Top panels show representative immunoblots for pCB1 and the loading control β-tubulin in nucleus accumbens core (a, NAc core), nucleus accumbens shell (b, NAc shell), amygdala (c, Amy) and prefrontal cortex (d, PFC). Bar graphs show the quantification of pCB1 receptors immunoreactivity (double band quantification, see methods). Data on graphs are represented as mean ± SEM (n=4-5) and expressed as percentage values of the drug-naïve rats for each group in every brain structure after normalization by β-tubulin. Animals were sacrificed 24 h after the last cocaine session. LgA: long access to cocaine (filled bars); ShA: short access to cocaine (striped bars); Naïve: drug-naïve rats (open bars). Different from drug-naïve: *p<0.05; different from ShA rats: #p<0.05. β-tubulin expression was constant across the groups (p>0.05, n.s.).