Extinction and reinstatement of cocaine-seeking in self-administering mice is associated with bidirectional AMPAR-mediated plasticity in the nucleus accumbens shell.

•Cocaine self-administration produces synaptic plasticity in the nucleus accumbens.•Extinction of cocaine-seeking behavior is associated with synaptic strengthening.•Reinstated cocaine-seeking behavior is negatively correlated with synaptic strength.•Different mechanisms are involved in reinstatement induced by different stimuli.