Esparza MA et al. – The study shows that a history of repeated stress alters the ability of a subsequent cocaine injection to modulate dendritic spine morphology, actin dynamics and GluR1 expression in the nucleus accumbens (NAc). Furthermore, by regulating GluR1 expression in the NAc, elevated actin cycling contributes to the expression of cross–sensitization between stress and cocaine, while stress–induced changes in the prefrontal cortex (Pfc) were not associated with cross–sensitization. [more...]