Thread by @soniashah

The Case for Free-Range Lab Mice

🧵 A thread based on my @NewYorker story🧵

newyorker.com/culture/annals…

No-one knows how many mice & rats are experimented on in the US, bc even tho' they are the most common species used in biomedicine, thanks to Sen. Jesse Helms, rodents are officially excluded from the Animal Welfare Act.

It’s estimated @ 120 million/yr.

tinyurl.com/47awxv4s

Experiments on animals are required by law and bioethics codes, but in a 2014 analysis of 2,000+ drugs, animal tests were found to be “highly inconsistent” predictors of toxic effects in humans.

You might as well toss a coin instead.

journals.sagepub.com/doi/abs/10.117…

“A mouse is not a person” as the joke goes

newyorker.com/magazine/2022/…

But it’s not just species differences that accounts for the disconnect. In a recent study, identical experiments on identical mice conducted in three separate labs rendered completely different results

#replicationcrisis

journals.plos.org/plosbiology/ar….

Most lab mice haven’t seen the sun in 100s of generations. They typically are inbred through at least 20 generations of brother-sister matings, reared in sterile conditions & spend their lives in shoebox-sized cages.

@GLahvis explains the impact here

tinyurl.com/yt3yynr3

Although individuality drives evolution itself, the idea that animals could be made uniform--"like the litmus paper of the vitamin chemist”–caught on in the early 20th cent. The idea was to transform the idiosyncratic animal into a tech commodity: a “pure unit” of life.

In a 1949 feature on some of this work, Life magazine pronounced the research possibilities “virtually limitless.”

books.google.com/books?id=IkkEA…

Critics of this reductive, mechanistic view of animals were dismissed as pathological. There was even a psychiatric condition known as “zoophil-psychosis” to explain it.

See "Passion for Animals Really a Disease," NYT, March 8, 1909

Scientists won dozens of Nobel prizes conducting experiments on standardized lab animals. But individuality persisted, as did idiosyncratic responses to subtleties in the lab environment, even among supposedly uniform animals bred for experimentation.

nature.com/articles/laban…

.@JeffreyMogil, e.g, found that lab mice will express different “pain behaviors” if there’s a human male nearby–or even a t-shirt worn by a man

They’re as aware of us as we are of them

nature.com/articles/nmeth…

This paper provides an excellent overview
bmcbiol.biomedcentral.com/articles/10.11…

Some scientists are developing new ways to predict human biological responses, e.g by using 3D organoids grown from human stem cells as experimental subjects instead of lab animals.

One brain organoid recently learned to play the video game “Pong"

bbc.com/news/science-e…

Others are experimenting with exposing lab animals to the wild. Letting them free-range in barns or in outdoor enclosures as below, where they can interact with each other & the environment how they like

"Go where the wild things are," -@Grahammunology, tinyurl.com/ynd995ux

Unlatching the cage gives lab mice lives that are more like our own. That makes for less stressed animals–and better science.

But it could also mean accepting animal agency as a limiting factor in science--a historic reversal!

“I imagined lab mice that had dug into the soft earth, tunnelled under the metal fenceposts, and slipped into the woods. They took their data with them, and were lost to science forever.”

Read the story: newyorker.com/culture/annals…

#labanimals #experimentation #rewilding