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July 2003 Discover Magazine asks
"Can We Trust Research Done with Lab Mice?"

From: Karen Dawn
Subject: DawnWatch: Discover Magazine asks, " Can We Trust Research Done with Lab Mice?"
Date: Sun, 22 Jun 2003 09:31:52 -0700

The July, 2003 edition of Discover Magazine includes a story, beginning on page 64, headed, "Can We Trust Research Done with Lab Mice? New studies show that animals used in critical experiments may be out of their minds." It is written by Barry Yeoman. The opening paragraph is included on the Discover website:

"In the early 1990s, a soft-spoken doctoral candidate at Switzerland's leading university asked a deceptively simple question: What do all those laboratory mice do after the researchers and technicians go home for the night? It wasn't a frivolous query. In a typical animal research lab, most rodents' lives are spent in shoebox-size enclosures containing food, water, bedding, and nothing else, all stacked from the floor to the ceiling on uniform steel racks. Hanno Würbel, the young animal behaviorist who asked the question, knew that mice living in such barren housing often develop bizarre behaviors, such as turning endless backward somersaults. But because mice are nocturnal animals, most scientists are asleep when the critters are active."

The rest of the article may be available on line once the July issue is no longer on news stands. I will give a brief summary and some quotes below but recommend that those interested in this field pick up the magazine -- the article is lengthy and fascinating.

Wurbel set up a video camera:

"When he reviewed the videotape, Wurbel saw something reminiscent of home movies made at a psychiatric hospital. In the dark, the mice performed the same useless tasks repeatedly, with such a compulsive persistence that Wurbel couldn't help but think something had gone awry in their brains. In one sequence, a mouse climbs the stainless steel walls of its cage, hangs from the ceiling by its forelegs while gnawing on the bars, then drops to the floor, only to repeat the process endlessly. On the other side of the cage, a second mouse performs backflips, one per second for up to 30 minutes at a time. Animal behaviorists refer to highly regimented repetitive activities with no apparent purpose as stereotypies. Some of Wurbel's mice exhibited stereotypic behaviors for half of their waking hours."

The stereotypies seem to start out as functional activities, trying to escape the cage, for example, but soon morph into ritualized behaviors.

Wurbel has concluded that much research relies on brain damaged subjects and therefore could lack validity.

We read that a clean cage with nothing else has been the international norm; unless they are studying the effects of enrichment versus impoverishment, most scientists see no reason for changing that. However, Yeoman points to studies conducted back in the 1950's by Mark Rosenweig at Berkeley, which found that animals' enzyme levels were affected by their environments.

Regarding the effect on biomedical testing:

"In the 47 years since Rosenweig reported his pioneering work, scientists have come up with more anecdotal evidence that keeping animals under different conditions can dramatically alter research outcomes. For example, lead-contaminated drinking water damages the brains of impoverished mice but not the enriched ones. Rats can tolerate 60 times more uranium if they're allowed time to acclimate to new cages, and even dim light in the lab at night speeds up tumor growth by inhibiting production of the hormone melatonin."

Fifty years seems a long time to have this sort of information without acting on it. But scientists whose grant incomes are not directly affected by the validity of their experiments are reluctant to admit that psychological damage affects outcome. Wurbel, however, says,

"The point that the environment might change behavior but it doesn't change biology is ridiculous. Every behavior has a physiological background."

Wurbel would like to see:

"a time where we will have natural-like, although heavily managed, populations of rats or mice, maybe in big enclosures, representing whole populations."

The article follows this point and ends with an interesting quote from Würbel:

"But you know what the problem is with this? If we get to the stage where we think we need to treat the animals this way, experimenting on them will probably become impossible -- because that would mean they would almost achieve the same status that we have."

I worry that the article gives the impression that mouse madness is the only factor making their use scientifically unsound. Those interested in the range of factors which make animal testing an increasingly outdated form of study will find extensive information on the topic at:

Nor will more interesting environments solve the ethical issues.

Yet, the article is a positive step, as it calls into question the validity of laboratory experiments, and also because it portrays laboratory animal suffering in a way that is unusual in the mainstream media. It makes it clear that anesthesia and painkillers (both shockingly under-used) do not solve the animal welfare issues.

Yeoman's article stresses scientific validity; he states that it is of greater concern than the also important issue of animal welfare. However, immediately following Yeoman's article is one by David Berreby headed "Saving Private Squeaky." Berreby notes that different rats, who appear identical, will have radically different rates of learning, and behave differently in experimental situations. His article refers to the "reward" he realized a group of rats with whom he was doing maze work were going to get for their efforts - euthanization. It focuses on his choice to save his favorite, the smartest, but one realizes that the rat's less favored cage-mates fared badly. The article is touching, and a nice balance to Yeoman's piece which concentrates almost exclusively on science.

The two excellent articles open the door for letters to the editor on related issues that were not addressed. One issue is the scientific validity of testing on rodents, regardless of their living conditions. Another is the question of our right as a species to do as we please with those of other species, just because we can. Publications are generally far more likely to publish positive letters, but one can make one's points in the context of an appreciative letter to the editor.

Discover takes letters at:

Always include your full name, address, and day time telephone number when writing a letter to the editor.

Yours and the animals',
Karen Dawn

DawnWatch is an animal advocacy media watch that looks at animal issues in the media and facilitates one-click responses to the relevant media outlets. You can learn more about it at To subscribe to DawnWatch, email and tell me you'd like to receive alerts. If at any time you find DawnWatch is not for you, just let me know via email and I'll take you off the subscriber list immediately. If you forward or reprint DawnWatch alerts, please do so unedited, leaving DawnWatch in the title and including this tag line.