Allopregnanolone, a metabolite of the hormone progesterone that is made in the central nervous system, reversed neurological decline and improved performance on memory tests in 3-month-old mice with characteristics of Alzheimer's disease, a recent study showed. Allopregnanolone can increase the number of neural progenitor cells of mice and humans in vitro. In this study, led by researchers at the University of California, Los Angeles, the same molecule was given in vivo to triple transgenic Alzheimer's disease mice and to normal mice to test its effect on learning and memory. Allopregnanolone was found to regenerate nerve cells significantly in a part of the hippocampus—a region of the brain important to memory—in the transgenic mice but not in the normal mice. The Alzheimer's mice not only improved their performance on a trace eye-blink conditioning test of learning and memory, but performed as well as did the normal mice.
Allopregnanolone can reverse cognitive deficits in an Alzheimer's mouse model, perhaps by helping certain nerve cells proliferate and thrive, the authors concluded. The findings, they say, suggest further investigation of allopregnanolone for its therapeutic potential in Alzheimer's disease.
Wang, J.M., et al. Allopregnanolone reverses neurogenic and cognitive deficits in mouse model of Alzheimer's disease. Proceedings of the National Academy of Sciences USA. 2010. 107(14):6498-503. (PDF, 690K)