Changes in auditory brainstem responses in alpha-linolenic acid deficiency as a function of age in rats.

Auditory brainstem responses (ABRs) to click stimuli have been compared in young (21-day-old), adult (6-month-old), and old (18-month-old) rats fed a normal (Arachid-Colza) or an alpha-linolenic acid deficient (Arachid only) diet. Wave I amplitude and latency did not show any significant change with either age or diet. However, wave III showed a progressive decrease in amplitude and latency from young to adult and from adult to old rats having a normal diet. With alpha-linolenic acid deficiency, wave III amplitude and latency values decreased faster than in the normal diet control groups. Although final values in the old groups with the two diets were similar, with alpha-linolenic acid deficiency values for wave III decreased to this final level in the adult group. These data indicate that the central auditory nervous system ages faster, or earlier, with a fatty acid deficiency.