An animal study published in the Journal of Neuroscience suggests that the pregnancy hormone prolactin spontaneously increases myelin, thus enhancing signaling within the nervous system, and help repair damage in the brain and spinal cord. This indicates that the hormone may have potential as a therapeutic for treating multiple sclerosis, an autoimmune disease characterized by loss of myelin protecting the nerve fibers of the central nervous system.

Comparing pregnant and virgin female mice of the same age, Weiss's team counted hundreds of cells in their brains and spinal cords. They found that the pregnant mice had twice as many myelin-producing cells, called oligodendrocytes, and continued to generate new ones during pregnancy. After giving birth, these mice also had 50 percent more myelin coating their nerve cells.

The researchers also showed that pregnancy repaired nerve cells faster where the myelin had been chemically destroyed: Pregnant female mice had twice as much new myelin two weeks after damage. Finally, they found that prolactin mimicked the effects of pregnancy, increasing both myelin production and repair. This suggests prolactin, which increases during pregnancy, may help induce the making of new myelin.

Further tests would have to be conducted to verify the effect of prolactin in animal models of MS, and if results are promising human clinical trials may be conducted.

Source: SFN