 The reward-relevant actions of amphetamine and cocaine are in the dopaminergic synapses of the nucleus accumbens and perhaps the medial prefrontal cortex.Rats also learn to lever-press for cocaine injections into the medial prefrontal cortex, which works by increasing dopamine turnover in the nucleus accumbens.Nicotine infused directly into the nucleus accumbens also enhances local dopamine release, presumably by a presynaptic action on the dopaminergic terminals of this region.