Scientists
Improve Memory in Mice by Turning off Brain Enzyme
By: Unknown Author
Canadian Press, August 28, 2002
Scientists have boosted learning and memory in
mice by blocking a brain enzyme, and they say the result could point to
therapy for reducing forgetfulness in older people. They said the work
implicates the enzyme, called PP1, as a key actor in the brain's system
for erasing memories.
Other scientists said it's unclear if the findings
may lead to memory-enhancing therapies for older people, but they called
the work important.
"This is going to make us think in new and
different ways about forgetting," said James McGaugh, director of the
Center for the Neurobiology of Learning and Memory at the University of
California, Irvine.
"It says here we have a molecule in the brain
that is constantly making us forget, and when you block that, it slows
down the forgetting."
The research is reported in Thursday's issue of the
journal Nature by a team led by Isabelle Mansuy of the Swiss Federal
Institute of Technology in Zurich, Switzerland.
The enzyme was thought to play some role in erasing
memories, but its precise job wasn't clear, she said.
The researchers genetically modified mice so they
could block PP1 simply by giving the animals food laced with a particular
drug.
They found that mice in which PP1 was inhibited did
better on learning and memory tests than other mice did. The animals were
tested on whether they remembered seeing particular objects and whether
they could recall the location of an escape platform submerged in a tank
of opaque water.
Aged mice also did better when PP1 was suppressed,
hinting at a possible approach to treating age-related memory loss, Mansuy
said.
"This indicates that in the aged brain the
molecular machinery is not completely deteriorated and that these
functions can be restored if only one component - PP1 - is blocked,"
she said.
Dr. Eric Kandel, a Columbia University professor who
shared the 2000 Nobel Prize for medicine for his work on the nature of
learning and memory, said the research is an important step in science's
understanding of the brain's constraints on long-term memory formation.
"This shows that if you remove these constraints
you enhance the memory storage," he said. "The fact that this is
also operative in older mice of course only enhances this work."
In a second Nature study bearing on brain biology,
researchers in Scotland presented evidence that a gene variant linked to
Alzheimer's disease might also impair mental abilities in people without
the illness. Some prior studies had already suggested that.
They studied 466 people who'd taken a mental ability
test at age 11 and again at age 80. Of the group, 121 carried the APOE E4
gene variant, which raises the risk of getting Alzheimer's.
Nobody in the new study had Alzheimer's or any other
dementia. But while the test scores of the gene carriers and non-carriers
were about the same at age 11, the average scores of the carriers were
slightly lower at age 80.
FAIR USE NOTICE: This
page contains copyrighted material the use of which has not been
specifically authorized by the copyright owner. Global Action on Aging
distributes this material without profit to those who have expressed a
prior interest in receiving the included information for research and
educational purposes. We believe this constitutes a fair use of any such
copyrighted material as provided for in 17 U.S.C § 107. If you wish to
use copyrighted material from this site for purposes of your own that go
beyond fair use, you must obtain permission from the copyright owner.
|
