quarta-feira, 6 de maio de 2009

Memória e gordura

Post de Sérgio Arruda

Você está se esquecendo de alguma coisa... que tal pensar no que você está comendo. Veja artigo, cópia do blog da Nature e reportagem no Telegraph sobre a importância da gordura (produto do metabolismo de gordura- OEA) para a memória.

“Mmm… chocolate”. Remember who said that? It was Homer Simpson. Why do you remember? Maybe it’s because that utterance inspired you to eat some lovely, unctuous, fatty chocolate, which boosted your memory.

For ‘tis written: scientists from the University of California, Irvine, have shown that the molecule oleoylethanolamide (OEA), which is released when fat gets to the gut, can help rats to retain memories after they’ve been through a training exercise. The study came out this week in the Proceedings of the National Academy of Sciences.

The experiments involved giving rats OEA, then checking their ability remember during two exercises – navigating a maze and avoiding something nasty.

Having lots of OEA normally quashes the appetite, tricking the brain into thinking its stomach is full. But this compound also seems to help consolidate memories, reporter John von Radowitz in The Scotsman. (Scotland of course famous for its high-fat cuisine in the guise of deep-fried battered chocolate bars.)

The process might have evolved many years back in our history, the authors suggest.

“Remembering the location and context of a fatty meal was probably an important survival mechanism for early humans,” author Daniele Piomelli told BBC News.

The Daily Telegraph tells us that a memory pill to help “students and Alzheimer’s patients” is on the cards. Whether that is the case or not right now, the work could lead to new therapeutics for people with memory or other cognitive problems, the authors suggest.


Memory pill that could help students and Alzheimer's patients being developed

A pill that could make memories "stick" is being developed by scientists in a study that could help students revising for exams and patients with brain disorders such as Alzheimer's disease.

By Richard Alleyne, Science Correspondent
Last Updated: 11:12PM BST 27 Apr 2009


A pill that could make memories 'stick' is being developed by scientists in a study that could help students revising for exams and patients with brain disorders Photo: GETTY

Researchers, looking into obesity, discovered that fatty foods not only send feelings of fullness to the brain but they also trigger a process that consolidates long term memories.

It believed that this is an evolutionary tool that enabled our distant ancestors to remember where rich sources of food were located.

Now they hope to develop drugs which mimic the effect of fat rich foods in order to boost memory in those suffering from brain disorders or who need to cement facts in their brain.

The team at the University of California found that oleic acids from fats are transformed into a compound called oleoylethanolamide (OEA) in the upper region of the small intestine.

OEA not only send hunger-curbing messages to the brain to increase feelings of fullness but also "causes memory consolidation, the process by which superficial, short-term memories are transformed into meaningful, long-term ones", it was discovered.

Professor Daniele Piomelli, who led the study, said it works by activating memory-enhancing signals in the amygdala, the part of the brain involved in the consolidation of memories of emotional events.

Professor Piomelli said: "OEA is part of the molecular glue that makes memories stick.

"By helping mammals remember where and when they have eaten a fatty meal, OEA's memory-enhancing activity seems to have been an important evolutionary tool for early humans and other mammals."

He added that dietary fats are important for overall health, helping with the absorption of vitamins and the protection of vital organs.

While the human diet is now rich in fats, this was not the case for early humans, he said. In fact, fat-rich foods in nature are quite rare.

"Remembering the location and context of a fatty meal was probably an important survival mechanism for early humans," he said. "It makes sense that mammals have this capability."

The researchers, who published their results in the Proceedings of the National Academy of Sciences, found that administering OEA to rodents improved memory retention in two different tests.

When cell receptors activated by OEA were blocked, memory retention effects decreased.

Prof Piomelli said drugs that mimic OEA are in clinical trials.

Rebecca Wood, Chief Executive of the Alzheimer's Research Trust said the research offered "fascinating" insights into the way we remember.

"When thinking about what constitutes a healthy diet, usually what's good for the heart is also good for the head.

"Better understanding of how memories are formed could lead to new treatments that help the brain when it becomes affected by Alzheimer's."

Copia do Blog da Nature

Artigo publicado no PNAS.

Reportagem no Telegraph


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