Long-term acetyl-L-carnitine preserves spatial learning in the senescent rat.

1. Untreated rats of different ages and old rats chronically treated with Acetyl-1-carnitine were subjected to the spatial learning task. 2. For this test, a circular pool filled with milk-opacified water was used. The animals were to reach an escape platform with the aid of visible environmental cues. 3. The experimental results indicated a clear-cut deterioration of the old animal's acquisition ability of a spatial learning task. 4. The long-term treatment (8 months) with Acetyl-1-carnitine was found to antagonize such a deterioration.