Brain 10 Times More Active Than Previously Thought
Scientists' understanding on how the human brain works could take a revolutionary turn. Researchers from the University of California, Los Angeles suggests that people's brains are 10 times more active than previously thought.
This change of perspective could lead to new approaches in treating neurological disorders, as well as in developing computers with algorithms that can have a better grasp of the human understanding.
The study was published, March 9, in the journal Science.
The Brain, 10 Times More Active
The study was focused on the function and structure of dendrites, which are compounds of neurons. Neurons also contain soma, which is an entity that generates short electrical pulses called "spikes" in the attempt to interconnect neurons.
Until this study, researchers used to believe that dendrites are activated by the somatic spikes, the resulting activity being the core of how memories are created and stored.
However, the team of researchers pointed out that dendrites are not just passive conduits of the somatic spikes, as they are electrically active in animals who move around freely. This type of physical activity was found to generate up to 10 times more spikes than somas.
This finding could revolutionize the way scientists approach the spikes in the soma, which are the main way in which memory, perception, and learning take place.
More than 90 percent of the neural tissue consists of dendrites. According to Mayank Mehta, the senior author of the research, knowing that dendrites are much more active compared to soma significantly changes the scientists' perspective on how brain processes information.
What the new research proved is that dendrites generate their own spikes, instead of just being a transmitter, which occurs 10 times more often than somas. Additionally, dendrites also cause large fluctuations in voltage. Up until now, it was believed that the spikes work in a binary way: the types of events created were either all or nothing. However, the dendrites were found to generate varying voltages, some of which were even bigger than the spikes. This type of activity suggests that dendrites have the capacity to carry out an analog-like computation.
"Parietal dendritic action potentials and dendritic membrane potentials exhibited egocentric spatial maps comparable to pyramidal neurons. These results have important implications for neural coding and plasticity," noted the study.
Using this new approach, the researchers analyzed the activity of dendrites for up to four days in rats. The animals were allowed to move in a large maze, freely. The measurements taken from the brain area responsible for movement planning, the posterior parietal cortex, suggests that the dendrites are far more active than the somas.
Human Capacity To Memorize, Equal To The Entire Internet
Prior to this research, another study carried out on the brain activity suggested that our memory capacity is 10 times higher than previously thought, equaling the capacity of the entire internet. The researchers observed that synapses can vary in size.
Their increments can be as small as 8 percent, which suggests that there are 26 categories of synapse sizes rather than just a few as it was previously thought. This approach changed the perspective in the field of neuroscience, proving that the human brain is capable of remembering significantly more content.