Neophobia and water intake after repeated pairings of novel flavors with toxicosis

Abstract

The ability of rats (a) to acquire a generalized neophobia and (b) to maintain total daily fluid intake (by increasing intake of plain water) during the neophobia, was assessed. Rats trained to drink on a 23 1/2-hr water deprivation schedule were presented with a series of novel-flavored drinking solutions at 4-day intervals. Fifteen min of exposure to the novel flavor was followed first by 15 min of access to plain water, and then by an injection of lithium chloride. A saline-injected group and a noncontingent lithium chloride-injected group served as controls. Re-exposure to flavors did not occur between presentations of novel flavors. The rats in the group receiving novel flavors paired with toxicosis not only showed suppressed intake of all subsequent novel flavors after several pairings, but also eventually showed suppressed intake of plain water, which was limited to the days of novel-flavor presentation.