Escalation of cocaine self-administration does not depend on altered cocaine-induced nucleus accumbens dopamine levels.

Serge H. Ahmed, Daniel Lin, George F. Koob, Loren H. Parsons
Journal of Neurochemistry. 2004-02-04; 86(1): 102-113
DOI: 10.1046/j.1471-4159.2003.01833.x

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