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BIOLOGY
 European researchers uncover memory’s chemical ingredients
European specialists have uncovered the chemical mix responsible
for memory through the observation of genetically modified
mice. Memory is such an inherent part of life that it is easy
to forget that it can be boiled down to a mere chemical reaction.
And now for the first time, researchers from the European
Molecular Biology Laboratory have created an innovative model
to detect the chemical processes behind memory. They focused
their research on the hippocampus region of the brain, an
area integral to memory formation, and the proteins and receptors
responsible for receiving and interpreting sensory stimuli.
They recently reported their findings in Learning and
Memory.
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hippocampus region of the brain is critical to
memory and spatial navigation. |
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Researchers from the European Molecular Biology Laboratory’s
(EMBL) Mouse Biology Unit in Monterotondo, Italy, and the Universidad
Pablo de Olavide in Sevilla, Spain, decided that to best understand
memory one must first understand the components involved. They
therefore focused their research on the sensory regions of the
brain. They were able to create mice lacking some links in the
memory process to help them identify which stages are critical
in creating a memory.
Each cell in our body receives a constant flow of stimuli from
our environment, and those stimuli the cell has already experienced
are stronger and longer each time allowing the cell to distinguish
it from new, unrecognised information. This phenomenon, known
as long-term potentiation (LTP), has long been suspected of
being the basis for learning and memory, though the chemical
mechanics behind it have never been fully understood.
“It is difficult to study a dynamic process like memory
in the test tube,” says Liliana Minichiello, whose group
carried out the study at EMBL’s Mouse Biology Unit. “To
assess if the molecular mechanisms that generate LTP also underpin
memory formation you need to study a living animal while it
is learning.”
Minichiello and her team used molecular, electrophysiological and behavioural methods to develop their novel mouse model. Their multidisciplinary approach has given them the opportunity to establish the molecular basis of LTP while simultaneously addressing its effects on learning and memory.
To better understand LTP, they created mice with a defective
receptor found in the hippocampus called TrkB. These mice lacked
the ability to activate a signalling pathway involving the protein
PLCg, and as a result were unable to learn. Additionally, the
hippocampal cells were unable to produce LTP, leading researchers
to believe that the mice were unable to recognise familiar stimuli.
“TrkB and the PLCg activated signalling pathway are central
to both LTP and learning. For the first time we have been able
to prove that LTP and learning do in fact have a common molecular
basis,” says José Delgado-García from the
University of Sevilla.
The researchers are continuing their research trying to further
define TrkB’s role in learning and memory. Their discoveries
in mice have significant bearing on our understanding of human
memory as the underlying molecular pathways are likely very
similar between species.
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More information:
EMBL homepage
Multidisciplinary functional genomics
Learning and Memory
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