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Amphetamine‐sensitized rats demonstrate enhanced nicotine‐stimulated locomotor activity and dopamine overflow
Author(s) -
Jutkiewicz Emily M,
Park Yang Hae,
Baladi Michelle G,
Gnegy Margaret E
Publication year - 2006
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.20.4.a677-c
Subject(s) - amphetamine , nicotine , stimulant , methylphenidate , saline , dopamine , sensitization , pharmacology , dextroamphetamine , medicine , anesthesia , psychology , attention deficit hyperactivity disorder , psychiatry , neuroscience
A relationship between stimulants and increased cigarette smoking in humans is well documented. Amphetamine increases the number of cigarettes smoked, the satisfaction derived from smoking, and assessments of smoking reinforcement. Methylphenidate also increases cigarette smoking that may contribute to enhanced smoking rates in adolescents with attention deficit‐hyperactivity disorder (ADHD). Previous studies have demonstrated that repeated exposure to psychostimulants produces long‐lasting sensitization to the behavioral effects of subsequent amphetamine challenge; however, little is known about the effects of repeated stimulant exposure on nicotine challenge. Therefore, the present study evaluated the effects of repeated amphetamine exposure on locomotor activity stimulated by nicotine challenge. Rats were injected once daily with either saline or 2.5 mg/kg d‐amphetamine for 5 d. Following a 10 d withdrawal period, rats were administered 0.56 mg/kg nicotine and locomotor activity was measured in the homecage by a telemetry system. Challenge with amphetamine or nicotine stimulated activity to a greater extent in amphetamine‐treated rats as compared with saline‐treated rats. In addition, nicotine‐stimulated dopamine overflow was enhanced in brain slices from amphetamine‐treated rats as compared with saline‐treated rats. Therefore, these data might suggest that repeated stimulant use enhances the effects of nicotine, potentially leading to elevated smoking behaviors in stimulant abusers and methylphenidate‐treated adolescents. Supported by USPHS grants DA00254 and UM Tobacco Research Network.