Valenza, M; Picetti, R; Yuferov, V; Butelman, ER; Kreek, MJ; (2016) Strain and cocaine-induced differential opioid gene expression may predispose Lewis but not Fischer rats to escalate cocaine self-administration. Neuropharmacology. ISSN 0028-3908 DOI: https://doi.org/10.1016/j.neuropharm.2016.01.004 Full text not available from this repository.