Two experiments paired a novel sucrose solution (conditioned stimulus,
or CS) with injections of Ketaset-Rompun anesthesia (unconditioned st
imulus, or US) to examine the effects of this anesthetic on the develo
pment of conditioned taste aversions (CTA) in Sprague-Dawley rats. Exp
eriment 1 showed that using Ketaset-Rompun anesthesia as the US produc
ed a reliable taste aversion, as rats injected with the anesthetic imm
ediately after consumption of a novel sucrose solution drank significa
ntly less sucrose on a 24-hr retention test compared to rats injected
with an equivalent volume of saline at training. Additionally, Experim
ent 2 demonstrated that the level of Ketaset-Rompun-induced CTA varied
with the CS-US interval. In this experiment, rats injected with the a
nesthetic demonstrated an aversion to sucrose at testing if the presen
tation of the CS was followed by injections of the US either immediate
ly, 1 hr, or 2 hr later. However, when the US was administered 4 or 6
hr after presentation of the CS, no aversion to sucrose was manifested
at testing. Furthermore, the results of Experiment 2 suggest that the
largest CTA was obtained with the 2-hr delay condition. The methodolo
gical implications for researchers using Ketaset-Rompun for surgical i
nterventions is considered.