In fruitflies, age-related memory impairment (AMI) is accompanied by decreased brain polyamine levels. Gupta et al. found that olfactory learning was enhanced either by feeding the polyamine spermidine to aged flies or by inducing the expression of spermidine specifically in Kenyon cells (neurons essential for olfactory memory). Spermidine administration increased levels of autophagy in aged flies, and genetic disruption of autophagy caused loss of the memory-promoting effects of spermidine, suggesting that autophagy is functionally required for polyamine-mediated protection from AMI.