title: A neural influence on the appearance of sodium current in Xenopus embryonic myocytes.
abstract: Regulation of early embryonic expression of sodium current in cultured Xenopus laevis myocytes was investigated. In myocytes isolated before innervation and cultured for about 1 day, only 51% expressed sodium current at a mean density of 74 +/- 20 pA/pF (mean +/- SEM; n = 26), inadequately reflecting the functional development of skeletal muscle in vivo at this time. This cell-autonomous expression pattern could be modulated. First, co-culture of myocytes and dissociated neural tissue induced additional sodium current expression (82%; 172 +/- 31 pA/pF, n = 14) and, secondly, removal of calcium from the culture medium reduced sodium current density (13 +/- 6 pA/pF; n = 5). The former results suggest that a diffusible factor released from differentiating neurons is able to initiate the expression of sodium channels in myocytes.
authors.affiliation: Department of Pharmacology, Medical School, University of Birmingham, Edgbaston, UK.
authors.forename: E
authors.initials: E
authors.lastname: Prabhakar
authors.forename: T
authors.initials: T
authors.lastname: Barnes
authors.forename: A E
authors.initials: AE
authors.lastname: Spruce
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000502:physiology; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development*; D009474:Neurons / Q000502:physiology*; D015222:Sodium Channels / Q000502:physiology*; D014981:Xenopus
chemical_list: D015222:Sodium Channels