TY - JOUR
T1 - Bilateral lesions of the thalamic trigeminal orosensory area dissociate natural from drug reward in contrast paradigms
AU - Nyland, Jennifer E.
AU - Alexander, Danielle N.
AU - Liang, Nu Chu
AU - Grigson, Patricia S.
PY - 2012/8
Y1 - 2012/8
N2 - Substance abuse and addiction are associated with an apparent devaluation of, and inattention to, natural rewards. This consequence of addiction can be modeled using a reward comparison paradigm where rats avoid intake of a palatable taste cue that comes to predict access to a drug of abuse. Evidence suggests rats avoid intake following such pairings, at least in part, because the taste cue pales in comparison to the highly rewarding drug expected in the near future. In accordance, lesions of the gustatory thalamus or cortex eliminate avoidance of a taste cue when paired with either a drug of abuse or a rewarding sucrose solution, but not when paired with the aversive agent, LiCl. The present study used bilateral ibotenic acid lesions to evaluate the role of a neighboring thalamic structure, the trigeminal orosensory area (TOA), in avoidance of a gustatory cue when paired with sucrose (Experiment 1), morphine (Experiment 2), cocaine (Experiment 3), or LiCl (Experiment 4). The results show that the TOA lesion disrupts, but does not eliminate avoidance of a taste cue that predicts access to a preferred sucrose solution and leaves intact the development of a LiCl-induced conditioned taste aversion. The lesion does, however, eliminate the suppression of intake of a taste cue when paired with experimenter-administered morphine or cocaine using our standard parameters. As such, this is the first manipulation found to dissociate avoidance of a taste cue when mediated by a sweet or by a drug of abuse.
AB - Substance abuse and addiction are associated with an apparent devaluation of, and inattention to, natural rewards. This consequence of addiction can be modeled using a reward comparison paradigm where rats avoid intake of a palatable taste cue that comes to predict access to a drug of abuse. Evidence suggests rats avoid intake following such pairings, at least in part, because the taste cue pales in comparison to the highly rewarding drug expected in the near future. In accordance, lesions of the gustatory thalamus or cortex eliminate avoidance of a taste cue when paired with either a drug of abuse or a rewarding sucrose solution, but not when paired with the aversive agent, LiCl. The present study used bilateral ibotenic acid lesions to evaluate the role of a neighboring thalamic structure, the trigeminal orosensory area (TOA), in avoidance of a gustatory cue when paired with sucrose (Experiment 1), morphine (Experiment 2), cocaine (Experiment 3), or LiCl (Experiment 4). The results show that the TOA lesion disrupts, but does not eliminate avoidance of a taste cue that predicts access to a preferred sucrose solution and leaves intact the development of a LiCl-induced conditioned taste aversion. The lesion does, however, eliminate the suppression of intake of a taste cue when paired with experimenter-administered morphine or cocaine using our standard parameters. As such, this is the first manipulation found to dissociate avoidance of a taste cue when mediated by a sweet or by a drug of abuse.
KW - Contrast
KW - Ibotenic Acid lesion
KW - Reward comparison
KW - Thalamus
KW - Trigeminal
UR - http://www.scopus.com/inward/record.url?scp=84871884238&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84871884238&partnerID=8YFLogxK
U2 - 10.1037/a0028842
DO - 10.1037/a0028842
M3 - Article
C2 - 22687147
AN - SCOPUS:84871884238
SN - 0735-7044
VL - 126
SP - 538
EP - 550
JO - Behavioral Neuroscience
JF - Behavioral Neuroscience
IS - 4
ER -