title: A role for calmodulin-stimulated adenylyl cyclases in cocaine sensitization.
abstract: Cocaine sensitization is produced by repeated exposure to the drug and is thought to reflect neuroadaptations that contribute to addiction. Here, we identify the Ca(2+)/calmodulin-stimulated adenylyl cyclases, type 1 (AC1) and type 8 (AC8), as novel regulators of this behavioral plasticity. We show that, whereas AC1 and AC8 single knock-out mice (AC1(-/-) and AC8(-/-)) exhibit Ca(2+)-stimulated adenylyl cyclase activity in striatal membrane fractions, AC1/8 double-knock-out (DKO) mice do not. Furthermore, DKO mice are acutely supersensitive to low doses of cocaine and fail to display locomotor sensitization after chronic cocaine treatment. Because of the known role for the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase signaling pathway in cocaine-induced behavioral plasticity and its coupling to calcium-stimulated cAMP signaling in the hippocampus, we measured phosphorylated ERK (pERK) levels in the striatum. Under basal conditions, pERK is upregulated in choline acetyltransferase-positive interneurons in DKO mice relative to wild-type (WT) controls. After acute cocaine treatment, pERK signaling is significantly suppressed in medium spiny neurons (MSNs) of DKO mice relative to WT mice. In addition to the lack of striatal ERK activation by acute cocaine, signaling machinery downstream of ERK is uncoupled in DKO mice. We demonstrate that AC1 and AC8 are necessary for the phosphorylation of mitogen and stress-activated kinase-1 (pMSK1) at Ser376 and Thr581 and cAMP response element-binding protein (pCREB) at Ser133 after acute cocaine treatment. Our results demonstrate that the Ca(2+)-stimulated adenylyl cyclases regulate long-lasting cocaine-induced behavioral plasticity via activation of the ERK/MSK1/CREB signaling pathway in striatonigral MSNs.
authors.affiliation: Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Derek P
authors.initials: DP
authors.lastname: DiRocco
authors.forename: Zachary S
authors.initials: ZS
authors.lastname: Scheiner
authors.forename: Carlos Balet
authors.initials: CB
authors.lastname: Sindreu
authors.forename: Guy C-K
authors.initials: GC
authors.lastname: Chan
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Storm
mesh_terms: D000262:Adenylyl Cyclases / Q000172:deficiency / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D050882:CREB-Binding Protein / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism; D003042:Cocaine / Q000008:administration & dosage*; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013912:Threonine / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics
chemical_list: D002147:Calmodulin; D018765:Dopamine Uptake Inhibitors; D013912:Threonine; D012694:Serine; D050882:CREB-Binding Protein; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C116919:mitogen and stress-activated protein kinase 1; D017868:Cyclic AMP-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1; C118292:adenylyl cyclase 8; D003042:Cocaine; D002118:Calcium