How does progesterone stop swelling in the brain?
The skull is actually a fixed box. If you add any volume to a fixed space, what happens? There’s pressure, and that pressure causes damage to the neurons and the blood vessels. Progesterone rebuilds the blood-brain barrier so when ions and water particles want to go across, they can’t. There’s another way it works. If you bump your elbow and get a big bruise, your body makes more skin and muscle tissue. That’s caused by cytokines that signal to the body, there’s an injury here, send in the cleaners. Macrophages come in and clean up—they take a bottle of chemical, pour it all on the floor, and start sweeping it up. That’s OK if it’s your elbow, or even your heart. But tiny damage to certain areas of the brain is devastating. So when a macrophage [called a microglia in the brain] starts spilling its chemical to clean up, the problem is it’s spilling it indiscriminately and it’s killing neurons and pathways all around it that were working. The progesterone stops cytokine production. How d
