Time-dependent exacerbation of amphetamine-induced taste aversions following exposure to footshock.

Previous studies have shown that stressors attenuate LiCI-induced conditioned taste aversions (CTA) but not morphine-induced CTA. The current studies examined the effects of footshock on the acquisition and extinction of amphetamine-induced CTA. Experiment 1 demonstrated that exposure to 30 footshocks between saccharin consumption and amphetamine injections did not alter either the acquisition or the extinction of amphetamine-CTA. Experiment 2 demonstrated that exposure to the same shock parameters 2 and 4 days before saccharin-amphetamine pairing increased the magnitude of amphetamine-CTA after one saccharin-amphetamine pairing and delayed the recovery from the CTA. Experiment 2 also demonstrated that footshock increased the initial neophobic response to novel saccharin but did not alter subsequent saccharin consumption among saline-injected animals. These results indicate that stress-induced facilitation of amphetamine CTA are time-dependent and contrast with reports that stressors attenuate LiCI CTA. They also add support to the contention that CTAs induced by self-administered drugs like amphetamine are qualitatively different from CTAs induced by toxic substances like LiCL.