Another interesting (at least to me) article.
Jeff Nagelbush
[EMAIL PROTECTED]
Ferris State University
Cage life may drive lab animals so insane
that experiments are invalid
James Meek
Guardian
Tuesday August 28, 2001
It is a scientist's reward: after feeding a laboratory mouse an
untried medicine, or turning it into a cocaine addict, or flashing
lights at it, the rodent appears to get smarter, or slower, or more
discerning. Do it a hundred times, and you have got a research
paper - or a billion-pound drug.
But what if the mouse, in the bleak, confined circumstances of
its laboratory cage, has gone quietly insane before the
experiment even begins?
That is the possibility being raised by US scientists who say
they have found evidence that the sheer boredom of life as a
captive lab animal may be enough to incur brain damage.
If true, it would call into question the validity of many
experiments, particularly in behavioural research where
scientists draw conclusions based on changes in the ability of
rodents to carry out tasks.
Joseph Garner, a behavioural scientist at the University of
California, in Davis, told a conference earlier this month that was
evidence that a type of repetitive behaviour called stereotypies,
common in caged animals, was caused by brain damage. In
humans, stereotypies - rhythmic, involuntary actions or repetitive
limb movements - are believed to be linked to damage in a part
of the brain called the basal ganglia. Similar behaviour in lab
animals has up until now been thought of as superficial tics in
normal animals.
But when Dr Garner applied a test for basal ganglia damage to
caged parrots, he found that the birds with a characteristic brain
damaged response were the same birds which displayed
stereotypies such as feather plucking. He is now applying the
test to mice.
The journal Nature, which reported on Dr Garner's work in a
recent issue, recalled that stereotypies in lab rodents were only
discovered in 1996 when a Swiss researcher used an infra red
camera to find out what mice got up to when their keepers
switched off the lights and went home.
In the darkness, the mice began an obsessive ritual of bar biting
and cage scratching - classic stereotypies.
Underlining the possible link between the dull sameness of cage
life and mouse madness, the journal pointed out that studies
last year showed making life more interesting for lab animals, by
allowing mice and rats to socialise with siblings for instance,
made the creatures' brains bigger.
"I think it sounds reasonable," said Nick Neave, a behavioural
psychologist at the University of Northumbria. "We've known for
many years that if you give animals plenty of stimulation in a lab
environment they behave differently from animals in a bare cage.
I think it does raise some very important issues, not just
ethically but scientifically, where scientists are saying 'well, this
means so and so', when it may not be so clear cut."
The Home Office code of practice recommends that breeders
and suppliers of lab rodents give a single mouse 200sq cm of
cage space, and a single rat 500-800sq cm. The Home Office
also recommends "cage enrichment" for "environmental
complexity". But this is not compulsory.
Science or fiction?
Work with lab animals, particularly mice and rats, is a staple of
scientific research. Here are the findings of three recent reports
from the thousands published each year:
o In an attempt to show the effects of junk food on the brain,
Canadian scientists fed one group of young rats on fatty food for
12 weeks, with another group being put on a low fat diet. They
were then given a memory test involving pressing a lever. The
junk food rats were more forgetful. Conclusion: junk food is bad
for the memory.
o Scientists in the US monitored the brain activity of rats while
they ran round a circular track to get food and then later while
they slept. During their slumber, the same brain cells fired as
when they were running. Conclusion: rats dream.
o A New Jersey mouse, called Doogie, with a single added gene
was able to whiz through mazes and learn from experience
significantly better than its non-transgenic peers. Conclusion:
one day it may be possible to tinker with human genes to make
people cleverer.
Guardian Unlimited © Guardian Newspapers Limited 2001
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