Environmental enrichment counters cocaine abstinence-induced stress and brain reactivity to cocaine cues but fails to prevent the incubation effect.
| Autor: | Thiel KJ; Department of Psychology, Arizona State University, Tempe, AZ 85287, USA., Painter MR, Pentkowski NS, Mitroi D, Crawford CA, Neisewander JL |
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| Jazyk: | angličtina |
| Zdroj: | Addiction biology [Addict Biol] 2012 Mar; Vol. 17 (2), pp. 365-77. Date of Electronic Publication: 2011 Aug 04. |
| DOI: | 10.1111/j.1369-1600.2011.00358.x |
| Abstrakt: | Environmental enrichment (EE) during a period of forced abstinence attenuates incentive motivational effects of cocaine-paired stimuli. Here we examined whether EE during forced abstinence from cocaine self-administration would prevent time-dependent increases in cue-elicited cocaine-seeking behavior (i.e. the incubation effect). Rats were trained to self-administer cocaine, which was paired with light/tone cues, for 15 days while living in isolated conditions (IC). Controls received yoked saline infusions. Subsequently, rats were assigned to live in either continued IC or EE for either 1 or 21 days of forced abstinence prior to a test for cocaine-seeking behavior. During testing, responding resulted only in presentation of the light/tone cues. Contrary to our prediction, cocaine-seeking behavior increased over time regardless of living condition during abstinence; however, EE attenuated cocaine-seeking behavior relative to IC regardless of length of abstinence. Brains were harvested and trunk blood was collected immediately after the 60-minute test and later assayed. Results indicated that short-term EE elevated hippocampal brain-derived neurotrophic factor and reduced plasma corticosterone compared with IC. Furthermore, 21 days of EE during forced abstinence prevented increases in the cue-elicited amygdala phosphorylated extracellular signal-regulated kinase expression that was observed in IC rats. These findings suggest that EE attenuates incentive motivational effects of cocaine cues through a mechanism other than preventing the incubation effect, perhaps involving reduction of stress and neural activity in response to cocaine-paired cues during acute withdrawal. (© 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.) |
| Databáze: | MEDLINE |
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