Morphine-induced suppression of conditioned stimulus intake: effects of stimulus type and insular cortex lesions.
Intake of an unconditionally preferred taste stimulus (e.g., saccharin) is reduced by contingent administration of a drug of abuse (e.g., morphine). We examined the influence of insular cortex (IC) lesions on morphine-induced suppression of an olfactory cue and two taste stimuli with different levels of perceived innate reward value. Two major findings emerged from this study. First, morphine suppressed intake of an aqueous odor as well as each taste stimulus in neurologically intact rats. Second, IC lesions disrupted morphine-induced suppression of the taste stimuli but not the aqueous odor cue. These results indicate that the perceived innate reward value of the CS is not a factor that governs drug-induced intake suppression.
Lin
Jian-You
JY
Department of Psychology, University of Illinois at Chicago, 1007 West Harrison Street, Chicago, IL 60607, USA.
Roman
Christopher
C
Reilly
Steve
S
D000818:Animals; D032084:Citrus sinensis; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology*; D003463:Cues; D004327:Drinking Behavior / Q000187:drug effects / Q000502:physiology; D008293:Malates; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology*; D009812:Odorants; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D010812:Physical Stimulation; D011897:Random Allocation; D051381:Rats; D012201:Reward; D012965:Sodium Chloride; D055697:Taste Perception / Q000187:drug effects / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology*; D013997:Time Factors; D014867:Water
D008293:Malates; D009294:Narcotics; D014867:Water; D012965:Sodium Chloride; D009020:Morphine; C030298:malic acid