Hyponeophagia in Wistar Kyoto (WKY) rats.

Unconditioned suppression of feeding due to novelty (hyponeophagia) was studied in Wistar Kyoto (WKY), Lewis, Fischer 344, and Wistar rats. Fasted rats were given access to food either in home cages (controls) or to a single pellet fixed to the middle of a novel open field environment (experimental). The degree of feeding suppression was significantly greater in WKY rats compared to the other three strains. We suggest that this hyponeophagia resembles the reduced feeding frequently associated with behavioral depression, and that this behavior in WKY rats is another demonstration that this strain is very responsive to stressful stimulation and may serve as a useful animal model for depressive behavior.