Introducing the brain: protecting memories of learned info (Introduction)

by David Turell , Monday, February 10, 2020, 20:04 (1535 days ago) @ David Turell

Takes lots of myelin production:

https://medicalxpress.com/news/2020-02-long-term-requires-nerve-insulation.html:

"'We find that a single, brief fear-learning experience can cause long-term changes in myelination and associated neurophysiological changes within the brain that can be detected even a month later,"

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"Myelin is formed during early development by brain cells called oligodendrocytes, which wrap themselves hundreds of times around the branching axons emanating from certain key neurons. This forms a thick sheath of protein and fat that acts like an insulator around an electrical cable, strengthening and speeding electrical signaling in the nerve pathways that connect one neuron to the next.

"This insulation is particularly important for the brain's busiest information superhighways, like the high-speed nerve fibers that can extend three feet or more, giving your brain nearly instant command over your body's muscles. Damage to this myelin and an associated loss of muscle control are hallmarks of MS, but comparatively little attention has been given to the possibility that myelin could also undergo dynamic changes in the healthy adult brain.

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"Scientists have known for decades that learning depends initially on the brain's ability to rewire itself by forming new connections between neurons. These new studies represent growing evidence that myelin's ability to reinforce and maintain these new connections may determine what makes certain memories stick.

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"To test whether this new myelin was required for the animals to learn, the researchers repeated the experiment with mice genetically engineered to be unable to form new myelin. These mice initially froze in the conditioning chamber, but unlike normal mice their fear appeared to fade away after about a month. The researchers concluded that new myelin formation is not needed for initial learning, but plays a specific role in the consolidation and maintenance of long-lasting fear memories.

"Because myelin acts to increase the speed and efficiency of signals passing along axons, changes in myelination may influence important electrical signaling patterns within neural networks. In their new study the researchers discovered that losing the ability to form new myelin produced long-term changes in the activity of neurons in the mouse prefrontal cortex.

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"'We are now seeing that the process of oligodendrocyte generation and myelination can be quite dynamic in the normal adult brain. It's a form of plasticity that responds to experience and that causes long-lasting changes. This is a very recent concept that we are in the early days of exploring.'"

Comment: Note the last quote which indicates how quickly the brain protects its new learning. The brain is carefully designed in its plasticity and in its methods of protecting memories which help all animals learn to live safely.