title: Interplay between electrical activity and bone morphogenetic protein signaling regulates spinal neuron differentiation.
abstract: A gradient of bone morphogenetic proteins (BMPs) along the dorsoventral axis of the spinal cord is necessary for the specification of dorsal neurons. Concurrently, a gradient of calcium-mediated electrical activity is present in the developing spinal cord but in an opposing ventrodorsal direction. Whether BMPs and electrical activity interact in embryonic spinal neurons remains unknown. We show that BMP decreases electrical activity by enhancing p38 MAPK-mediated negative modulation of voltage-gated sodium channels. In turn, electrical activity affects the phosphorylation status and nuclear level of activated Smads, the canonical components of BMP signaling. This interaction between calcium spike activity and BMP signaling regulates the specification of the dorsal commissural spinal neuron phenotype. The present study identifies an unexpected interplay between BMPs and electrical activity that is critical for decoding the morphogen gradient during spinal neuron differentiation.
authors.affiliation: Department of Physiology and Membrane Biology, Shriners Hospital for Children Northern California, University of California at Davis School of Medicine, Sacramento, CA 95817, USA.
authors.forename: Immani
authors.initials: I
authors.lastname: Swapna
authors.forename: Laura N
authors.initials: LN
authors.lastname: Borodinsky
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D007395:Interneurons / Q000378:metabolism / Q000502:physiology*; D018613:Microscopy, Confocal; D010766:Phosphorylation; D051785:Smad Proteins / Q000378:metabolism; D013127:Spinal Nerves / Q000166:cytology*; D009435:Synaptic Transmission / Q000502:physiology*; D061566:Voltage-Gated Sodium Channels / Q000378:metabolism; D014981:Xenopus / Q000196:embryology* / Q000378:metabolism; D000099176:Noggin Protein
chemical_list: D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D051785:Smad Proteins; D061566:Voltage-Gated Sodium Channels; D000099176:Noggin Protein