From: J. R. Molloy (jr@shasta.com)
Date: Sun Sep 23 2001 - 12:33:58 MDT
Forget what you thought:
Memory about to change, fast
http://news.bmn.com/news/story?day=010921&story=1
by Rabiya S. Tuma, BioMedNet News
Researchers have been slowly developing an image of how humans establish
memories, but that pace will likely accelerate this fall, with new work from
Susumu Tonegawa's lab. A groundbreaking study released today is just the first
of several due to appear in coming months.
Using standard approaches, but with an elegance not always achieved in
experimental design, Tonegawa's lab is set to unveil results illuminating how
short-term memories are turned into long-term ones via a process called
consolidation, how different types of learning occurs in unexpected ways, and
how memory recall occurs.
The work is extremely important, says Alcino Silva, an associate professor of
neurobiology at the University of California-Los Angeles. He says he knows the
work intimately through discussions with Tonegawa. "Many of the studies before
did not bridge what this study does," he told BioMedNet News in a telephone
interview.
In his view, and in Tonegawa's as well, what stands out in this work is the
ability to connect what is happening at different levels of physiology, from
molecular pathways to cells, to cell circuits, and finally to behavior.
In each of the studies, the first of which is published in today's issue of
Cell, the researchers combine the relatively new technology of transgenic mice
with older techniques like electrophysiology and behavioral studies.
Significantly, in each study the transgenic animals carry conditional
knock-out mutations, so that only the part of the brain under study is
altered. The rest of the animal is unaffected, which helps to minimize
confounding effects.
"This new thrust, this new approach is flourishing," said Tonegawa today.
"Before, people could not do this. The method of studying the underlying
mechanism for memory was rather restricted. People studied learning and memory
at certain levels of complexity: psychologists studied behavior,
pharmacologists studied the effect of drugs on behaviors..."
But this approach in combination with the more traditional ones allows
scientists to connect the levels, and that is what makes it so powerful.
For example, in today's Cell paper Tonegawa's group shows that
calcium/calmodulin-dependent protein kinase IV (CaMKIV) is required for the
consolidation of short-term memories into long-term stable ones. Previously,
there was evidence that protein kinase A (PKA) was involved in the process,
but with the new data, it is clear that "they work hand-in-hand," said
Tonegawa. And perhaps most importantly, he says, they can distinguish what is
happening at these different levels of complexity when CaMKIV is missing from
the forebrain.
The current study involves memories which are learned by repeated exposure,
like one might learn a piece of music. But a second study, which will be out
later this fall in Cell, describes how memories from a one-time event, such as
when one meets a friend for a special dinner, are established. Finally,
Tonegawa says the third body of work, which has been discussed at scientific
meetings but which he declined to discuss until it is in press, involves the
mechanism of memory recall.
"This will be a very exciting period in the next two years," predicted
Tonegawa. "The field of learning and memory will advance very fast."
--- --- --- --- ---
Useless hypotheses, etc.:
consciousness, phlogiston, philosophy, vitalism, mind, free will, qualia,
analog computing, cultural relativism, GAC, Cyc, Eliza, cryonics, individual
uniqueness, ego, human values, scientific relinquishment
We won't move into a better future until we debunk religiosity, the most
regressive force now operating in society.
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