Tag Archives: mice

Weekly Roundup: Ending the vaccine-autism myth, spider venom for stroke victims, and causes of polycystic ovary syndrome

Welcome to our third weekly roundups. These Friday posts aim to inform our readers about the many stories that relate to animal research each week. Do you have an animal research story we should include in next week’s roundup? You can send it to us via our Facebook page or through the contact form on the website.

  • Studies on the relation between the environment and autism are starting to build, ending the vaccine-autism myth started in 1998. No vaccination has met the criteria of being a cause of autism – although some environmental factors increase the risk two to four times. Our understanding of many of these risk factors has been greatly increased with the help of animal research. For example, mouse research on the relation between maternal immune activation and autism-like phenotypes was later found to be consistent in human populations. Also, links to prenatal exposure to medications with teratogens were investigated in rats and found to be consistent with humans.
  • Spiders venom saves stroke victims: Funnel-web spiders are among the world’s deadliest spiders, but their venom can be life-saving. Since the venom targets the prey’s nervous system, researchers tested whether it could be harnessed to reverse brain damage after a stroke. After traveling to Fraser Island to collect three Darling Downs funnel-web spiders, researchers at University of Queensland and Monash University “milked” the spiders to collect their venom, then isolated a protein called Hi1a — a molecule that closely resembles another known for its protective effect on neurons. The team then synthesized their own version of Hi1a and gave the compound to rats two hours after an induced stroke. Neuron damage was reduced by 80 percent. Eight hours after a stroke, it was still effective in restoring neurological and motor functions by almost 65 percent. The researchers hope to commence human clinical trials in the next few years, pending replication of these initial findings and further research into the molecule.

  • A new study has found that polycystic ovary syndrome (PCOS) may start in the brain, not the ovaries, contrary to previous belief. While the cause of PCOS is unknown, one feature of this syndrome is high levels of androgens. Using a high dose of androgens, PCOS was induced in genetically engineered mice which display a receptor for androgens in specific parts of the body (brain, ovaries, nowhere in the body and a normal control group). Mice with androgen receptors in the normal control group developed PCOS as expected, while those without receptors in the brain and in the entire body did not. Interestingly, mice without androgen receptors in the ovaries also developed PCOS albeit at a lower rate than the control group. These data replicate the finding that high levels of androgens are implicated in the development of PCOS. More importantly, they highlight that it may be the interaction of these androgen in the brain rather than the ovaries that lead to the development of PCOS. PCOS affects 5-10% of women aged 18 to 44 and this study, using mice, has provided valuable insight into the onset of this syndrome.

  • A new study finds in mice that whole body vibration (WBV), a less intensive form of regular exercise, mimics the benefits derived from regular exercise. To investigate the benefits of WBV, scientists exposed normal mice and mice which don’t produce a receptor for leptin (a hormone associated with the feeling of being full after eating) to no exercise, either daily treadmill exercise, or WBV for three months. They found that in the normal mice and the leptin-deficient mice, WBV and exercise, affected mice in a similar way — reduced body weight, enhanced muscle mass, and insulin sensitivity compared to mice that were sedentary (no exercise group). This research, using mice, suggests that WBV may be useful as a supplemental therapy for individuals suffering from metabolic disorders or morbid obesity and where regular exercise is not an option.
  • Researchers have created a backpack-sized artificial lung that was able to fully oxygenate the blood of sheep for six hours. William Federspiel, at the University of Pittsburgh, has subsequently said the device has been used successfully on sheep for five days. The device had to combine a pump and gas exchange while remaining small enough to be carried. Even smaller devices have been developed to work on rats, using ultrathin tubing, just 20 micrometers in diameter. Such technologies could allow people with lung failure to continue with many of their daily activities, rather than becoming bed-ridden and attached to today’s artificial lung machines.

Image Credit: William Federspiel

  • A study funded by the NC3Rs explores how different handling methods affected behavior in cognitive tasks. Tail handling is still one of the more common methods of handling mice in the laboratory despite variable evidence that alternative methods such as cupped or tunnel handling may be less stressful for the animal. The researchers compared how mice reacted to new stimuli after being transferred into the testing area via a tunnel or being picked up by the tail. Because being picked up by the tail may be stressful for mice, tests which involve exploration may be affected by tail handling – as one consequence of stress in mice is freezing behavior (staying immobile). They found that the tunnel handling facilitated greater exploratory behavior, indicating that the simple process of tail handling may confound behavioral measures relating to anxiety. 3Rs research like this can help to understand the needs of animals in research labs, with the aim of improving animal welfare and the replicability of experimental results.

Image Credit: Jane Hurst, University of Liverpool.

Speaking of Research

Tail or Tunnel: Handling Methods Influence Mouse Behavior in Cognitive Tasks

  • A study funded by the NC3Rs explored how handling methods influenced mice’s behavior during cognitive tasks
  • Mice were either picked up by the tail or guided into a tunnel, then transferred to the testing arena
  • Mice that were transferred in the tunnel were far more exploratory during the cognitive task
  • Acclimation to handling procedures is important

A new study published today in Scientific Reports shows that the way experimenters pick up mice can affect their behavior during cognitive tasks. The study was funded by the NC3Rs, which is dedicated to replacing, refining, and reducing the use of animals in research and testing. This particular study focused on refinement: identifying optimal handling methods for mice has important implications for both the welfare of the animals and the validity and usability of data that are collected, which could potentially lead to a reduction in the need for animals in future studies.

Image Credit: Jane Hurst, University of Liverpool.

Drs. Kelly Gouveia and Jane Hurst first placed laboratory mice near a new, attractive stimulus – urine from a novel mouse of the opposite sex – that is known to stimulate approach and investigation. The mice were allowed three sessions to grow accustomed to the new scent. Throughout all three sessions, mice were either picked up by the tail (standard laboratory practice, though there is no obvious scientific reasoning for this method) or were guided into a clear tunnel that is both affordable and easily sterilized. (The method is also easy to learn.) Mice were then carried to the test arena either by the tail or in the tunnel and allowed to explore. Gouveia and Hurst report that mice picked up by the tail showed very little willingness to explore the test arena, and therefore investigate the new stimulus, whereas those transported in the tunnel showed much higher exploration and a strong interest in the new scent.

Importantly, Gouveia and Hurst then tested the mice’s ability to discriminate between the (formerly) new scent and a second, different urine stimulus. They report that since the mice picked up by the tail performed so poorly from the start, they did not discriminate between the two scents. However, those transported in the tunnel showed robust and reliable discrimination. These findings are noteworthy not only with respect to the psychological welfare of the animals, but also for the important effects that handling and habituation have on yielding usable, reliable data. With the potential to reduce the stress associated with handling, the tunnel method could reduce the anxiety that mice display upon tail handling – thereby resulting in more species-typical behaviors, such as exploration of a novel, conspecific scent. It could also reduce the uncontrolled variation that exists in animal studies and could ultimately produce more reliable data. Thus, identifying optimal handling techniques has the potential to reduce the number of animals needed in laboratory studies in addition to refining the techniques used to study them and enhance their welfare.

Image Credit: Jane Hurst, University of Liverpool.

It is worth noting that a study by Novak and colleagues (2015) found no difference in cognitive performance between mice that were handled by the tail or by a less invasive method (“cupping” in the experimenter’s hands). Why might no difference have been found in this study? One possibility is that the cognitive task the researchers used was different from the present study (a radial arm maze vs. novel scent), and the arm maze may probe for different behaviors than a novel odor task. Another possibility is that perhaps mice “prefer” the tunnel to both tail handling and cupping, but neither the 2015 nor the present study compared all three methods. Hurst and her colleague Rebecca West did compare all three methods in a 2010 study, however, and found that mice preferred both the tunnel and cupping method to tail handling (as assessed by voluntary interaction time with the experimenter); although the cupping method produced more variable results depending on strain and sex. However, in the Novak study, mice were handled daily for many weeks, whereas in the Hurst & West study they were handled only for nine days. Of course, the most parsimonious explanation is that in every handling study, experimenter interaction is confounded with handling. That is, are the mice acclimating to the experimenters, to the handling procedures, or both?

These questions underscore the need for replication before firm conclusions about optimal handling techniques can be drawn. Nevertheless, the findings published today in Scientific Reports are an important addition to the field of animal welfare, and they emphasize the importance of constant, rigorous studies surrounding welfare issues.

Amanda Dettmer

References:

Gouveia K, Hurst JL (2017) Optimising reliability of mouse performance in behavioural testing: the major role of non-aversive handling. Scientific Reports 7: 44999. doi: 10.1038/srep44999

Hurst JL, West RS (2010) Taming anxiety in laboratory mice. Nature Methods. Oct;7(10): 825-6

Novak J, Bailoo JD, Melotti L, Rommen J, Würbel H (2015) An Exploration Based Cognitive Bias Test for Mice: Effects of Handling Method and Stereotypic Behaviour. PLoS ONE 10(7): e0130718. doi:10.1371/journal.pone.0130718

SYR: The case for using large animal models to study reproduction

michelle-bedenbaughThis guest post is written by Michelle Bedenbaugh, a Ph.D. student in the Physiology and Pharmacology Department at West Virginia University. It is part of our Speaking of Your Research series of posts where scientists discuss their own research. Michelle’s research involves examining the brain’s role in the initiation of puberty.  In this post, Michelle discusses the benefits of using large animal models to study reproduction.  If you would be willing to write a guest article for Speaking of Research, please contact us here.

With the increasing pressure to publish papers and the decreasing amount of funds made available to conduct experiments, it has become more difficult for researchers to survive and thrive in an academic setting (see here, here, and here). Scientists have had to adapt, and in many situations, this has led to a significant amount of research that relies heavily on small animal models, including rodents and invertebrates.  In addition to being less expensive than large animal models (sheep, pigs, cows, horses, etc.) there are also more genetic tools and techniques available to use in small animal models.  For example, transgenic mice, where certain genes can be either deleted or overexpressed, are used commonly by researchers worldwide.  Other cutting edge techniques, like optogenetics, where light can be used to control the activity of cells in the brain, are also being used on a more routine basis in rodent models and currently don’t exist in large animal models.

Optogenetics involved using light to control genetically modified cells inside the body

Optogenetics involved using light to turn off or on cells in the brain

While it is most likely easier, cheaper, and faster to conduct experiments using small animal models, in certain situations they are not always the most comparable to humans.  When modeling certain diseases or understanding certain physiological processes, larger animals, like sheep, pigs, and cows, provide a better model for scientists.  This post aims to look at some areas where larger mammals can provide important knowledge or understanding.

A few of the more obvious benefits to using large animal models when compared to small animal models are that large animals are more analogous to humans in regards to body size, organ size, and lifespan.  In addition to these similarities, animals like sheep, cows, and pigs are much less inbred when compared to rodents.  Some would argue that it is advantageous to use animals that are highly inbred because this decreases the amount of variability in an experiment.  However, each human has a unique genetic makeup, and sometimes solutions for problems in inbred rodents cannot be translated for use in humans.  Therefore, in these instances, it is probably more beneficial to use a less inbred large animal model.  Most large animal models also have the added benefit of being an economically important species.  The majority of researchers who use large animal models are attempting to find solutions to health issues that are present in humans.  However, successful experiments in large animal models have the ability to affect both human and animal health.  For example, if a researcher made an important discovery about the way food intake is controlled in cows, it would have the possibility of improving human health, as well as increasing profitability for cattle producers.  Because cows are very similar to sheep, it may also benefit sheep production as well.  Rodents are not an economically important species that provides food, fiber, or other essential products used by the human population.  Consequently, discoveries made in rodents and other small animal models may only benefit humans if the results are translatable.

My particular research focuses on furthering our understanding of how puberty is initiated in girls, and we use sheep as our animal model.  I won’t get into the specific benefits of using sheep to conduct puberty research today because I will discuss this more in my next post.  However, I did want to touch briefly on some of the advantages of using large animals to perform research used to study reproduction in a broader sense.

The brain plays an essential role in controlling reproductive processes.  The brain structure of large animals is more closely related to humans than small animals because large species have a sulcated cortex (meaning the surface of the brain is wrinkly) as opposed to small animal species which have a smooth cortex.

Comparison between mouse (smooth cortex) and human (sulcated cortex) brain. [Credit: Elizabeth Atkinson, Washington University in St. Louis]

Comparison between mouse (smooth cortex) and human (sulcated cortex) brain. [Credit: Elizabeth Atkinson, Washington University in St. Louis]

Sheep also have the advantage of their brain and the cellular pathways present within it being similarly organized to what is observed in non-human primates.  Hormones serve a major role in relaying information from the brain to reproductive organs and vice versa.  The actions of several hormones that aid in controlling reproduction in female sheep (like estrogen and progesterone) parallel the actions of these hormones in humans.  Older sheep also have a similar response to estrogen replacement therapy when compared to post-menopausal women.  The development and function of several structures on the ovary of sheep is also similar to that which is observed in women.  These structures have a major influence on the reproductive cycle and are critical for the maturation of female gametes (sometimes referred to as eggs).  Assisted reproductive technologies, many of which are used for in vitro fertilization (IVF) protocols in women who are having trouble conceiving, have been adapted from procedures used in livestock species.  For example, artificial insemination, where semen is collected from a male and usually frozen so that it can be used to inseminate a female at a later time, is commonly used in cows, sheep, horses and pigs and is similar to procedures conducted in humans.

Credit: Livestock Breeding Services - http://www.livestockbreedingservices.com.au/images/servicesai.jpg

A laparoscopic procedure is used to artificially inseminate sheep

 

Embryo transfer, where embryos from one female are placed into the uterus of another female, are also used in livestock species and humans.  In addition, sheep are also an excellent animal model for studying pregnancy.  Sheep are used often to examine how stress, maternal nutrition, and exposure to excess hormones or toxins affect the development of a fetus.

These are just a few examples that display reproductive processes occurring in many large animal species are easily relatable to those same processes which also occur in humans.  I only touched on a few species today, but there are many more animal models that are underused in research and would serve as great models for humans.  In addition, I only discussed some of the ways these animals can be used to study reproduction when in fact they can be used to mimic many other biological processes that occur in humans.  Depending on the subject matter being researched, the use of some animal models is more appropriate than others.  Regardless of cost or time, researchers should always consider which animal model may be the most appropriate for their experiments.  I believe conducting research in a variety of species as opposed to just one or two species will always be more advantageous and will aid us in solving health issues in humans more quickly.

Michelle Bedenbaugh

When are rats, mice, birds and fish protected by US federal laws?

There is sometimes confusion about how US law protects rats, mice and non-mammalian vertebrates such as birds and fish. Much of this confusion is rooted in the fact that the US Animal Welfare Act (AWA) explicitly excludes purpose-bred rodents (rats of the genus Rattus rattus, mice of the genus Mus mus), as well as birds that were specifically bred for research. Research with these purpose-bred rats and mice likely comprises the overwhelming majority of vertebrate animals in research in the US, but it is not overseen by the United States Department of Agriculture (USDA).

Sometimes this fact is used mistakenly (or perhaps purposely?) to suggest that all species not covered by the Animal Welfare Act are not protected by any federal laws.

Claims that research with non-AWA-covered species is not subject to care standards, external oversight, and public transparency are demonstrably untrue.

This post aims to address these misconceptions by looking at when and how rats, mice, and birds in research are covered by federal laws.

Mouse Science

Image from Understanding Animal Research

In the US, both the USDA, through the Animal and Plant Health Inspection Service (APHIS), and the Department of Health and Human Services (DHHS), through the Public Health Service (PHS) and National Institutes of Health (NIH) Office of Laboratory Animal Welfare (OLAW), are responsible for the oversight animal research. The table below provides a broad overview of the federal regulation and oversight agencies for different species and types of research.

Covered species are defined as: "with certain exceptions, any live or dead dog, cat, monkey (nonhuman primate mammal), guinea pig, hamster, rabbit, or such other warm-blooded animal, as the Secretary [of Agriculture] may determine is being used, or is intended for use for research”

Overview of animal research regulation in the US. The Animal Welfare Act (AWA) states that covered species are defined as: “with certain exceptions, any live or dead dog, cat, monkey (nonhuman primate mammal), guinea pig, hamster, rabbit, or such other warm-blooded animal, as the Secretary [of Agriculture] may determine is being used, or is intended for use for research” (7 U.S.C. 2132(g) The 2002 Farm Bill amended this definition to exclude purpose-bred rats, mice, and birds from the provisions of the AWA. Note that certain types of research with animals and most animal testing are also subject to regulation and oversight by the US Food and Drug Administration (FDA).

Animal Welfare Act (AWA) and USDA. The USDA is charged with enforcement of the AWA. The AWA applies to research with a range of species that includes: “with certain exceptions, any live or dead dog, cat, monkey (nonhuman primate mammal), guinea pig, hamster, rabbit, or such other warm-blooded animal, as the Secretary [of Agriculture] may determine is being used, or is intended for use for research” (7 U.S.C. 2132(g), referred to here as “USDA-covered species.” Institutions that engage in research with covered species must be registered with the USDA.  The AWA also applies to zoos, entertainment facilities, breeders, and other facilities that engage covered species in activities that involve public contact. All such facilities must be licensed by the USDA and research may also be conducted in facilities licensed for non-research purposes.

An amendment to the 2002 Farm Bill  specifically excluded from AWA oversight rats of the genus Rattus rattus, mice of the genus Mus mus, and birds specifically bred for research. Thus, research with these rats, mice, and birds, which likely comprises the overwhelming majority of vertebrate animals in research in the US, is not overseen by the USDA.

Does that mean rats, mice, and birds are not covered by federal animal welfare laws?

It depends on the funding! In fact, many rats, mice, and birds bred for research are covered by federal law.

Why?  Because, for federally-funded research, another federal regulation specifies the conditions for animal care, animal research, external oversight, and associated public transparency via a second federal agency. This includes, for example, university research funded by the National Institutes of Health, the National Science Foundation, or other federal agencies.

PHS and OLAW. The Health Research Extension Act (HREA; 1985) provides the statutory authority for the PHS Policy on Humane Care and Use of Laboratory Animals (PHS Policy), which applies to all PHS-funded research with live vertebrate animals.  In brief, such research must follow the National Research Council’s Guide for the Care and Use of Animals in Research (The Guide) (NRC, 2011).  Each institution receiving PHS funding for research with vertebrate animals is required to have an Assurance of Compliance (Assurance) with OLAW. The Assurance describes policies and procedures adopted by the institution in order to comply with PHS Policy.

The NIH website provides extensive information about PHS policy and OLAW.

http://grants.nih.gov/grants/olaw/faqs.htm

Guide for the Care and Use of Laboratory Animals

Guide for the Care and Use of Laboratory Animals

Food and Drug Administration (FDA). Certain types of research with animals and most animal testing are also subject to oversight and regulation by the US FDA.

Part of the federal regulation governing animal research also requires that each institution engaged in research has a mechanism for ethical consideration, approval, oversight and monitoring of animal care and research. Thus, there are also oversight bodies at each institution that are charged with the approval, monitoring, and reporting of activities with animals.

Institutional Animal Care and Use Committees (IACUC). Animal research oversight at the institutional level is entrusted to an Institutional Animal Care and Use Committee or “IACUC.” The responsibilities of the IACUC are spelled out in the AWA regulations and the PHS policy. Read more about IACUC here: http://grants.nih.gov/grants/olaw/tutorial/iacuc.htm

What about rats, mice, and birds that are not in federally-funded research?

While privately-funded research is not subject to the AWA or PHS Policy, there are other mechanisms that are used to ensure standards of animal care and research review, such as voluntary accreditation of the institutions’ animal care program. Such research may also fall under FDA oversight and, as such, be required to follow PHS Policy.

Private accreditation.  An institution may choose to seek and maintain voluntary accreditation by a private agency, AAALAC, International (AAALAC). In the US, AAALAC accreditation depends on demonstrating compliance with the The Guide; thus, institutions that are not overseen by APHIS or OLAW may choose to be accredited and adopt the same standards for the care and treatment of research animals. Private accreditation for the care of captive animals is common across different kinds of facilities that house nonhuman animals, including those in research, but also in zoos and sanctuaries, who have their own accreditation organizations (e.g., American Zoological Association, AZA; Global Federation of Animal Sanctuaries, GFAS). Importantly, however, unlike oversight by a federal entity, voluntary accreditation does not provide a venue for public oversight and enforcement, nor does it allow for public transparency. For example, both USDA’s APHIS and PHS’s OLAW are responsive to public requests for investigation of facilities and records relating to oversight of those facilities. Private accreditation agencies do not provide public transparency of the accreditation process and/or inspection reports.

In Conclusion:

There are many sources of federal and local protection of animals in laboratories. Any research on AWA-covered species OR research that receives federal funding will be covered by federal laws aimed at ensuring laboratory animal welfare. Those laws provide for external oversight and for public transparency of records including, for example, inspection and investigation reports.

Most research is also covered by the IACUC system, which provides for oversight and, for many public institutions, another route of public transparency via state open records. Finally, many facilities– both public and private– maintain voluntary accreditation, which also should have a positive impact on animal welfare.

Speaking of Research

For more information about regulation, also see:

Update 5/24/16:  “New MOU Among NIH, USDA, and FDA.  NIH, USDA, and FDA have participated under a Memorandum of Understanding (MOU) Concerning Laboratory Animal Welfare for over 30 years. Each agency, operating under its own authority, has specific responsibilities for fostering proper animal care and welfare. This agreement sets forth a framework for reciprocal cooperation intended to enhance agency effectiveness while avoiding duplication of efforts in achieving required standards for the care and use of laboratory animals. The new MOU is available at: http://grants.nih.gov/grants/olaw/references/finalmou.htm.”

 

Guest Post: Why science needs to improve

Jeremy BailooToday’s guest post is from Jeremy D. Bailoo, PhD, a developmental psychobiologist in the Division of Animal Welfare at the University of Bern, Switzerland. He is currently involved in research which examines the manner by which we house and care for animals and its relevance to animal welfare and how it affects experimental results. He is particularly interested in providing empirically based procedures for refining animal housing.

Why science needs to improve

In a recent article in the Huffington Post, Professor Marc Bekoff and Dr. Hope Ferdowsian outlined their reasons for believing that science does not need mice. Their article was written in response to an editorial in the New York Times which advocated for the need for female mice in laboratory research. Bekoff and Ferdowsian made a number of interesting points and cited relevant supporting literature. However, their response presented only certain aspects of the issues involved. In this piece I will deconstruct the arguments levied by both sides. I will refrain from critiquing information that was not accompanied by a citation in either article, as these constitute unsubstantiated opinion.

The authors of the New York Times editorial described a new study published in the journal Nature Neuroscience which suggested “that research done on male animals may not hold up for women. Its authors reported that hypersensitivity to pain works differently in male and female mice….If these differences occur in mice, they may occur in humans too. This means a pain drug…might appear to work in male mice, but wouldn’t work on women.” These authors then state that failure to consider gender or sex in research is well recognized and cite the work of Zucker and Berry (2010) as well as the repositioning of interests statement of the National Institutes of Health (NIH) specifying sex as a biological variable in NIH funded research (see here and here).

The NYT editorial framed a well-articulated argument and did not overstate any of the claims that it made. The issue of the underrepresentation of females in biomedical research has been repeatedly highlighted (e.g., here, here, here, here and here) with little change in US science funders’ policy until now. It is important to note that nowhere in this article is it stated that all research in mice is ungeneralizable to females. Indeed, whether a scientific result is generalizable to both sexes is dependent on the phenomenon being studied; and this seems to be the case in particular for pain research in mice.

Mice in a research laboratory. Image courtesy of Understanding Animal Research.

Mice in a research laboratory. Image courtesy of Understanding Animal Research.

In their argument against the use of mice in research in the Huffington Post, Bekoff and Ferdowsian state that “numerous experiments on male and female non-human animals (animals) fail to reliably hold up in humans, and many prominent researchers have argued we need to develop non-animal models in order to learn more about serious diseases from which numerous humans suffer.” It is without question that some (not all) experiments in male and female rodents fail to replicate their results when that same experiment is performed on humans. However, as the ability to falsify and to replicate an experimental result are the cornerstones of the scientific method, failure to replicate an experimental result does not imply poor generalizability of an animal model to the human condition. I have recently co-authored an article on this topic demonstrating that meta-analytic studies have revealed that the reporting of criteria related to experimental design and conduct in some biomedical animal experiments is poor. The reasons why the result of an experiment conducted in non-human animals may fail to be replicated in humans is a consequence of complex processes that cannot and should not be trivially summarized by the statement “we need to develop non-animal models in order to learn more about serious diseases from which numerous humans suffer.”

In support of their argument, Bekoff and Ferdowsian cite the article “Mice Fall Short as Test Subjects for Some of Humans’ Deadly Ills”. In summarizing this article, Bekoff and Ferdowsian imply that because C57BL/6 mice (a single strain of 16 classified as Tier 1 in priority for investigation) do not seem to be able to model sepsis in humans, then all mice fail as a model of human disease. This is a logical fallacy, and a quick google search leads to very interesting responses to this article. Some are in favour of this piece (e.g., here) while others quickly identify flaws with the logic (e.g., here and here). Indeed, in the original article, the authors state “The study’s findings do not mean that mice are useless models for all human diseases.”

Next, Bekoff and Ferdowsian make the claim that the former director of the National Institutes of Health, Elias Zerhouni has lost confidence in the use of mice to model anything that is related to humans (see here). Bekoff and Ferdowsian fail to cite the clarification or perhaps are unaware of the clarification that was given (see here) in which Mr. Zerhouni states, “In short, animal models remain essential to the basic research that seeks to understand the complexities of disease mechanism.” As my colleagues at the website Speaking of Research have put it: “Animal models are essential to developing new medicines. They are, obviously, not sufficient on their own – cell cultures, human studies and computer models (among others) are also crucial methods used alongside animal models.”

The next paragraph with a citation states “Even experiments involving similar nonhuman species have shown that studies in mice, rats, and rabbits agree only a little more than half of the time (please see Hartung and Rovida 2009)”. Careful reading of this citation, however, does not yield this information. Indeed, nowhere in this article are any of these claims made. More interestingly, the cited article states, “no acceptable alternatives to reproductive-toxicity testing (in animals, my emphasis) have emerged, or are likely to be validated by 2018. Computational approaches are also limited by the complexity of reproductive toxicity and because half of the REACH chemicals are mixtures, inorganic, salts or contain metal atoms, rendering toxicity less predictable”. Thus, rather than supporting Bekoff and Ferdowsian’s arguments, it would seem that Hartung and Rovida advocate for the use of animals in toxicological research because there are no good alternatives.

mouse-sitting-on-red-mouse-house

Laboratory mouse. Photo courtesy of Understanding Animal Research.

Bekoff and Ferdowsian then state, “Attitudes toward animals are also changing, and now is the time for action. As per a recent nonpartisan Pew Research Poll, a solid 50 percent of people surveyed now oppose the use of animals in laboratory experimentation — an all-time high in the public opinion research literature.” This is indeed alarming and is the reason I have spent many hours researching these data. It is time that active scientists speak up for their science and break the cycle of misinformation that is spreading throughout our society.

In their penultimate paragraph Bekoff and Ferdowsian indicate that many may be incredulous in realizing “that mice and rats aren’t animals but a quote from the federal register does in fact read, “We are amending the Animal Welfare Act (AWA) regulations to reflect an amendment to the Act’s definition of the term animal. The Farm Security and Rural Investment Act of 2002 amended the definition of animal to specifically exclude birds, rats of the genus Rattus, and mice of the genus Mus, bred for use in research” (Vol. 69, no. 108, 4 June 2004).” It is worthwhile to note the date of this citation, June 2004 – 11 years ago. Much has changed in those 11 years and much will continue to change in the future. As science progresses, the type of animals used in research, the manner in which they are used, and their care will be continually scrutinized by scientists and the public. As a result, animal care, use, and corresponding regulations will continue to be adjusted. Moreover, animals used in research (including birds, rats, mice) are covered by Public Health Service (PHS) Policy on Humane Care and Use of Laboratory Animals since 1985 while guidelines for the care and use of laboratory animals have been critically considered since 1963 and have been continually updated as new information becomes available. Ferdowsian and Bekoff are either ignorant of current US regulations governing research or are deliberately being disingenuous.

These authors conclude that “there are numerous non-animal alternatives that are extremely reliable (please also see), and it’s about time they are used.” Again, where is the evidence for this? As I have outlined in this commentary, Bekoff and Ferdowsian have not provided sufficient evidence to come to this conclusion. Moreover, the statement that many non-animal alternatives are currently available and reliable requires careful deliberation. An example of such deliberation can be found here. The unsubstantiated statement that alternatives exist and are reliable does not make it so. Currently, such research and methods complement, rather than replace, research in non-human animals.

Thus, it would seem that the argument levied by Bekoff and Ferdowsian that science does not need research with mice is misleading. Poor reproducibility of experimental results is a problem in biomedical research. Indeed, it is a problem with science in general (e.g., here, here and here). To address the question “does science need mice”, one would have to: 1) examine the fields of science which use mice, 2) identify whether the science is performed with experimental rigour (design and conduct), and then 3) evaluate whether the findings obtained from these rigorous experiments are reproducible. By and large, the scientific community is still at step 2. As I mentioned previously, many fields which conduct research using mice report results that are irreproducible. The current cause ascribed to these failures is poor experimental design and conduct. This insight is gained by analysing whether information related to experimental design and conduct in published manuscripts and experimental applications are reported. For many fields of study employing the use of rodents, we cannot even begin to evaluate the effectiveness of a model because the manner in which the study was reported was poor. It is worth emphasizing that poor reporting of aspects of a study related to experimental design and conduct does not necessarily imply that a study was conducted poorly. Ascertaining this information would require interviews for each published article in question; a Herculean, if not impossible, feat. As highlighted in my recent paper, many solutions have been put forward to improve the manner in which we execute and report experiments but until these are endorsed and enforced, science in general will not improve. And that also applies to research using humans as subjects.

Jeremy D. Bailoo, Ph.D.

The opinions expressed here are my own and do not necessarily reflect the interests of the the University of Bern or the Division of Animal Welfare at the University of Bern.

Why mice may succeed in research when a single mouse falls short

The New York Times recently produced an article entitled “Mice Fall Short as Test Subjects for Humans’ Deadly Ills” which argued that certain mouse models were flawed. This post by Mark Wanner was originally posted on The Jackson Laboratory‘s “Genetics and Your Health” blog aimed to clear up some of the misunderstandings that may have come from this article, as well as to explain the benefits that can still be accrued from mice. It is being reproduced here with the full permission of the original author.

What would happen if all clothes were made to fit only one person, or at most, that person and his or her identical twin? Whoever it was, this one person wouldn’t represent all people. I hope this is an obvious statement—we all have differences in every measurement possible, and certainly no manufacturer would make a line of clothing tailored only to one person’s size.

But imagine taking this person and testing a new drug in her. Or him. Would you consider the drug fully tested for all people? No, it’s common sense that different people would respond differently, a concept borne out by the presence of side effects of varying severity for every significant pharmaceutical. But historically, that’s how most drugs have been selected for development until very late in the process. And that’s just one reason why it’s important to discuss the full story behind the recent New York Times article “Mice Fall Short as Test Subjects for Humans’ Deadly Ills.”

Let’s move past the sweeping generalization of the article’s title, which is belied by the fourth sentence anyway: “The study’s findings do not mean that mice are useless models for all human diseases.” The main point of the article is valid, which is that a recent study in the journal Proceedings of the National Academy of Sciences (PNAS) shows using mice for research into response to sepsis, burns and trauma (collectively called “shock”) has not translated into useful medicines for humans. In fact, the researchers showed that the genetic response to the narrow spectrum of maladies under discussion had very little correlation at all between mouse and human. For many scientists, this is very old news.

The NY Times article doesn’t address the fact that the studies it cites used the equivalent of one mouse—a single inbred strain, to be precise—to study the correlation (or the lack of correlation) between mouse outcomes and human outcomes in sepsis and shock. It is now well known that some inbred mouse strains, such as the C57BL/6J (B6 for short) strain used, are resistant to septic shock. Other strains, such as BALB and A/J, are much more susceptible, however. So use of a single strain will not provide representative results.

The strain in question, B6, is a reasonable starting point, but every B6 mouse is inbred to be an identical twin of any other B6 mouse. Characterizing the immune response in a single mouse strain is like doing so in a single person. Just like the analogy of the one-size clothing manufacturer, making a drug solely on the basis of one genetically isolated individual (especially a single mouse) is bound to fail. So it would have been far more accurate to use the title “A Single Mouse Falls Short” rather than “Mice Fall Short.”

Mouse used to treat deadly ills - Jackson Laboratory

Lenny Shultz, Ph.D., a professor and immunologist at The Jackson Laboratory who has made significant improvements to mouse models for human immune disease said, “. . . the mouse strain used in the study (C57BL/6) is representative of a single individual and doesn’t cover the diversity in the mouse population. Use of diversity outbred cross or collaborative cross mice would provide additional diversity.” The diversity outbred cross (as previously discussed in this blog) and collaborative cross mice are mouse populations specifically developed to provide wide genetic variability, and both have been developed mainly within the past decade. Possibly, if this diversity outbred resource was used, an appropriate range of results more representative of human outcomes may have emerged.

Elissa Chesler, Ph.D., a behavioral genomicist at The Jackson Laboratory, further commented: “For behavior and many other biomedically relevant fields we can’t simply generalize from “MOUSE” to “HUMAN”–we must ask which mice, and which human. Most studies involving mice are restricted to a small handful of strains. New genetic and genomic methods enable us to ask this question with improved efficiency and effectiveness. Learning how to grapple with genetic diversity and delivering experimental systems that make this genetic diversity readily accessible to those working on disease therapeutics is critical to improving the success rate of preclinical research.” Thus, genetic diversity should be accounted for in future pre-clinical tests, and researchers need to pay greater attention to selecting the right model system to mimic human disease.

Now, largely through Lenny Shultz’s efforts, mice are also available that can host human cells. These so-called “humanized mice” have recently improved greatly in effectiveness and use, as Shultz himself documented in a recent Nature Reviews Immunology review. They are very useful for immune response studies, partly for the very reasons documented by the PNAS study authors—mouse and human immune responses differ. Engrafting human immune tissue into an experimental mouse system provides a much better platform for translational research: it tests a real human immune system in a whole organism rather than in a test tube. Therefore the mouse remains a pivotal model system for the human condition.

Such improvement comes on top of the mouse’s already highly significant legacy, of course. I recently wrote about the work of George Snell, whose groundbreaking immunological research in mice led to the discovery of the major histocompatibility complex and, ultimately, successful organ transplants. A recent success is the multiple sclerosis therapeutic BG-12, which underwent testing in mice before showing dramatic success in clinical trials. The compound is still under review by the FDA, but approval is highly anticipated.

There has been some thoughtful coverage of both the PNAS study and the NY Times article in publications such as The Scientist and Science News. Both publications speak mostly to those who are already scientifically inclined, however. It would be good to see more nuance in mainstream media outlets. It seems like there’s little middle ground between “hope for cure” articles from model organism studies that minimize the translational difficulties and “research debunked” articles like the current NY Times example. But in reality, almost all studies live in that middle ground.

Medical progress is hard-won, and few studies contribute directly to improvements in the clinic. But research adds to knowledge, some of which will eventually help doctors and their patients. Without it, we’ll have to live with the status quo, something very few will choose to accept. So read between the lines and learn about the roots of our medical “breakthroughs.” Chances are they started a while ago—in a mouse.

Mark Wanner
The Jackson Laboratory

Why do we use Genetically Modified animals?

This excellent 3 minute video, produced by Understanding Animal Research, shows how the use of genetically modified animals can benefit modern medicine – in this instance, to create a method of screening for certain bacteria.

We look forward to more videos from UAR.

p.s. please give the video a “thumbs up” so that it can spread far and wide and improve people’s understanding of animal research.