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Memory Molecules Morphing

posted Mar 22, 2014, 9:16 PM by Ellen Pearlman

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The little white dots are chemical memory beads forming in spiny looking neuron dendrites

Scientists at Albert Einstein College of Medicine at Yeshiva University in New York have been able to show the molecular basis of memory using fluorescent tagged neurons of mice. Neurons are “extremely sensitive to any kind of disruption” and seriously difficult to track.  The scientists tagged something called messenger RNA (mRNA)  made up of beta-actin protein. MRNA’s, a family of RNA, copy DNA’s genetic information and translate it into proteins. 

The researchers stimulated neurons in the mouse’s hippocampus, an area of the brain where memories are made, at least for mice. They “watched fluorescently glowing beta-actin mRNA molecules form in the nuclei of neurons and travel within dendrites, the neuron’s branched projections.”

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Neurons meet at synapses spines, which resemble fingers grasping one another. Beta-actin protein strengthens the synaptic connections by altering the shape of the dendrite spines. Memories happen when lasting synaptic connections form between dendrites. It seems beta-actin is an active compound and assembles and disassembles quickly. 

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Michaengelo’s interpretation from the Sistene Chapel ceiling of the fingers of the hand of God and Adam reaching out to touch each other

Apparently neurons are smart and cost effective well behaved worker bees. Dr. Robert Singer, one of the research scientists said according to the work of Adina Buxbaum, the post doctoral researcher who worked on this project. "After the mRNA molecules make beta-actin protein for just a few minutes, they suddenly repackage and …. become masked. In other words, the default condition for mRNA in neurons is to be packaged and inaccessible." Apparently they turn that default behaviour off when making memories and temporarily unmask.

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MRNA neurons - masked, and unmasked

The paper on B-Actin RNA and its translations was published in Science Magazine as was the second paper on visualization of mRNA.

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Marcel Proust, the man in question

Of course this does not answer why the whiff of baked bread can trigger a Marcel Proust “Remembrance of Things Past" moment for some and not for others. From what I could see in the medical video, the memory molecules went up and down the spiny dendrite like beads tipping back and forth in a straw. It would be amazing to know what they stored. Was it an image? What kind of image? Or sound? Or feeling? Or smell? Of course this was mice, not people, but its still an important question.

In terms of arts practice, a lot of the soul searching goes around issues of memory. Could memory eventually be wiped out or replaced like in the movie “Eternal Sunshine of the Spotless Mind?” How about substituting someone else’s memory for yours, or vice versa? Seems like something that could be replicated in the not so distant future - at least for mice.

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