title: Repeated cocaine exposure attenuates the ability of 5-hydroxytryptamine to release striatal dopamine in vivo.
abstract: Cocaine was administered repeatedly to rats and striatal microdialysis performed 1, 7, 14, or 21 days after the last cocaine injection. Local perfusion of 10 microM serotonin (5-hydroxytryptamine, 5-HT) increased basal dopamine levels approximately 7-fold (664 +/- 79%, 813 +/- 104% and 669 +/- 22%, n = 6, P < 0.0001) in saline-treated controls, whereas in cocaine-treated animals the effect was significantly attenuated (432 +/- 55%, 465 +/- 61% and 497 +/- 48% n = 6-10, P < 0.03) at 1, 7 and 14 days of withdrawal. The 5-HT effect on dopamine release returned to control levels 21 days after cocaine exposure and was not altered by acute cocaine treatment (30 mg/kg, i.p. 24 h prior). The results suggest that repeated cocaine administration attenuates the effectiveness of 5-HT on striatal dopaminergic activity.
authors.affiliation: Cellular and Clinical Neurobiology Program, Department of Psychiatry and Behavioral Neuroscience, Wayne State University School of Medicine, Detroit, MI 48201, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Norton
authors.forename: M P
authors.initials: MP
authors.lastname: Galloway
mesh_terms: D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D013375:Substance Withdrawal Syndrome / Q000209:etiology
chemical_list: D011985:Receptors, Serotonin; D012701:Serotonin; D003042:Cocaine; D004298:Dopamine