withdrawal from cocaine self-administration. Importantly, infusing this compound into the NAc had no effect on cue-elicited drug seeking the first day of withdrawal nor on sucrose self-administration. Because GluA2-lacking AMPARs have a higher conductance than GluA2-containing AMPARs and this withdrawal period is associated with an increase in the AMPAR/NMDAR ratio, these findings are consistent with a general increase in excitatory synaptic strength in NAc MSNs during prolonged withdrawal from either self-administered or non-contingent administered cocaine (Russo et al., 2010; Kalivas et al., 2009; Wolf, 2010).
