Infant Rat Heads Grafted Onto Adults' Rat Thighs!

All I can say that this is consistent with the fine quality of sceintific
research we have come to expect from New Scientist and affiliated
publications.

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INFANT RAT HEADS GRAFTED ONTO ADULTS' THIGHS
By Emma Young
New Scientist
Tuesday, December 3, 2002
 
http://www.newscientist.com/news/news.jsp?id=ns99993135
 
Infant rats are being decapitated and their heads grafted onto the thighs of
adults by researchers in Japan.

If kept cool while the blood flow is stopped, a transplanted brain can
develop as normal for at least three weeks, and the mouth of the head will
move, as if it is trying to drink milk, the team reports.

The grafted heads could be "excellent models" for investigating brain
function in human babies after periods of no blood flow, known as ischemia,
they claim.

"Our main purpose is to investigate how the transplanted brain can develop
and maintain function after prolonged total brain ischemia," researcher
Nobufumi Kawai, at the Jichi Medical School in Tochigi, told New Scientist.
"And we tried to investigate the effect of lowering the temperature of the
brain during the grafting."

But other researchers are far from convinced by the grisly technique. Denis
Azzopardi of Imperial College London, UK, who investigates brain injury in
newborn babies, says many well-characterised animal models of studying brain
ischemia already exist.

Public concern

"These are well established models for testing different degrees of ischemia
and potential treatments. And there are plenty of studies showing
experimentally that cooling during ischemia can be neuroprotective,"
Azzopardi says. "So I'm not sure that this complicated technique offers an
advantage in any way -- I can't see it being widely used."

Vivisection that provides no obvious research benefit and involves clear
animal suffering will only cause public concern, adds a spokeswoman for the
UK's Research Defence Society, which advocates responsible animal
experimentation.

"Regulations in the UK are much stricter than in Japan. If expert opinion
says there are better or other ways of doing an experiment that would cause
less animal suffering, it wouldn't be licensed," she told New Scientist.

Temperature sensitive

The Japanese team removed heads from 12-day-old rats and waited 90 minutes
before connecting them to the blood supply in the thigh of an adult rat
recipient. "The grafted brain appeared to develop normally provided the
operation was done at the low temperature of 19°C," says Kawai. But in
operations conducted at 29°C, still well below body temperature, the brain
was severely damaged.

In contrast, the standard animal models for studying human infant ischemia
involve, for example, tying the carotid artery in rats. This halts blood
flow to the brain.

About one in 500 babies suffer from a lack of oxygen during birth. This can
happen if the placenta, which supplies blood from the mother, becomes
detached, or a blockage forms. Azzopardi is part of a team investigating
whether cooling immediately after birth can reduce subsequent brain damage.

Previous work, largely in animals, has shown that cooling after brain injury
reduces damage by suppressing inflammation, for example.

Early results from the Japanese research are published in Neuroscience
Letters (vol 325, p 37).