ReviewThe runway model of drug self-administration
Section snippets
The runway drug self-administration model
Animal learning researchers have been using operant runways as a tool for the study of goal-seeking motivated behavior for the better part of a century (e.g., see early classic studies by Crespi, 1942, Hull, 1934, Miller, 1944). In such studies, the time required for the subject to traverse the alley (i.e., Run Time) has proven to be a reliable index of the animal's motivation to seek the incentive that is made available upon goal box entry. Put simply, changes in the subject's motivation to
Dissociating the motivational and reinforcing actions of drugs of abuse
Much of our work on the neurobiology of drug-seeking motivation and/or reinforcement has involved investigations of the impact of the D2-family dopamine receptor antagonist, haloperidol, on the runway behavior of rats working for iv diacetylmorphine (heroin) (e.g., Ettenberg and McFarland, 2003, McFarland and Ettenberg, 1995, McFarland and Ettenberg, 1998a). Each of these studies employed external cues associated with drug delivery to experimentally “activate” or arouse the subjects' motivation
Runway response reinstatement test
Another means of studying the motivational impact of drug reinforcers is to assess their ability, or the ability of environmental cues associated with the drugs, to reinstate responding in animals whose operant behavior has been weakened by reinforcer removal (i.e., extinction trials). There have been numerous animal studies employing response-reinstatement tests as a means of modeling the “relapse” back to drug-taking behavior that human addicts often exhibit after a period of abstinence (see
The opponent-process properties of self-administered cocaine
An early and unexpected finding of our research program was the unique behavioral profile of animals running the alley for IV cocaine. In previous studies using natural and drug reinforcers, the subjects run the alley faster as trials progressed. In contrast, while cocaine-reinforced animals exhibited “normal” start latencies, they took progressively longer to actually reach the goal box over trials/days. Data from the infrared emitter–detector pairs lining the base of the runway, revealed that
Summary and conclusions
The runway self-administration test represents a hybrid model of drug-motivated behavior that incorporates the key procedural aspects of both the conditioned place preference and lever-press self-administration tests. As with the CPP method, animals are tested undrugged for their approach to a distinct location associated with prior drug administration (in this case the goal box); and like the traditional self-administration test, the animals must emit an operant response (in this case running
Acknowledgments
The development and implementation of the runway model of drug self-administration described in this paper would not have been possible without the dedication, motivation and considerable talents of the many students and technicians that have worked in the UCSB Behavioral Pharmacology Laboratory over the past two decades. Particular thanks to the co-authors of the many papers cited throughout this review including Rick Bernardi, the late Carter Camp, Ami Cohen, Dr. Cristine Czachoswki, Dr.
References (94)
- et al.
Heightened drug-seeking motivation following extended daily access to self-administered cocaine
Prog Neuropsychopharmacol Biol Psychiatry
(2008) - et al.
Schedule-dependent effects of haloperidol and amphetamine: multiple-schedule task shows within-subject effects
Pharmacol Biochem Behav
(2001) - et al.
Dopamine and drug addiction: the nucleus accumbens shell connection
Neuropharmacology
(2004) Haloperidol prevents the reinstatement of amphetamine-rewarded runway responding in rats
Pharmacol Biochem Behav
(1990)Opponent process properties of self-administered cocaine
Neurosci Biobehav Rev
(2004)- et al.
Anxiolytic-like actions of buspirone in a runway model of intravenous cocaine self-administration
Pharmacol Biochem Behav
(2006) - et al.
Effects of buspirone on the immediate positive and delayed negative properties of intravenous cocaine as measured in the conditioned place preference test
Pharmacol Biochem Behav
(2007) - et al.
Haloperidol induces a partial reinforcement extinction effect in rats: implications for a dopamine involvement in food reward
Pharmacol Biochem Behav
(1986) - et al.
Qualitative and quantitative differences in the operant runway behavior of rats working for cocaine and heroin reinforcement
Pharmacol Biochem Behav
(1993) - et al.
Pimozide prevents the response-reinstating effects of water reinforcement in rats
Pharmacol Biochem Behav
(1990)