title: β1-Adrenergic receptors activate two distinct signaling pathways in striatal neurons.
abstract: Monoamine action in the dorsal striatum and nucleus accumbens plays essential roles in striatal physiology. Although research often focuses on dopamine and its receptors, norepinephrine (NE) and adrenergic receptors are also crucial in regulating striatal function. While noradrenergic neurotransmission has been identified in the striatum, little is known regarding the signaling pathways activated by β-adrenergic receptors in this brain region. Using cultured striatal neurons, we characterized a novel signaling pathway by which activation of β1-adrenergic receptors leads to the rapid phosphorylation of cAMP response element binding protein (CREB), a transcription-factor implicated as a molecular switch underlying long-term changes in brain function. NE-mediated CREB phosphorylation requires β1-adrenergic receptor stimulation of a receptor tyrosine kinase, ultimately leading to the activation of a Ras/Raf/MEK/MAPK/MSK signaling pathway. Activation of β1-adrenergic receptors also induces CRE-dependent transcription and increased c-fos expression. In addition, stimulation of β1-adrenergic receptors produces cAMP production, but surprisingly, β1-adrenergic receptor activation of adenylyl cyclase was not functionally linked to rapid CREB phosphorylation. These findings demonstrate that activation of β1-adrenergic receptors on striatal neurons can stimulate two distinct signaling pathways. These adrenergic actions can produce long-term changes in gene expression, as well as rapidly modulate cellular physiology. By elucidating the mechanisms by which NE and β1-adrenergic receptor activation affects striatal physiology, we provide the means to more fully understand the role of monoamines in modulating striatal function, specifically how NE and β1-adrenergic receptors may affect striatal physiology.
authors.affiliation: Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, USA. meitz010@umn.edu
authors.forename: John
authors.initials: J
authors.lastname: Meitzen
authors.forename: Jessie I
authors.initials: JI
authors.lastname: Luoma
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Stern
authors.forename: Paul G
authors.initials: PG
authors.lastname: Mermelstein
mesh_terms: D018663:Adrenergic Agents / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D050882:CREB-Binding Protein / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D003342:Corpus Striatum / Q000166:cytology*; D000242:Cyclic AMP / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*
chemical_list: D018663:Adrenergic Agents; D002614:Chelating Agents; D004791:Enzyme Inhibitors; C489787:MAP2 protein, rat; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D018342:Receptors, Adrenergic, beta-1; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D000242:Cyclic AMP; D050882:CREB-Binding Protein; D020794:Receptor Protein-Tyrosine Kinases; D009638:Norepinephrine