Behavioral and physical development of rats chronically exposed to caffeinated fluids

Coffee and caffeine solutions were administered as the sole source of fluid to male and female Sprague-Dawley rats (F0) beginning 60 days before breeding and continuing until the litters (F1) from these animals were weaned. Treatments were administered as 100% brewed coffee (COF-100), and a 25% dilution of coffee (COF-25), together with solutions of caffeine in water that paralleled the caffeine content of the coffee groups, 0.056% caffeine (CAF-100) and 0.014% (CAF-25). Controls received measured amounts of plain water (CNL) and another group received vitamin A (40,000 IU/kg) on Days 7-20 of gestation (positive control treatment). During pregnancy all groups receiving COF and CAF consumed significantly more fluid than CNLs. Offspring from the COF-100 and CAF-100 dams were significantly lower in weight than CNLs. No abnormalities of reproductive performance were observed. Of 10 preweaning tests, COF-100 and CAF-100 litters displayed delayed incisor eruption, delayed swimming development, and altered activity. On 7 postweaning measures, these groups showed decreased running wheel activity and increased open-field ambulation and/or defecation. The CAF-25 group, by contrast, showed an increase in running wheel activity. Vitamin A (Vit-A) offspring showed multiple effects, including delayed incisor eruption, increased pre- and postweaning open-field activity, and reduced running wheel activity. COF and CAF produced effects on tests for psychoteratogenesis that appear consistent with the morphological consequences (delayed development) known to be associated with pre- and neonatal administration of caffeine, alone or in coffee, at high doses. The data indicate that most of the behavioral effects observed from caffeine exposure were consistent with the expected effects of concurrent administration of this agent, while the postweaning exposure effects suggest a longer-term change in activity. No effects of caffeine were found, however, on measures of learning, memory, or motoric functioning.