The 100 billion neurons in your head have interconnected into a vastly complex network, and these connections can change and evolve as you “think” and “learn.” Exactly how this network architecture is developed and even how individual connections are selected is not yet clear.
However, researchers from the Max Planck Institute for Neurobiology have experimentally verified that neurons have an even more efficient method for quickly selecting “good” connections from “maybe-not-so-good” connections, even before the critical synapse–the chemical controller that regulates communication between neurons–is fully developed.
The discovery shows that as an extension of a neuron (either a dendrite or axon) comes into contact with another neuron, a flood of calcium ions exchanges with the pair of cells and if certain thresholds are reached, then the growing connection will stick around long enough for a synapse to form; otherwise, it will retract and wiggle about growing into another direction.
The biological growth technique is observed to be quite efficient with “decision-making” for forming connections, in particular because synapse development can take much longer to complete. Even though the following article loosely suggests that this network connection technique “enables thinking,” it’s not necessarily the case that each time we have a “thought” that we are actually making a new, physical connection. Neural “learning” likely requires an evolution in the network structure, but our notion of “thinking” is likely related more to the patterns of electrical behavior in the existing network.
This work is also quite important for the future development of neurotechnological devices. For a pure neuron device to connect directly with a human brain, it will be required to have neurons living on the implanted device to grow extensions and interconnect directly with the subject brain… so, an understanding of how these connections develop and select one another will be absolutely vital for successful devices.
So, check out the following articles, and we’ll be following the important developments.
“Efficient technique enables thinking” :: PhysOrg.com :: August 19, 2008 :: [ READ ]