ETHANOL REINFORCEMENT AND ITS RELATIONSHIP TO SACCHARIN PREFERENCE INWISTAR RATS

Forty rats were given a choice between 0.1% sodium saccharin and water . Based on their intakes, three groups of six rats representing high, intermediate, and low saccharin preferences were selected. These rats were reduced to 80% of their free-feeding weights. Ethanol was establi shed as a reinforcer by use of a food-induced drinking procedure. Betw een-group differences were assessed based on response rates across acq uisition sessions (0, 1, 2, 4, 5.7, 8%, w/v), a fixed-ratio series (1, 2, 4, 8, 1), and a concentration series (8, 5.7, 4, 2, 2, 4, 5.7, 8, 11.3, 16, 22.6, 32, 8%, w/v). In 29 of 32 conditions which were analyz ed, the mean number of responses for ethanol was higher for the high s accharin preference group than for the low, and in 25 of 32 conditions , the intermediate group fell between the high and the low. However, t here was considerable variability within groups across all conditions, such that mean between-group differences were not significant. This v ariability may be reduced by considering diet preferences in addition to saccharin preference. Nonetheless, these results offer limited supp ort for the increasing body of evidence indicating a relationship betw een the factors mediating ethanol self-administration and those involv ing ingestion of palatable foods and fluids.