Fig. 8.

Aging was associated with increased reactive oxygen species formation and lipid peroxidation, coupled with a decrease in membrane arachidonic acid. Untetanized dentate gyri from 4- and 22-month-old rats were dissected at the end of the period of electrophysiological recording, stored as described in Materials and Methods, and analyzed for reactive oxygen species production, lipid peroxidation, and membrane arachidonic acid concentration. Reactive oxygen species production and lipid peroxidation were significantly increased in 22-month-old compared with 4-month-old rats (p < 0.05 and p < 0.01, respectively, Student’s t test). Mean arachidonic acid concentration was significantly decreased in 22-month-old compared with 4-month-old rats (p < 0.01, Student’st test). The number of observations is given inparentheses.