The genesis and transmission of epidermal potentials in an amphibian embryo☆
[摘要] Thegenesisandtransmissionofactionpotentialsinepidermalcellsofthenewt(Cynopspyrrhogaster)embryowereinvestigatedwithspecialreferencetocellulardifferentiationduringdevelopment.TypicalactionpotentialscanberecordedfromanyoftheepidermalcellsatStage31.Thesepotentialsconsistofafastspike(18msec)followedbyaslowcomponent(164msec).Thepotentialisgradedwithcurrentintensity,andonlytheslowcomponentinitiatesactionpotentialsinadjacentcellsandinducesatransmissiontoothercells.Thefastspikewasfoundinallepidermalcellsthroughouttheembryonicstagesexamined(Stages26–47).Theslowpotential,however,appearsatStage28,persistsuntilStage3637justbeforehatchingandthendisappearsatStage3842.Electricalrecordingsfromtraumaticembryos(embryoswithoutneuralcrestcells)orfromculturedepidermalcellmassesisolatedfromthepregastrulaortheventralregionoftheneurula,werecomparedwiththeintactembryo.Nodifferenceswereobservedineithertheformoftheactionpotentialoritstransmission.Thustheseactionpotentialsappeartobederivedfromepidermalcells,andarenotofnervousorigin.Evidencesuggeststhatthetransientestablishmentofexcitablemembranesinepidermalcellsduringdifferentiationiscloselyrelatedtoneuralcelldifferentiation.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
