Choline supplementation during prenatal development reduces proactive interference in spatial memory

Previous research has demonstrated that increasing dietary choline during e arly development can have long-lasting effects on cholinergic (Ch) function that are correlated with improvement of spatial memory ability in rats. Th e present study is designed to further our understanding of these organizat ional changes in brain and behavior by examining the effects of spaced vs. massed trials. A third of the rats (n = 10) were supplemented with choline chloride prenatally by adding it to the drinking water of their dams. Anoth er third were made deficient of choline during early development by removin g choline from the dams diet. The remaining rats served as untreated contro ls. Postnatally, the offspring were maintained on a choline-sufficient diet and at 120 days of age they began 12-arm radial maze training. The maze da ta revealed two major effects of early choline availability: (1) Both choli ne-supplemented and choline-deficient rats performed mon accurately than co ntrol Littermates when trials were spaced. These differences in spatial abi lity did not appear to be a function of differential response or cue-use st rategies. (2) Choline-supplemented rats showed little proactive interferenc e when trials were massed: whereas control rats demonstrated moderate level s and choline-deficient rats exhibited high levels of proactive interferenc e as a function of massed trials. These data suggest that the behavioral co nsequences of early dietary availability of choline may involve the modific ation of the discriminative abilities used to attend to stimuli that demarc ate the end of one trial and the start of another as well as the capacity f or remembering the locations that have been visited during a trial. (C) 199 9 Elsevier Science B.V. All rights reserved.