A few months ago, I reported on an exciting finding that rapamycin, a drug currently used in transplant patients, improved memory in Alzheimer's mice. Now a different strain of mice (ones engineered to have defects in the genes that make amyloid precursor protein) has also shown improvements in learning and memory, correlated with less damage in brain tissue, after rapamycin treatment lowered levels of amyloid-beta-42. The mice given the drug performed at levels comparable with normal mice.
Reference:
[190]
(2010). Inhibition of mTOR by Rapamycin Abolishes Cognitive Deficits and Reduces Amyloid-β Levels in a Mouse Model of Alzheimer's Disease.
PLoS ONE. 5(4), e9979 - e9979.