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Modulation of the cocaine cue by predictable and unpredictable stress in rats: relation to monoamine transporter levels
Author(s) -
Kohut Stephen J,
DeCiccoSkinner Kathleen L,
Riley Anthony L
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.768.7
Subject(s) - monoamine neurotransmitter , serotonin transporter , psychology , norepinephrine transporter , dopamine transporter , dopamine , serotonin , stressor , saline , reinforcement , endocrinology , medicine , norepinephrine , neuroscience , receptor , social psychology , dopaminergic
Discriminative stimuli (SD) play an important role in the acquisition, maintenance and reinstatement of drug‐taking behavior and are altered by a variety of manipulations, including stress. The present study tested whether two different schedules of stressor presentation (predictable; PS and unpredictable; UPS) for 10 days can modify the discriminative effects of cocaine in male rats trained to discriminate cocaine (10 mg/kg) from saline. Dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporter levels in mesolimbic areas were also measured after stress to see if the relative ratio of these proteins may explain differences in behavior. In handled (H) rats, ED50s for cocaine‐like responding were stable after 10 days of handling compared to baseline. Animals exposed to PS and UPS displayed shifts in the cocaine dose‐response curve after stress but with different patterns of responding. PS produced a time‐dependent left‐ward shift in cocaine‐like responding, indicating increased sensitivity to the cocaine cue after stress. ED50s after UPS did not differ from baseline, although maximal cocaine‐like responding was lower at the two highest doses of cocaine tested where UPS rats switched from cocaine to saline‐like responding. DAT and SERT levels were different in select brain regions in UPS compared to P/H and in P compared to H which may explain the differences in behavior.