TITLE: Age differences in bdnf gene expression after cocaine self-administration or cue-induced reinstatement of cocaine-seeking in male rats

Introduction: Results from our behavioral pharmacology laboratory indicate that male rats that self-administer cocaine as adolescents exhibit decreased vulnerability to subsequent cue-induced reinstatement of cocaine-seeking, as compared with adults. An important neuroplasticity-related gene that influences such drug-seeking behavior and differs across age groups is brain-derived neurotrophic factor (bdnf). BDNF mRNA is expressed in regions of the brain known to be critical for reward and reinforcement-related behavior. Based on reports that BDNF in the prefrontal cortex attenuates cue-induced reinstatement in adult rats, whereas BDNF in the nucleus accumbens increases reinstatement, we hypothesized that cocaine-seeking would correlate with higher expression of BDNF mRNA in the prefrontal cortex but lower expression in the nucleus accumbens of younger animals compared with adults.