MPNforum Magazine

The Mouse and the Itch.

We function as much by censoring information as processing it. Maybe more.

For example, long consideration of the plight of refugee Syrian families living in tents or cobbled together shelters on scrabbly desert, at the mercy of weather, predators, attack could be paralyzing.   It isn’t simply because we don’t let it occupy our field of attention too long.

Much of the global horror, man-made or natural, is at most a faint backdrop to our workaday concerns.

So far beneath our awareness as to rarely generate a thought is the laboratory mouse.  Bred to standardized perfection, the mouse is our basic biological testing machine, permitting easy experimentation and inter-laboratory replication of findings.  With no possibility of wrongful death actions or lawsuits of any kind.

So when the Guardian published a piece on the pain-itch phenomenon

I wasn’t surprised to learn the theory of transmission from primary sensory neurons entering the spinal cord’s dorsal horn to the motor neurons carrying the message of pain was tested in the white mouse.

In simple terms, we produced a mouse with a genetic modification that allowed us to trace and manipulate a cellular function. We then killed off this modification and injected the mouse with a lethal diphtheria toxin.  A lousy day for the mouse by any standard.  Now here comes the chilling clinical report:

“As a result, the mice became hypersensitive to mechanical, hot and cold stimuli, and to the itching induced by the injection of histamine or chloroquine, as measured by the amount of time they spent licking and biting the affected area of skin “

So, for the researchers to discover a spinal gateway to pain this mouse was deprived of its natural resistance, genetically modified, injected with toxins, subjected to heat, cold and other painful stimuli and suffered uncontrollable itching in response to further injections… until it was killed and autopsied.

All this may help alleviate human suffering down the road but the least we can do is consider now and then our fellow mammals, the little rodents that unwillingly suffer pain, itch and death for our sake.

And, given the opportunity, support rigorous institutional program oversight and the work of the NIH Office of Laboratory Animal Welfare.

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