INCREASE IN EXOGENOUS CHOLINE FAILS TO ELEVATE THE CONTENT OR TURNOVER RATE OF CORTICAL, STRIATAL, OR HIPPOCAMPAL ACETYLCHOLINE

The availability of choline was increased in rat brain to test whether increases in the rate of acetylcholine [ACh] synthesis occurred in that organ. The content of choline and ACh and the turnover rate of ACh in striatum, hippocampus and cerebral cortex were measured following changes in dietary choline, i.p. choline or i.v. infusion of choline. Increasing plasma choline caused some increase in tissue choline but did not increase ACh levels nor turnover rate in any of the areas of brain studied. In hippocampus, choline decreased the turnover rate of ACh.