Notes from Headstrong by Dave Asprey
How Your Neurons Can Perform Better
As you know, all cells have a membrane made primarily of fat, but myelin is a special, thicker fat layer that is essential for your brain to function; without it, the signals between neurons would simply be lost.
We are born with very little myelin, and the process of producing it (called myelination or myelinogenesis) occurs rapidly during infancy. This is the main reason babies develop so quickly from adorable little lumps to walking and talking humans. On the opposite end of the spectrum, demyelination, or the loss of myelin along the cells; axons, is responsible for many neurodegenerative diseases, such as multiple sclerosis.
Researchers have learned a lot about how myelin is created (and destroyed) by studying patients with MS. While the majority of us are unlikely to develop MS, we can all benefit from this research by looking at the methods doctors are using to treat neurodegeneration. It takes a lot more work to restore failed myelin than it does to keep yours strong, but the methodology is the same.
A type of brain cell called oligodendroglia does the work to form your myelin. Throughout adulthood these cells constantly generate new myelin and replace segments of myelin that break. Just as the electric company maintains power lines to ensure smooth signals across a network, so, too, do these specialized cells conduct myelin maintenance throughout your neural networks. And your maintenance worker cells rely on a proper balance of hormones – particularly thyroid hormones and progesterone – to do their job well.
Research shows that thyroid hormones are also crucial for the health and survival of oligodendroglia cells and therefore for the constant rebuilding of healthy myelin. This is one more reason to stay on top of your thyroid health and get your levels checked once a year or more often if you are feeling tired a lot.
Researchers have found that the hormone progesterone signals oligodendroglia to initiate the process of demyelinating neurons. In one study, mice that were treated with progesterone had more oligodendroglia that were able to repair more myelin.