SUMMARY Psychomotor-stimulant Use Disorder (PUD) is a chronic relapsing disorder, characterized by a high propensity for relapse even during protracted abstinence. In both humans with PUD & animal models, the intensity of cue- elicited drug craving & drug-seeking behavior increases or “incubates” during protracted withdrawal. The neurochemical underpinnings of drug craving & its incubation are not well understood. Drug cue-induced increase in metabolic hyperactivity within the medial prefrontal cortex (mPFC) is correlated with the intensity of drug-craving in humans. Consistent with this, we have reported a link between the magnitude of drug-seeking in a rat model of cocaine-taking & an increased activational state of several kinases, including mTOR, Akt, PI3K & PKCε. My dissertation work also identified increased indices of calcium-calmodulin-dependent kinase II (CaMKII) activation within the prelimbic cortex (PL) subregion of the mPFC, that appears to be selective for cocaine as it is not observed in rats exhibiting incubated sucrose-seeking. CaMKII has long been considered central to long- term plasticity implicated in learning/memory & substance use disorders. Despite this, no published report has examined the role for CaMKII activation within PFC subregions in cocaine-craving, let alone its incubation during protracted withdrawal. CaMKII can be activated by the influx of calcium inhibition through calcium-permeable ionotropic glutamate receptors, including NMDA and GluA2-lacking AMPA receptors, which I propose are activated by the cue-sensitized glutamate release in cocaine incubated rats. Activated CaMKII can regulate AMPA and NMDA receptor signaling and synaptic plasticity, which may drive the cocaine-incubated state. The objective of the F99 phase of this proposal is to investigate the role of NMDA-CaMKII in the mPFC in incubated cocaine-seeking using neuropharmacological techniques. The proposed project will also help the candidate, Ms. Laura Huerta Sanchez, achieve her career goal of becoming an independent investigator at a top-tier academic/research institution. This project provides training in valuable research techniques, including immunoblotting, cytology & histology & neuropharmacological approaches. Further, the proposed studies will provide professional & technical training to prepare the candidate to successfully transition to a postdoctoral position (K00) in a laboratory that studies the neural circuitry driving vulnerability to drug-seeking behavior. The complete plan proposed here for both the F99 and K00 phases has been designed to develop an independent neurobiologist prepared for a transition to a successful postdoctoral position and, ultimately, independent tenured investigator.