Primer sequences: NT3 forward 5′-CTGCCACGATCTTACAGGTG-3′, NT3 reverse 5′-TCCTTTGATCCATGCTGTTG-3′, MyoD forward 5′-GGCTACGACACCGCCTACTA-3′, MyoD reverse 5′-CACTATGCTGGACAGGCAGT-3′.

We thank Andy Liu and Ira Schieren for technical help, Barbara Han, Susan Brenner-Morton, click here Monica Mendelsohn, and Jennifer Kirkland for help with generation of antibodies and mouse strains, Neil Shneider for providing the hEGR3 promoter construct and information on its MS expression, and Stéphane Nédelec and Annina DeLeo for advice on qRT-PCR experiments. We are grateful to S. Arber, D. Wright, W. Snider, and S. Dufour for mouse strains, and to Eiman Azim, Jay Bikoff, Nikolaos Balaskas, George Mentis, Sebastian Poliak, and Niccoló Zampieri for comments on the manuscript. J.C.N. was supported by a Helen Hay Whitney Foundation fellowship. T.M.J. was supported by NIH grant NS033245, the Harold and Leila Y. Mathers Foundation, and Project A.L.S. T.M.J. is an HHMI Investigator. “
“A neuron’s ability to elicit and propagate electric signals is determined KU-55933 cell line intrinsically by its membrane properties including the resting membrane potential (RMP)

(Hille, 2001). Neuronal RMP is established by the sodium (Na+)/potassium (K+) pump and background K+ channels (Nicholls et al., 2001) and maintained by a persistent Na+ permeability (Crill, 1996; Hodgkin and Katz, 1949). NALCN, the pore-forming α subunit of a newly defined four domain ion channel, accounts for a fraction of the tetrodotoxin-resistant, gadolinium (Gd3+)-sensitive Na+ leak that depolarizes RMP and potentiates action potential firing in mouse hippocampal neurons (Lu et al., 2007). While NALCN shares considerable sequence homology to voltage-gated Na+ and Ca2+ channels, it bears key amino acid differences. Most notably, it has a reduced number of negatively charged amino acids in the voltage-sensing S4 transmembrane all segments, and its ion selectivity motif also deviates from the classic Na+ and Ca2+ filters (Catterall, 2000a, 2000b). In vivo, the neuronal NALCN channel contributes to the Na+ leak current

at rest, and is potentiated upon the activation of neurotensin and substance P receptors (Lu et al., 2009). In pancreatic β cell lines, NALCN’s activity contributes to an inward Na+ current coupled with the activation of M3 muscarinic receptors (Swayne et al., 2009). In parallel, putative invertebrate NALCN homologs were discovered in C. elegans ( Humphrey et al., 2007; Jospin et al., 2007; Yeh et al., 2008) and Drosophila ( Lear et al., 2005; Nash et al., 2002) and recently in snail ( Lu and Feng, 2011). Previously, we and others showed that two C. elegans NALCN homologs, NCA-1 and NCA-2, function redundantly to affect C. elegans locomotion ( Jospin et al., 2007; Pierce-Shimomura et al., 2008; Yeh et al., 2008). Wild-type C. elegans travels on a culture plate through the continuous and rhythmic propagation of sinusoidal body bends (see Movie S1A available online).