Stress-induced sensitization to cocaine: actin cytoskeleton remodeling within mesocorticolimbic nuclei.

ESPARZA A; BOLLATTI F; GARCIA KELLER C; VIRGOLINI M; LÓPEZ M; BRUSCO A; KALIVAS PW; CANCELA L.M

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2012 vol. 36 p. 3103 - 3103

his study investigated the consequence of repeated stress on actin cytoskeleton remodeling in the nucleus accumbens (NAc) and prefrontal cortex (Pfc), and the involvement of this remodeling in the expression of stress-induced motor cross-sensitization with cocaine. Wistar rats were restrained daily (2h) for 7days and, 3 weeks later, their NAc and Pfc were dissected 45min after acute saline or cocaine (30mg/kg i.p.). F-actin, actin-binding proteins (ABP) and GluR1 were quantified by Western blotting, and dendritic spines and postsynaptic density (PSD) size measured by electron microscopy. In the NAc from the stress plus cocaine group we observed a decrease in the phosphorylation of two ABPs, cofilin and cortactin, and an increase in the PSD size and the surface expression of GluR1, consistent with a more highly branched actin cytoskeleton. The Pfc also showed evidence of increased actin polymerization after stress as an increase was observed in Arp2, and in the number of spines.