This seems to be the main paper.
Feeding acetyl-L-carnitine and lipoic acid to old rats significantly improves metabolic function while decreasing oxidative stress
Dr. Ames founded a company based on the ALA/ALC age reversal finding - juvenon
This paper has microscope photos of the differences in brain cells (scroll down)
Another paper by Ames on ALC/ALA w/r Cognition
Another Ames paper
Non Ames paper that confirms the findings.
Life Extension® Interview with Dr. Bruce Ames