Biology

Why our brains may be 100 times more powerful than believed

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The dendrites in our brain have been underestimated for 60 years says a new study
A neuron with the dendrites shown in green
Shelly Halpain/UC San Diego
The dendrites in our brain have been underestimated for 60 years says a new study

A new study out of the University of California Los Angeles (UCLA) has found that one part of the neurons in our brains is more active than previously revealed. The finding implies that our brains are both analog and digital computers and could lead to better ways to treat neurological disorders.

The focus of the study was the dendrites, long branch-like structures that attach to a roundish body called the soma to form neurons. It was previously believed that dendrites were nothing more than conduits that sent spikes of electrical activity generated in the soma to other neurons. But the study has shown that the dendrites themselves are highly active, sending spikes of their own at a rate 10 times that previously believed.

The finding runs counter to the long-held belief that somatic spikes were the main way we learn and form memories and perceptions.

"Dendrites make up more than 90 percent of neural tissue," said UCLA neurophysicist Mayank Mehta, the study's senior author. "Knowing they are much more active than the soma fundamentally changes the nature of our understanding of how the brain computes information. It may pave the way for understanding and treating neurological disorders, and for developing brain-like computers."

The researchers also found that unlike the spikes of electrical activity generated by the somas, the dendrites could put out longer-lasting voltages that in their sum total were actually more powerful than the somatic spikes. They say the spikes are like digital computing in that they are all-or-nothing events, while the dendritic flows are akin to analog computing.

"We found that dendrites are hybrids that do both analog and digital computations, which are therefore fundamentally different from purely digital computers, but somewhat similar to quantum computers that are analog," said Mehta. "A fundamental belief in neuroscience has been that neurons are digital devices. They either generate a spike or not. These results show that the dendrites do not behave purely like a digital device. Dendrites do generate digital, all-or-none spikes, but they also show large analog fluctuations that are not all or none. This is a major departure from what neuroscientists have believed for about 60 years."

Mehta adds that the fact that dendrites are about 100 times larger in volume than somas, it's possible that our brains have 100 times more capacity to compute information than previously believed.

A neuron with the dendrites shown in green
Shelly Halpain/UC San Diego

In making their discovery, the UCLA team was able to implant electrodes in the brains of rats that went next to dendrites. This was a departure from previous work where the sensors went straight into the dendrites, killing them and making their activity impossible to measure. They found that the dendrites were five times more active than the somas when the rats were sleeping, and 10 times more active when they were awake and moving about.

The discovery shows that learning likely takes place with more flexibility than previously believed.

"Many prior models assume that learning occurs when the cell bodies of two neurons are active at the same time," said Jason Moore, a UCLA postdoctoral researcher and the study's first author. "Our findings indicate that learning may take place when the input neuron is active at the same time that a dendrite is active — and it could be that different parts of dendrites will be active at different times, which would suggest a lot more flexibility in how learning can occur within a single neuron."

"Due to technological difficulties, research in brain function has largely focused on the cell body," added Mehta. "But we have discovered the secret lives of neurons, especially in the extensive neuronal branches. Our results substantially change our understanding of how neurons compute."

The research has been published in the journal Science.

Source: UCLA

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11 comments
psiclone
Doesn't mean anything if we're 100 times less likely to use them.
Bob Flint
You know the saying mind over matter......well we first need to believe, then tap into the source and use it.
If you don't use it then you loose it, if you can't find it then you either never had it, or you never thought it was there in the first place.
guzmanchinky
My brain feels dumber after reading that article knowing how smart scientists are that study these things... :)
LarryWolf
Yeah but except for those like Einstein few of us ever use more than 1% of our brains.
JasonCornish
I am reading a lot of assumptions and conjecture in this article that are not supported by the evidence. There is no data to suggest that this is anything more than a coincidental finding. Nothing to tell us what the significance of this finding is. There is a neat and unexpected finding and then a lot of guessing and jumping to conclusions as to what it means. It may mean. It may mean nothing. Further research is needed but it was interesting. Here is a postulation for you: This constant low-level activity is simply needed for maintenance of the neural connections and if the level drops too low the neural connection severs and looks for somewhere else to connect. My hypothesis is just as valid as any made in this article given that I am highly educated and trained in the bio, psych, and medical fields.
CraigAllenCorson
I have often thought that some sort of analog computer would be far more flexible and powerful than a digital computer could ever hope to be. Nice to learn, even at this late date, that I was right. Larry Wolf - That is a very common misconception. Every one of us uses 100% of our brains, just not all at once. Different parts are active during different tasks, but any part that was never used would simply wither and die, quite early in life.
over_there
Jason has a really good point . I've noticed alot of articles make things sound like a breakthrough but if you actually read the facts they read "scientist's still have no idea but have a good story to tell"
GeorgeWade
Some of us were already using MindMapping tech years ago and beginning to enjoy enhanced brain power. There are other techs: like lightning reading; de Bono Think; SuperMemo or clones; that can work together for some of us — while most of us have our favourites.
¿ I would imagine that there is at least a gain of 10 X there for dedicated users !
judahis
I too have studied neurology, at Columbia University, and as a freshman was taught by the man who elucidated neuronal functions by studying squid axons, etc. So, any new knowledge will lead to new understanding, and these findings about dendrites, which challenge long held assumptions, should have profound impact, methinks.
ThomasMandile
One one-trillionth part of the infinite intellect is infinite, as is a trillionth of that. Theoretically, each individual human mind can catalog, contain, comprehend, and understand everything in the entire universe, limited and impeded only by the limits of our five senses, and mortality.