Behavioral and dopamine sensitization to cocaine is absent in Proenkephalin Knockout mice: lack of neuroadaptations in AMPA receptor surface expression and BDNF/TrkB signaling in nucleus accumbens

BETHANIA MONGI-BRAGATO ; EMILIANO ZAMPONI; MARIA A ESPARZA; MARIA AMPARO ASSIS; MIRIAM B VIRGOLINI; DANIEL MASCÓ; ANDREAS ZIMMER; LILIANA CANCELA

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

ehavioral sensitization to cocaine is associated to neuroadaptations that contribute to addiction. Enkephalin is highlyexpressed in mesocorticolimbic areas associated with cocaine-induced sensitization; however, their influence oncocaine-dependent behavioral and neuronal plasticity has not been explained. In this study, we employed a knockout(KO) model to investigate the contribution of enkephalin in cocaine-induced behavioral sensitization.Wild-type (WT)and proenkephalin KO mice were treated with cocaine once daily for 9 days to induce sensitization. Additionally, toclarify the observations in KO mice, the same procedure was applied in C57BL/6 mice, except that naloxone wasadministered before each cocaine injection. All animals received a cocaine challenge on days 15 and 21 of thetreatment to evaluate the expression of locomotor sensitization. On day 21, microdialysis measures of accumbalextracellular dopamine, Western blotting for GluR