Dietary acetyl-L-carnitine improves spatial behaviour of old rats.

Acetyl-L-carnitine was given to aging rats to determine the extent to which it changed age-related impairments in several different behaviours. One group of rats was given acetyl-L-carnitine, 80 mg/day, beginning at 16 months of age. A second group of rats was housed and treated identically, except that no drug was administered. At 22 months of age, both groups of rats began a series of behavioural tests, along with a group of young rats, four months of age. The tests included: place learning on a circular platform, probe reversal of place learning on a circular platform, two choice simultaneous spatial discrimination in the stem of a T-maze spatial alternation in the arms of a T-maze, and sensory-motor behaviour (initiation of walking, turning in an alley, walking on a square, round, and rectangular bridge, turning on an inclined grid, holding on to a wire, light-dark preference). The tasks varied in their sensitivity to age-related impairments. These data indicate that long-term therapy with acetyl-L-carnitine attenuates certain age-related cognitive deficits and may have a beneficial effect on longevity.