Nucleus accumbens and medial prefrontal cortex dopaminergic response to self-administered cocaine in naive rats

• Published in: Neuroscience letters Vol. 354; no. 3; pp. 205 - 208
• Main Authors: Ikegami, Aiko, Duvauchelle, Christine L.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 16.01.2004; Elsevier
• Subjects: Analysis of Variance; Animals; Biological and medical sciences; Cocaine - administration & dosage; Cocaine - pharmacology; Cocaine self-administration; Dopamine - metabolism; Dopamine Uptake Inhibitors - administration & dosage; Dopamine Uptake Inhibitors - pharmacology; Extracellular dopamine; Extracellular Space - metabolism; Fundamental and applied biological sciences. Psychology; In vivo microdialysis; Locomotor activity; Male; Microdialysis - methods; Motor Activity - drug effects; Nucleus Accumbens - drug effects; Nucleus Accumbens - metabolism; Nucleus accumbens core; Prefrontal Cortex - drug effects; Prefrontal Cortex - metabolism; Prelimbic prefrontal cortex; Rats; Rats, Sprague-Dawley; Self Administration; Vertebrates: nervous system and sense organs; Nucleus accumbens core; In vivo microdialysis; Extracellular dopamine; Cocaine self-administration; Locomotor activity; Prelimbic prefrontal cortex; Cocaine sell-administration; Dopamine; Rat; Rodentia; Central nervous system; Basal ganglion; Prefrontal cortex; Catecholamine; Extracellular; Encephalon; Nucleus accumbens; Vertebrata; Mammalia; Microdialysis; Animal; Neurotransmitter; Cocaine
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2003.10.033

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.