1 Intracardiac pacing studies can be performed in mice using a 1.1F octapolar catheter inserted into the jugular vein, and advanced into the right atrium and ventricle. Here, we illustrate the steps involved in performing programmed electrical stimulation in mice. Surface ECG and intracardiac electrograms are recorded simultaneously in the atria, atrioventricular junction, and ventricular myocardium, whereas intracardiac pacing of the atrium is performed using an external stimulator. Thus, programmed electrical stimulation in mice provides unique opportunities to explore molecular mechanisms underlying conduction defects and cardiac arrhythmias.

Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ...

Transthoracic Echocardiography in Mice

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,6 whereas TDI is used to measure the velocity of myocardial motion.7 Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene ...

Manual Muscle Testing:  A Method of Measuring Extremity Muscle Strength Applied to Critically Ill Patients

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, and persistent nerve and muscle impairments after hospital discharge.1-6 Using an explicit protocol with a structured approach to training and quality assurance of research staff, manual muscle testing (MMT) is a highly reliable method for assessing strength, using a standardized clinical examination, for patients following ARDS, and can be completed with mechanically ventilated patients who can tolerate sitting upright in bed and are able to follow two-step commands. 7, 8 
This video demonstrates a protocol for MMT, which has been taught to &ge;43 research staff who have performed &gt;800 assessments on &gt;280 ARDS survivors. Modifications for the bedridden patient are included. Each muscle is tested with specific techniques for positioning, stabilization, resistance, and palpation for each score of the 6-point ordinal Medical Research Council scale.7,9-11 Three upper and three lower extremity muscles are graded in this protocol: shoulder abduction, elbow flexion, wrist extension, hip flexion, knee extension, and ankle dorsiflexion. These muscles were chosen based on the standard approach for evaluating patients for ICU-acquired weakness used in prior publications. 1,2.

Survivors of acute respiratory distress syndrome (ARDS) and critical illness frequently develop long-lasting muscle weakness. Manual muscle testing (MMT) is a standardized clinical examination commonly used to measure strength of peripheral skeletal muscle groups. This video demonstrates MMT using the 6-point Medical Research Council scale.

Survivors of acute respiratory distress syndrome (ARDS) and other causes of critical illness often have generalized weakness, reduced exercise tolerance, ...

Orthotopic Aortic Transplantation in Mice for the Study of Vascular Disease

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. This is largely true, but there are a number of important principles that can reduce the difficulty of these procedures and enhance reproducibility. Orthotopic aortic transplantation is an excellent procedure in which to learn these principles because it involves only two end-to-end anastomoses, but requires good suturing technique and handling of the vessels for consistent success. This procedure begins with the procurement of a length of abdominal aorta from a donor animal, followed by division of the native aorta in the recipient. The procured aorta is then placed between the divided ends of the recipient aorta and sutured into place using end-to-end anastomoses. To accomplish this objective successfully requires a high degree of concentration, good tools, a steady hand, and an appreciation of how easily the vasculature of a mouse can be damaged, resulting in thrombosis. Learning these important principles is what occupies most of the beginner's time when learning microsurgery in small rodents. Throughout this protocol, we refer to these important points. This model can be used to study vascular disease in a variety of different experimental systems1-8. In the context shown here, it is most often used for the study of post-transplant vascular disease, a common long-term complication of solid organ transplantation in which intimal hyperplasia occurs within the allograft. The primary advantage of the model is that it facilitates quantitative morphometric analyses and the transplanted vessel lies contiguous to the endogenous vessel, which can serve as an additional control9. The technique shown here is most often used for mice weighing 18-25 grams. We have accumulated most of our experience using the C57BL/6J, BALB/cJ, and C3H/HeJ strains.

We describe a technique in which a section of the abdominal aorta from a mouse is transplanted orthotopically to just below the renal arteries in an allogeneic or syngeneic recipient. This technique can be useful in studies in which transplantation of large arteries of uniform size is deemed advantageous.

Vascular procedures involving anastomoses in the mouse are generally thought to be difficult and highly dependent on the skill of the individual surgeon. ...

Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound

We present a protocol for measuring in vivo aortic stiffness in mice using high-resolution ultrasound imaging. Aortic diameter is measured by ultrasound and aortic blood pressure is measured invasively with a solid-state pressure catheter. Blood pressure is raised then lowered incrementally by intravenous infusion of vasoactive drugs phenylephrine and sodium nitroprusside. Aortic diameter is measured for each pressure step to characterize the pressure-diameter relationship of the ascending aorta. Stiffness indices derived from the pressure-diameter relationship can be calculated from the data collected. Calculation of arterial compliance is described in this protocol.
This technique can be used to investigate mechanisms underlying increased aortic stiffness associated with cardiovascular disease and aging. The technique produces a physiologically relevant measure of stiffness compared to ex vivo approaches because physiological influences on aortic stiffness are incorporated in the measurement. The primary limitation of this technique is the measurement error introduced from the movement of the aorta during the cardiac cycle. This motion can be compensated by adjusting the location of the probe with the aortic movement as well as making multiple measurements of the aortic pressure-diameter relationship and expanding the experimental group size.

Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound

We describe a technique for measuring aortic stiffness from its pressure-diameter relationship in vivo in mice. Aortic diameter is recorded by ultrasound and aortic pressure is measured invasively with a solid-state pressure catheter. Blood pressure is changed incrementally and the resulting diameter is measured.

We present a protocol for measuring in vivo aortic stiffness in mice using high-resolution ultrasound imaging. Aortic diameter is measured by ultrasound ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Improving Strength, Power, Muscle Aerobic Capacity, and Glucose Tolerance through Short-term Progressive Strength Training Among Elderly People

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in elderly people performing short-term resistance training (RET). Supervised progressive resistance training for 1 h three times a week over 8 weeks was performed by RET participants (71&#177;1 years, range 65-80). Compared to a control group without training, the RET showed improvements on the measures used to indicate strength, power, glucose tolerance, and several parameters of muscle aerobic capacity. Strength training was performed in a gym with only robust fitness equipment. An isokinetic dynamometer for knee extensor strength permitted the measurement of concentric, eccentric, and static strength, which increased for the RET group (8-12% post- versus pre-test). The power (rate of force development, RFD) at the initial 0-30 ms also showed an increase for the RET group (52%). A glucose tolerance test with frequent blood glucose measurements showed improvements only for the RET group in terms of blood glucose values after 2 h (14%) and the area under the curve (21%). The blood lipid profile also improved (8%). From muscle biopsy samples prepared using histochemistry, the amount of fiber type IIa increased, and a trend towards a decrease in IIx in the RET group reflected a change to a more oxidative profile in terms of fiber composition. Western blot (to determine the protein content related to the signaling for muscle protein synthesis) showed a rise of 69% in both Akt and mTOR in the RET group; this also showed an increase in mitochondrial proteins for OXPHOS complex II and citrate synthase (both ~30%) and for complex IV (90%), in only the RET group. We demonstrate that this type of progressive resistance training offers various improvements (e.g., strength, power, aerobic capacity, glucose tolerance, and plasma lipid profile).

The effect of short-term resistance training on elderly people was investigated through the simultaneous use of several methods. Compared to a control group, many improvements were seen, including on muscle aerobic capacity, glucose tolerance, strength, power, and muscle quality (i.e., protein involved in cell signaling and muscle fiber type composition).

This protocol describes the simultaneous use of a broad span of methods to examine muscle aerobic capacity, glucose tolerance, strength, and power in ...

Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

Toxicological evaluation is crucial for understanding the effects of chemicals on living organisms in basic and applied biological science fields. A non-mammalian soil round worm, Caenorhabditis elegans, is a valuable model organism for toxicology studies due to its convenience and lack of animal ethics issues compared with mammalian animal systems. In this protocol, a detailed procedure of toxicological evaluation of chemicals in C. elegans is described. A clinical anticancer drug, etoposide, which targets human topoisomerase II and inhibits DNA replication of human cancer cells, was selected as a model testing chemical. Age-synchronized C. elegans eggs were exposed to either dimethyl sulfoxide (DMSO) or etoposide, and then the growth of C. elegans was monitored every day for 4 days by the stereo microscope observation. The total number of eggs laid from C. elegans treated with DMSO or etoposide was also counted by using the stereo microscope. Etoposide treatment significantly affected the growth and reproduction of C. elegans. By comparison of the total number of eggs laid from worms with different treatment periods of chemicals, it can be decided that the reproductive toxicity of chemicals on C. elegans reproduction is reversible or irreversible. These protocols may be helpful for both the development of various drugs and risk assessment of environmental toxicants.

Measuring the Effect of Chemicals on the Growth and Reproduction of Caenorhabditis elegans

A basic protocol to evaluate the toxicity of chemicals in a model animal, Caenorhabditis elegans, is described. The method is convenient and useful for the development of pharmaceuticals as well as for the risk assessment of various environmental pollutants.

Toxicological evaluation is crucial for understanding the effects of chemicals on living organisms in basic and applied biological science fields. A ...

Assessment and Characterization of Hyaloid Vessels in Mice

In the eye, the embryonic hyaloid vessels nourish the developing lens and retina and regress when the retinal vessels develop. Persistent or failed regression of hyaloid vessels can be seen in diseases such as persistent hyperplastic primary vitreous (PHPV), leading to an obstructed light path and impaired visual function. Understanding the mechanisms underlying the hyaloid vessel regression may lead to new molecular insights into the vascular regression process and potential new ways to manage diseases with persistent hyaloid vessels. Here we describe the procedures for imaging hyaloid in live mice with optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) and a detailed technical protocol of isolating and flat-mounting hyaloid ex vivo for quantitative analysis. Low-density lipoprotein receptor-related protein 5 (LRP5) knockout mice were used as an experimental model of persistent hyaloid vessels, to illustrate the techniques. Together, these techniques may facilitate a thorough assessment of hyaloid vessels as an experimental model of vascular regression and studies on the mechanism of persistent hyaloid vessels.

This protocol describes both in vivo and ex vivo methods to fully visualize and characterize hyaloid vessels, a model of vascular regression in mouse eyes, using optical coherence tomography and fundus fluorescein angiography for the live imaging and ex vivo isolation and subsequent flat mount of hyaloid for quantitative analysis.

In the eye, the embryonic hyaloid vessels nourish the developing lens and retina and regress when the retinal vessels develop. Persistent or failed ...

Blood Collection Through Subclavian Vein Puncture in Mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

Here, we present a protocol to take blood samples from the subclavian vein of mice.

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...