The effects of cholecystokinin octapeptide (CCK-8), and its antagonist proglumide, upon conditioned behavior in the rat was studied. First, the effects of CCK-8 and proglumide upon passive avoidance behavior was investigated. Rats were trained to avoid a darkened chamber by presenting electrical footshock (two seconds of intensity levels) inside the chamber. Directly following the footshock, injections of CCK-8 or proglumide were given, with avoidance behavior measured 24 hours following the injection. CCK-8 was found to produce reductions in the passive avoidance latency at doses ranging from 30 ug/Kg to 500 ug/Kg. This effect was found to be dependent upon the current intensity used during conditioning. The CCK-8 effect was found when the current was at 0.25 mA, but at no other current setting tested. Proglumide (5 mg/Kg) was found to block the CCK-8 effect upon passive avoidance behavior. A lower dose of proglumide (2 mg/Kg) was found to produce reductions in the passive avoidance latency. These results suggest that CCK-8 may play a role in passive avoidance conditioning in rats. The effects of CCK-8 upon an appetitively conditioned behavior were then investigated. Rats were trained to locate and drink from a drinking tube that contained a 10 percent sucrose solution. Following 30 seconds exposure to the solution, injections of CCK-8 were given, with the latency to begin drinking from the tube measured 24 hours later. CCK-8 was found to produce increases in the latency to begin drinking, at doses of 20 ug/Kg and 100 ug/Kg. CCK-8 also produced a reduction in the amount of sucrose solution consumed during the test period. When CCK-8 was given following exposure to regular tap water, no increase in drinking latency or reduction in consumption was found. These results suggest that CCK-8 can act as an aversive stimulus and is capable of producing conditioned taste aversions. The results of this dissertation project demonstrate that CCK-8 can influence the acquisition of conditioned behavior in the rat when the octapeptide is paired with the presentation of an unconditioned stimulus (shock or sucrose).
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/183835 |
| Date | January 1986 |
| Creators | Deupree, David Lee |
| Contributors | Hsiao, Sigmund, Aposhian, H. Vasken, Lansing, Robert, Pickens, Peter |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | text, Dissertation-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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