Once is too much: Conditioned changes in accumbens dopamine following a single saccharin-morphine pairing
| Autor: | Patricia S. Grigson, Andras Hajnal |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Male
Narcotics medicine.medical_specialty Microdialysis Time Factors Dopamine Nucleus accumbens Nucleus Accumbens Rats Sprague-Dawley Behavioral Neuroscience chemistry.chemical_compound Saccharin Internal medicine Conditioning Psychological medicine Animals Neurotransmitter Behavior Animal Morphine Classical conditioning Rats Endocrinology chemistry Sweetening Agents Taste aversion Psychology Neuroscience psychological phenomena and processes medicine.drug |
| Zdroj: | Behavioral Neuroscience. 121:1234-1242 |
| ISSN: | 1939-0084 0735-7044 |
| Popis: | The present study tested whether presentation of a taste cue would support conditioned suppression of dopamine in the nucleus accumbens (NAcc) following a single taste-drug pairing. Nondeprived male Sprague-Dawley rats were given 20-min access to a 0.15% saccharin conditioned stimulus (CS). Immediately thereafter, experimental rats were injected with morphine (15 mg/kg ip); standard controls were injected with saline; and explicitly unpaired controls were injected with morphine, but approximately 24 hr later. All rats were then given one 20-min CS-only test. Microdialysis samples from the NAcc were measured over 20-min intervals before, during, and after CS access on the conditioning and test trial. The results showed that a single saccharin-morphine pairing led to a marked reduction in CS intake, and the reduction in intake was accompanied by a conditioned blunting of the accumbens dopamine response to the saccharin reward cue. In turn, a single exposure to the saccharin cue also blunted the unconditioned dopamine response to morphine. Reward comparison effects, then, are cross-modal, bidirectional, and immediate, resulting in both unconditioned and conditioned changes in brain and behavior. |
| Databáze: | OpenAIRE |
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