Alzheimer's disease brain extract stimulates the survival of cerebral cortical neurons from neonatal rats.

Cell cultures of neonatal rat cerebral cortex in a serum-free medium were used to investigate a lack of neuronotrophic factors in Alzheimer's disease (AD) brain. A few neurons survived in the absence of brain extract. The addition of normal brain extract resulted in a 2.5-fold increase in neuronal survival. AD brain extract contained 4-fold neuronotrophic activity of normal brain extract. These findings are in contrary to the previous hypothesis of a lacking neuronotrophic factors in AD brain. These new results may change the concept of mechanism of neuronal death in AD.