title: Explicit disassociation of a conditioned stimulus and unconditioned stimulus during extinction training reduces both time to asymptotic extinction and spontaneous recovery of a conditioned taste aversion.
abstract: Conditioned taste aversions (CTAs) may be acquired when an animal consumes a novel taste (CS) and then experiences the symptoms of poisoning (US). This aversion may be extinguished by repeated exposure to the CS alone. However, following a latency period in which the CS is not presented, the CTA will spontaneously recover (SR). In the current study we employed an explicitly unpaired extinction procedure (EU-EXT) to determine if it could thwart SR of a CTA. Sprague-Dawley rats acquired a strong CTA after 3 pairings of saccharin (SAC the CS) and Lithium Chloride (LiCl the US). CTA acquisition was followed by extinction (EXT) training consisting of either (a) CS-only exposure (CSO) or, (b) exposure to saccharin and Lithium Chloride on alternate days (i.e., explicitly unpaired: EU). Both extinction procedures resulted in >/= 90% reacceptance of SAC, although the EU extinction procedure (EU-EXT) significantly decreased the time necessary for rats to reach this criterion (compared to CSO controls). Rats were subsequently tested for SR of the CTA upon re-exposure to SAC following a 30-day latency period of water drinking. Rats that acquired a CTA and then underwent the CSO extinction procedure exhibited a significant suppression of SAC drinking during the SR test (as compared to their SAC drinking at the end of extinction). However, animals in the EU-EXT group did not show such suppression in drinking compared to CSO controls. These data suggest that the EU-EXT procedure may be useful in reducing both time to extinction and the spontaneous recovery of fears.
authors.affiliation: Department of Psychology and The Neuroscience Program, Baldwin-Wallace College, Berea, OH 44017 USA.
authors.forename: G Andrew
authors.initials: GA
authors.lastname: Mickley
authors.forename: Anthony
authors.initials: A
authors.lastname: Disorbo
authors.forename: Gina N
authors.initials: GN
authors.lastname: Wilson
authors.forename: Jennifer
authors.initials: J
authors.lastname: Huffman
authors.forename: Stephanie
authors.initials: S
authors.lastname: Bacik
authors.forename: Zana
authors.initials: Z
authors.lastname: Hoxha
authors.forename: Jaclyn M
authors.initials: JM
authors.lastname: Biada
authors.forename: Ye-Hyun
authors.initials: YH
authors.lastname: Kim