Jung S Kim1, Tommy Gunawan1, Christopher S Tripoli1, Alan Silberberg1, David N Kearns2. 1. Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States. 2. Department of Psychology, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016, United States. Electronic address: kearns@american.edu.
Abstract
BACKGROUND: Economy type is an important determinant of reinforcer value. This study investigated the effect of open and closed economies on demand and preference for cocaine and saccharin in rats. METHODS: In the first phase, rats were trained to lever press for cocaine infusions or saccharin. The number of presses required for each reinforcer increased across sessions. Cocaine and saccharin economy type was manipulated over groups by varying post-session availability of these reinforcers. One group of rats had three hours' post-session access to unlimited cocaine (open economy). A second group had three hours' post-session access to unlimited saccharin. A third group had no post-session access to either reinforcer (closed economy). In a second phase, rats in the three conditions could make mutually exclusive choices for cocaine or saccharin. RESULTS: Post-session access to saccharin caused saccharin demand to become more elastic. Post-session access to cocaine had no effect on demand for cocaine but made demand for saccharin more elastic. Results from the choice phase generally paralleled those from the demand phase, the main finding being that post-session saccharin access caused an increase in cocaine preference. CONCLUSIONS: These results show that manipulating economy type can affect cocaine and non-drug reinforcers differently. Opening the saccharin economy decreased saccharin's value. Opening the cocaine economy did not decrease cocaine's value, but instead led to a devaluation of saccharin. These results suggest that cocaine choice may be determined not only by the reinforcers immediately available, but also by those reinforcers' broader contexts of availability.
BACKGROUND: Economy type is an important determinant of reinforcer value. This study investigated the effect of open and closed economies on demand and preference for cocaine and saccharin in rats. METHODS: In the first phase, rats were trained to lever press for cocaine infusions or saccharin. The number of presses required for each reinforcer increased across sessions. Cocaine and saccharin economy type was manipulated over groups by varying post-session availability of these reinforcers. One group of rats had three hours' post-session access to unlimited cocaine (open economy). A second group had three hours' post-session access to unlimited saccharin. A third group had no post-session access to either reinforcer (closed economy). In a second phase, rats in the three conditions could make mutually exclusive choices for cocaine or saccharin. RESULTS: Post-session access to saccharin caused saccharin demand to become more elastic. Post-session access to cocaine had no effect on demand for cocaine but made demand for saccharin more elastic. Results from the choice phase generally paralleled those from the demand phase, the main finding being that post-session saccharin access caused an increase in cocaine preference. CONCLUSIONS: These results show that manipulating economy type can affect cocaine and non-drug reinforcers differently. Opening the saccharin economy decreased saccharin's value. Opening the cocaine economy did not decrease cocaine's value, but instead led to a devaluation of saccharin. These results suggest that cocaine choice may be determined not only by the reinforcers immediately available, but also by those reinforcers' broader contexts of availability.
Authors: Sally L Huskinson; Joel Myerson; Leonard Green; James K Rowlett; William L Woolverton; Kevin B Freeman Journal: Exp Clin Psychopharmacol Date: 2016-12 Impact factor: 3.157
Authors: Tommy Gunawan; Yosuke Hachiga; Christopher S Tripoli; Alan Silberberg; David N Kearns Journal: Psychopharmacology (Berl) Date: 2020-01-29 Impact factor: 4.530
Authors: Giuseppe Giannotti; Francesca Mottarlini; Jasper A Heinsbroek; Mitchel R Mandel; Morgan H James; Jamie Peters Journal: Transl Psychiatry Date: 2022-10-04 Impact factor: 7.989