Early and late phase of degeneration (IMAGE) Rice University Caption Based on thousands of experiments over more than a decade, Rice University biochemists Michael Stern and James McNew believe degenerative diseases as varied as Alzheimer's, Parkinson's and muscle atrophy occur in two phases (green and red) marked by distinct alterations in the activity of the signaling pathway proteins TOR, AMPK, Foxo and JNK. In the early phase (left), autophagy is suppressed, which increases oxidative stress, eventually bringing about the late phase (right) in which autophagy is restored, causing rapid degeneration. Credit Illustration courtesy of Michael Stern/Rice University Usage Restrictions Must credit "Michael Stern/Rice University" License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.