RT Journal Article
SR Electronic
T1 Behavioral and Structural Responses to Chronic Cocaine Require a Feedforward Loop Involving ΔFosB and Calcium/Calmodulin-Dependent Protein Kinase II in the Nucleus Accumbens Shell
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4295
OP 4307
DO 10.1523/JNEUROSCI.5192-12.2013
VO 33
IS 10
A1 Alfred J. Robison
A1 Vincent Vialou
A1 Michelle Mazei-Robison
A1 Jian Feng
A1 Saïd Kourrich
A1 Miles Collins
A1 Sunmee Wee
A1 George Koob
A1 Gustavo Turecki
A1 Rachael Neve
A1 Mark Thomas
A1 Eric J. Nestler
YR 2013
UL http://www.jneurosci.org/content/33/10/4295.abstract
AB The transcription factor ΔFosB and the brain-enriched calcium/calmodulin-dependent protein kinase II (CaMKIIα) are induced in the nucleus accumbens (NAc) by chronic exposure to cocaine or other psychostimulant drugs of abuse, in which the two proteins mediate sensitized drug responses. Although ΔFosB and CaMKIIα both regulate AMPA glutamate receptor expression and function in NAc, dendritic spine formation on NAc medium spiny neurons (MSNs), and locomotor sensitization to cocaine, no direct link between these molecules has to date been explored. Here, we demonstrate that ΔFosB is phosphorylated by CaMKIIα at the protein-stabilizing Ser27 and that CaMKII is required for the cocaine-mediated accumulation of ΔFosB in rat NAc. Conversely, we show that ΔFosB is both necessary and sufficient for cocaine induction of CaMKIIα gene expression in vivo, an effect selective for D1-type MSNs in the NAc shell subregion. Furthermore, induction of dendritic spines on NAc MSNs and increased behavioral responsiveness to cocaine after NAc overexpression of ΔFosB are both CaMKII dependent. Importantly, we demonstrate for the first time induction of ΔFosB and CaMKII in the NAc of human cocaine addicts, suggesting possible targets for future therapeutic intervention. These data establish that ΔFosB and CaMKII engage in a cell-type- and brain-region-specific positive feedforward loop as a key mechanism for regulating the reward circuitry of the brain in response to chronic cocaine.