Nucleus accumbens and medial prefrontal cortex dopaminergic response to self-administered cocaine in naive rats.
Cocaine reinforcement is strongly associated with increased nucleus accumbens dopamine (NAcc DA). The involvement of medial prefrontal cortex (mPFC) DA in cocaine reward is less defined, but substantial evidence indicates that increased mPFC DA may suppress NAcc DA levels. Using in vivo microdialysis, NAcc or mPFC DA was determined in cocaine-naive rats after a self-administered cocaine injection (3.0 mg/kg). Extracellular levels of NAcc DA were dramatically enhanced 10 min post-cocaine injection, but dropped significantly at each subsequent assessment. mPFC DA also increased significantly, but to a lesser extent than observed in the NAcc. Findings of prominent DA increases in both the NAcc and mPFC terminals during the test session indicate that NAcc DA responses do not appear to be inhibited by increased mPFC DA during cocaine self-administration.
Ikegami
Aiko
A
College of Pharmacy, Division of Pharmacology and Toxicology and the Waggoner Center for Alcohol and Addiction Research, The University of Texas, Austin, TX 78712-0125, USA.
Duvauchelle
Christine L
CL
D000704:Analysis of Variance; D000818:Animals; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D005110:Extracellular Space / Q000378:metabolism; D008297:Male; D017551:Microdialysis / Q000379:methods; D009043:Motor Activity / Q000187:drug effects; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D017397:Prefrontal Cortex / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012646:Self Administration
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine; D004298:Dopamine