Researchers at Max Planck, Rockefeller, and Duke Universities examined the connections in brain tissue from the visual cortex, the first stop for information coming in from the retina. It was a tall order. A news item from Max Planck, “No cable spaghetti in the brain,” describes the cabling nightmare:
Nerve cells in the human brain are densely interconnected and form a seemingly impenetrable meshwork. A cubic millimeter of brain tissue contains several kilometers of wires. A fraction of this wiring might be governed by random mechanisms, because random networks could at least theoretically process information very well. Let us consider the visual system: In the retina, several million nerve cells provide information for more than 100 Million cells in the visual cortex. The visual cortex is one of the first regions of the brain to process visual information. In this brain area, various features as spatial orientation, color and size of visual stimuli are processed and represented.
Not Spaghetti Cables
But they did not find randomness. They found a well-organized structure like a library.
David Coppedge, “Brain Neurons Are “Comparable to a Library”” at Evolution News and Science Today (April 8, 2022)
Here’s the Max Planck news item (November 23, 2015).
The more we study, the more complex it gets. Consider:
Our neurons’ electrical synapses are the dark matter of the brain. These aren’t the familiar chemical synapses but a second set, the electrical synapses that enable currents to travel directly between neurons from pore to pore. A recent study in fruit flies shows that without the little-understood electrical synapses, neurons’ reaction is much weaker and some of them became unstable.
Memory leans more on the brain’s electric field than on neurons. MIT researchers compare the electric field to an orchestra conducting the neurons as players. The neurons associated with our memories may change; it’s the electric field that holds the memories together, the neuroscientists say.
and
The brain unfolds like a drama, with neurons in different roles. Researchers studying fruit flies hope that spotting the stages at which human neurons go missing or wrong can help develop treatments to insert or replace them. Human and fruit fly brains are strikingly similar but with vastly different results. Clearly, the brain is not all we need to know about a life form.