Brain acetylcholine synthesis declines with senescence.

The synthesis of whole brain acetylcholine is reduced in two strains (C57BL and BALB/c) of senescent mice. The incorporation of [U-14C]glucose into acetylcholine decreased in both strains by 40 +/- 4 per cent in 10-month-old mice and by 58 +/- 9 percent in 30-month-old mice compared with mice 3 months old. The incorporation of [2H4]choline into acetylcholine declined 60 and 73 percent in 10- and 30-month-old mice, respectively. Deficits in the cholinergic system may contribute to brain dysfunctions that complicate senescence.