Effects of dimethylaminoethanol upon life-span and behavior of aged Japanese quail.

The lysosome hypothesis of aging predicts that membrane stabilizers will extend life-span. Stabilizers containing the dimethylaminoethanol moiety (DMAE) have been reported to extend the life-span of drosophila and mice. We tested the prediction in Japanese quail (N = 15) by administering DMAE bitartrate (18.4 mg/kg/day) in the drinking water for 69 weeks, starting at 195 weeks of age. A matched control group (N = 14) received tartaric acid (4.0 mg/kg/day) in the water. Contrary to the prediction, the DMAE-treated group has a shorter life-span after start of treatment (49 weeks) than the controls (69 weeks). No significant differences between the groups were observed in body weight or daily fluid intake. Three behavioral studies were carried out on survivors at 243-249 weeks of age, namely; activity response to light-flash; sexual mounting response to a female quail; and classical conditioning of the heart rate. Aged quail differed from young-adults in changes in motor activity in response to light flashes. Aged quail appeared less responsive initially to reinforced conditioning trials and demonstrated extinction when light flash was not followed by electric shock. There were no detectable differences in latency to mount or in basal heart rate, either as a function of age or as a function of DMAE treatment.