TY - JOUR
T1 - Acquisition of responding with a remifentanil-associated conditioned reinforcer in the rat
AU - Bertz, Jeremiah W.
AU - Woods, James H.
N1 - Funding Information:
Acknowledgments We thank Davina Barron, Alyssa Cunningham, Tomas Davaloz, and Adam Kynaston for their excellent technical assistance. We thank Gail Winger and Nhu Truong for their comments on an earlier draft of the manuscript. This research was supported by NIDA grants DA 020669, DA 024897, and DA 032943 and by the NSF Graduate Research Fellowship Program under grant DGE 0718128.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013/9
Y1 - 2013/9
N2 - Rationale: Drug-associated environmental stimuli may serve as conditioned reinforcers to enhance drug self-administration behaviors in humans and laboratory animals. However, it can be difficult to distinguish experimentally the conditioned reinforcing effects of a stimulus from other behavioral processes that can change rates of responding. Objectives: To characterize the conditioned reinforcing effects of a stimulus paired with the μ-opioid agonist, remifentanil, using a new-response acquisition procedure in the rat. Methods: First, in Pavlovian conditioning (PAV) sessions, rats received response-independent IV injections of remifentanil and presentations of a light-noise compound stimulus. In paired PAV groups, injections and stimulus presentations always co-occurred. In random PAV control groups, injections and stimulus presentations occurred with no consistent relationship. Second, in instrumental acquisition (ACQ) sessions, all animals could respond in an active nose-poke that produced the stimulus alone or in an inactive nose-poke that had no scheduled consequences. Results: During ACQ, rats made significantly more active nose-pokes than inactive nose-pokes after paired PAV, but not after random PAV. Between groups, rats also made more active nose-pokes after paired PAV than after random PAV. After paired PAV, increased active responding was obtained under different schedules of reinforcement, persisted across multiple ACQ sessions, and depended on the number of PAV sessions conducted. Conclusions: The remifentanil-paired stimulus served as a conditioned reinforcer for nose-poking: responding depended on both the contingency between the stimulus and remifentanil and the contingency between the nose-poke and the stimulus. Generally, new-response acquisition procedures may provide valid, flexible models for studying opioid-based conditioned reinforcement.
AB - Rationale: Drug-associated environmental stimuli may serve as conditioned reinforcers to enhance drug self-administration behaviors in humans and laboratory animals. However, it can be difficult to distinguish experimentally the conditioned reinforcing effects of a stimulus from other behavioral processes that can change rates of responding. Objectives: To characterize the conditioned reinforcing effects of a stimulus paired with the μ-opioid agonist, remifentanil, using a new-response acquisition procedure in the rat. Methods: First, in Pavlovian conditioning (PAV) sessions, rats received response-independent IV injections of remifentanil and presentations of a light-noise compound stimulus. In paired PAV groups, injections and stimulus presentations always co-occurred. In random PAV control groups, injections and stimulus presentations occurred with no consistent relationship. Second, in instrumental acquisition (ACQ) sessions, all animals could respond in an active nose-poke that produced the stimulus alone or in an inactive nose-poke that had no scheduled consequences. Results: During ACQ, rats made significantly more active nose-pokes than inactive nose-pokes after paired PAV, but not after random PAV. Between groups, rats also made more active nose-pokes after paired PAV than after random PAV. After paired PAV, increased active responding was obtained under different schedules of reinforcement, persisted across multiple ACQ sessions, and depended on the number of PAV sessions conducted. Conclusions: The remifentanil-paired stimulus served as a conditioned reinforcer for nose-poking: responding depended on both the contingency between the stimulus and remifentanil and the contingency between the nose-poke and the stimulus. Generally, new-response acquisition procedures may provide valid, flexible models for studying opioid-based conditioned reinforcement.
KW - Conditioned reinforcement
KW - Cues
KW - Opioid
KW - Pavlovian conditioning
KW - Response acquisition
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U2 - 10.1007/s00213-013-3102-0
DO - 10.1007/s00213-013-3102-0
M3 - Article
C2 - 23609770
AN - SCOPUS:84883457664
VL - 229
SP - 235
EP - 243
JO - Psychopharmacology
JF - Psychopharmacology
SN - 0033-3158
IS - 2
ER -