Alcohol consumption and gustatory hedonic profiles in Wistar-Kyoto hyper- and normoactive rat strains

The purpose of the present study was to compare the consummatory behaviour of rats of the Wistar Kyoto Hyperactive (WKHA) strain, selected for their hyperactivity in a novel environment, with the normoactive Wistar-Kyoto (WKY) rats in three choice tasks: between water and increasing concentrations of saccharin, between water and increasing concentrations of quinine, and between water and a 10% (v/v) ethanol solution. The results of the present study show that: (1) WKHA rats exhibited a significantly higher acceptance of a 10% (v/v) alcohol solution than the normoactive control WKY rats when alcohol solution was the only available fluid; (2) WKHA rats also showed significantly larger alcohol intakes during the 15 days of choice between water and alcohol (WKY: 0.39 +/- 0.05; WKHA: 1.72 +/- 0.26 g/kg/day); (3) as frequently cited in the literature for other strains, the higher level of alcohol ingestion of WKHA rats was associated with a higher preference for saccharin; (4) no strain differences were observed in the water-quinine choice test. The discussion is mainly centred on the small alcohol consumption of the two strains, since the intake of WKHA rats is in the normal range for consumption of outbred strains, while the amount of alcohol consumption of WKY rats is very low and in the range of alcohol intake of non-preferring rat strains. It is concluded that the difference in alcohol consumption is mainly due to the low intake of the WKY rats and it is suggested that their different level of consumption might result from the particular behavioural profile of these rats.