Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9415684 | Brain Research | 2005 | 6 Pages |
Abstract
Rats suppress intake of a saccharin cue when paired with a drug of abuse such as morphine or cocaine. Relative to Lewis rats, Fischer rats exhibit greater avoidance of a saccharin cue following saccharin-morphine pairings. The present study used the μ agonist, [d-Ala2,N-MePhe4,Gly-ol5]enkephalin (DAMGO), to test whether strain differences in sensitivity of the μ receptor contribute to this effect. Water-deprived Lewis and Fischer rats were given 5 min access to 0.15% saccharin followed by an icv injection of either DAMGO (0.5 microg/1 microl/rat) or an equal volume of saline. There were six taste-drug pairings occurring at 48 h intervals. The results showed that, relative to the saline treated controls, all rats reduced intake of the saccharin cue following saccharin-DAMGO pairings. No differences occurred between strains. These data suggest that greater morphine-induced suppression of saccharin intake by the Fischer rats is not likely mediated by differences in sensitivity of the μ receptor. Other mechanisms are implicated.
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Neuroscience (General)
Authors
Chuang Liu, Patricia Sue Grigson,