Introducing the brain: connectivity patterns (Introduction)

by David Turell , Thursday, January 18, 2024, 19:23 (100 days ago) @ David Turell

Not a large number:

https://www.sciencedaily.com/releases/2024/01/240117143741.htm

"A new study by physicists and neuroscientists from the University of Chicago, Harvard and Yale describes how connectivity among neurons comes about through general principles of networking and self-organization, rather than the biological features of an individual organism.

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"'You don't expect it to work as well when you dig into the minutiae, but when we did that here, it ended up explaining things in a way that was really satisfying."

"Understanding how neurons connect

"Neurons form an intricate web of connections between synapses to communicate and interact with each other.

"While the vast number of connections may seem random, networks of brain cells tend to be dominated by a small number of connections that are much stronger than most.

"This "heavy-tailed" distribution of connections (so-called because of the way it looks when plotted on a graph) forms the backbone of circuitry that allows organisms to think, learn, communicate and move.

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"To understand how neurons form connections to one another, they developed a model based on Hebbian dynamics, a term coined by Canadian psychologist Donald Hebb in 1949 that essentially says, "neurons that fire together, wire together." This means the more two neurons activate together, the stronger their connection becomes.

"Across the board, the researchers found these Hebbian dynamics produce "heavy-tailed" connection strengths just like they saw in the different organisms.

"The results indicate that this kind of organization arises from general principles of networking, rather than something specific to the biology of fruit flies, mice, or worms.

"The model also provided an unexpected explanation for another networking phenomenon called clustering, which describes the tendency of cells to link with other cells via connections they share."

Comment: a good designer sets up simple patterns to repeat. It means all neurons follow the same developmental rules throughout evolution..