"The ability to empathize with others stems from a long evolutionary history that includes empathy-like behaviors in animals beyond humans. Whales and primates grieve alongside members of their social groups, for example, while rodents are able to recognize and respond to the fear and pain of their neighbors." —Amanda Heidt
"Mice may ‘catch’ each other’s pain—and pain relief: After an hour of mingling, healthy mice mirror a companion’s pain or morphine-induced relief." —Carolyn Wilke
“Pain isn’t just a physical experience...It’s an emotional experience as well." —Stanford University neuroscientist Dr. Monique Smith
Anyone who's studied or interacted with mice knows they're remarkably adaptive and emotional beings. When I lived in the mountains outside of Boulder, Colorado, I used to love to watch them scooting inside and outside of my home. I also wondered what they were feeling—if they displayed empathy and shared feelings of joy when they played—they do indeed actively play with one another—or felt the pain or fear of other mice. Over the years I learned they do.1,2 So, the title of a recent study by Stanford University neuroscientist Dr. Monique Smith and her colleagues called "Anterior cingulate inputs to nucleus accumbens control the social transfer of pain and analgesia" attracted my attention.3
I'd seen a reference to this essay a few weeks ago, but not until I read Carolyn Wilke's "Mice may ‘catch’ each other’s pain — and pain relief" about this research did I know the study focused on mice. In this piece Dr. Smith is quoted as saying, “Pain isn’t just a physical experience...It’s an emotional experience as well." This also caught my attention and nicely summarizes their own and others' research. What also came to mind was that the United States Federal Animal Welfare Act (AWA) still maintains that mice, rats, and other bona fide animals are not animals despite the indisputable biological fact that they are.
The researchers conducted their study to learn more about the neural mechanisms underlying murine pain, fear, and relief and concluded, "We established that mice rapidly adopt the sensory-affective state of a social partner, regardless of the valance of the information (that is, pain, fear, or pain relief)."3 And, the neural circuits that are involved are similar to those of humans, strongly suggesting "a shared evolutionary basis for empathy in humans and mice."
All well and good, except for the mice who were involved. Every single discussion I could find about this study focused on how the results might be used to help humans with social personality disorders, without a single word about how what was learned could benefit the mice who clearly are deeply feeling sentient rodents.
Concerning the ludicrous decision not to recognize mice and other nonhuman animals as "animals" in the AWA, when skeptics tell me that I'm not telling the truth or surely have misread something, I simply refer them to the USDA website where we read:
"Enacted January 23, 2002, Title X, Subtitle D of the Farm Security and Rural Investment Act, changed the definition of 'animal' in the Animal Welfare Act, specifically excluding birds, rats of the genus Rattus, and mice of the genus Mus, bred for use in research." (my emphasis)
It's a fact that these rodents and some other bona fide animals have been redefined as non-animals. Two researchers told me it's clear they've been written off because of their widespread use and because they make a lot of money for those who wantonly breed and use them in all sorts of research.
I often wonder where are all the scientists who know that rats and mice are sentient animal beings and why aren't they protesting the idiocy of the AWA? How do they and the USDA get away with this sham? Why aren't they demanding a revision that correctly classifies mice, rats, and other "non-animals" as the animals they truly are? After all, they laud and often exaggerate the utility of what they themselves call "animal models" of human disease using mice and rats. I honestly can't get out of this whirlwind no matter how hard I've tried and no matter how many researchers I've talked to.
Where to from here?
"The environment a laboratory animal lives in can have a dramatic impact on whether it’s a good model for human disease." —David Grimm
"Our myopic focus strictly on animals living inside impoverished cage environments imposes huge societal costs. In many instances, we are studying biological processes that likely occur only inside a cage. Despite decades of animal research, scientists have made very few inroads to treatments for psychiatric illness, or even treatments of other human ailments." —Dr. Garet Lahvis
I've been told by some researchers who wish to remain anonymous that they think the AWA's position must be revised immediately. One researcher told me she frankly didn't think it would make any difference in how research is conducted, and, with a smile, she added, "It would at least show that people who work on the AWA know some biology." Another said, "It's the dumbest thing I've ever seen." One well-known scientist told me, "I've tried with absolutely no success to get the AWA revised to reflect that mice and other animals are real animals. It's just too frustrating to get anything done on this."4 After I posted this piece I learned of an essay called "Should the AWA Cover Rats, Mice, and Birds? The Results of an IACUC Survey" in which Drs. Scott Plous and Hal Herzog present data showing "...a majority of individual animal researchers favor the inclusion of rats, mice, and birds under the AWA."
Current research clearly shows that numerous nonhumans have rich and deep emotional lives and I look forward to these data—including some that are decades old—playing a significant role in rewriting and expanding research guidelines and laws and placing mice and other animals back in the animal kingdom. Bridging the knowledge translation gap and using what we know is essential not only to protect animals used in research but also for informing future research. The AWA ruse clearly shows that we still have a long way to go.
To sum up, while I'm advocating for protecting mice and other animals used in invasive research, I'm also advocating for using what we know to guide research projects, for implementing welfare standards based on reality, and for getting more scientists to speak out about the misclassification of mice and other animals.
These moves will make for more humane research and generate more reliable data. It's a win-win situation that's long overdue.
References
Notes
1) For more information on play in mice, rats, and other rodents click here.
2) In "Empathic behavior according to the state of others in mice" we're told, "When the conspecific mice were in a painful state, subject mice showed preferential approach behavior toward them, presumably recognizing the state. Both visual information and olfactory information are indispensable for this empathic behavior." In "Research Shows Mice May Have Feelings, Too" there's a similar claim: "Scientists find evidence that mice and humans may share some sophisticated emotional characteristics. It's now thought mice have the ability to be affected by another mouse's pain or suffering. Also see "Even mice show empathy for each other" and for more information click here.
3) A summary of their study reads, "In mice, both pain and fear can be transferred by short social contact from one animal to a bystander. Neurons in a brain region called the anterior cingulate cortex in the bystander animal mediate these transfers. However, the specific anterior cingulate projections involved in such empathy-related behaviors are unknown. Smith et al. found that projections from the anterior cingulate cortex to the nucleus accumbens are necessary for the social transfer of pain in mice (see the Perspective by Klein and Gogolla). Fear, however, was mediated by projections from the anterior cingulate cortex to the basolateral amygdala. Interestingly, in animals with pain, analgesia can also be transferred socially. You can read more about this study here.
4) Some scientists, such as Drs. Gahret Lahvis and John Gluck, have gone public on these and other concerns.
Bekoff, Marc. The Animal Welfare Act Claims Rats and Mice Are Not Animals.
_____. Do Uncaged Animals Produce More Reliable Science? (An interview with Garet Lahvis about his innovative ideas for animal research.)
_____. Voracious Science: A Journey from Animal User to Advocate. (John Gluck's new book details his transformation from researcher to protector.)
_____. How to Make Studies of Animal Behavior More Reliable.
______. Animal Emotions, Animal Sentience, and Why They Matter.
_____. Mice, and Perhaps Canines and Other Animals, Can Track Time.
_____. Mice Aren't Furry Little People: Sloppy Science Fails Humans.
_____. Rats vs. Mice in Research: Were We "More Humane" Years Ago?
_____. Men's Odor Stresses Mice and Rats Used in Pain Research.
Grimm, David. Swapping a cage for a barn: Can lab animals be studied in the wild? Science, June 21, 2018. (An interview with Dr. Garet Lahvis "about what studying lab animals in the wild could look like, and why some researchers think it won’t happen." See also Do Uncaged Animals Produce More Reliable Science?)
Lahvis, Garet. Primate researchers need to explore alternative methods. The Hill.
Plous, Scott and Hal Herzog. Should the AWA Cover Rats, Mice, and Birds? The Results of an IACUC Survey. Lab Animal 28, 38-40, 1999.
