Researchers May Have Discovered How Memories Are Encoded In the Brain 185
Zothecula writes "While it's generally accepted that memories are stored somewhere, somehow in our brains, the exact process has never been entirely understood. Strengthened synaptic connections between neurons definitely have something to do with it, although the synaptic membranes involved are constantly degrading and being replaced – this seems to be somewhat at odds with the fact that some memories can last for a person's lifetime. Now, a team of scientists believe that they may have figured out what's going on. Their findings could have huge implications for the treatment of diseases such as Alzheimer's."
Re:Fuck GizMag (Score:5, Informative)
If you want to read something intelligent about "memory storage theory", here's [brown.edu] a better article--from Brown University, November 14, 2006.
Pull-quote:
PROVIDENCE, R.I. -- Daily events are minted into memories in the hippocampus, one of the oldest parts of the brain. For long-term storage, scientists believe that memories move to the neocortex, or "new bark," the gray matter covering the hippocampus. This transfer process occurs during sleep, especially during deep, dreamless sleep.
Important work, but clearly being oversold (Score:5, Informative)
"Now, a team of scientists believe that they may have figured out what's going on. Their findings could have huge implications for the treatment of diseases such as Alzheimer's."
This statement is utterly absurd, but the authors of the PLoS article appear to have done some important work here. I'm not a physicist and can't evaluate the quality of the modeling and measurement, but assuming that is all legitimate (and I have no reason to doubt it), then their findings could prove useful to furthering theories on memory formation and stability. Basically they found a series of potential mechanisms by which activated CAMKII (via synaptic activity) can interface with microtubules to update their phosphorylation states. In what I would consider heavy speculation, they suggest that these phosphorylation states, along with the structural and electrostatic properties of microtubules, can produce and modulate information processing along/within the microtubules.
Keeping Occam's Razor in mind, to me it would be simpler if these interactions simply increase or decrease microtubule stability, and possibly affect shape to promote dendritic bifurcation versus elongation or retraction. Not to say some kind of information processing can't be happening in the microtubules, but we already have some pretty good theories regarding information processing in dendrites based on membrane voltage propagation. With changes in microtubule phosphorylation state there is also the possibility of making cross-linking tighter or looser, making it possible to fit in more or fewer microtubules and change a dendrite's diameter. All of these changes are important for signal processing, but by impacting the propagation properties of the membrane rather than through the microtubules directly. I base these comments on other research that have found changes in dendrite morphology and physiology concurrent with synaptic plasticity. One must always keep in mind though that anything as complex as memory is going to rely on multiple mechanisms. Any claim that "the mechanism for X" has been found is always hyperbole.
I would say that some of that speculation, as well as the fact that this is all highly theoretical (no experimental work) are the major reasons this wasn't published in a journal like Nature or Science. Still PLoS Computational Biology often has some very good and important articles.
Better article (Score:5, Informative)
http://medicalxpress.com/news/2012-03-memories-encoded-brains.html [medicalxpress.com]
Q&A with the researcher. Bit more detail than GizMag.
http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002421 [ploscompbiol.org]
The paper (gizmag links to it too)
Bad Title (Score:5, Informative)
What they've actually proposed is a mechanism for how memories are stored, not how they're encoded. The question is, how can memories be so stable if they're made up of synaptic connections that are constantly changing? These authors have proposed an answer, a molecular description of a much more stable link between two neurons that could form and then remain fixed for years. If they're right, it's a very important advance. But encoding is a completely different question: how does a particular memory get represented as a set of those connections. This work says nothing about that.
To give an analogy, they've described the magnetic domains on a hard disk. They haven't described how JPEG transforms images into patterns of bits.