Development of the dendritic branching pattern of the Medial Giant Interneuron in the grasshopper embryo☆
[摘要] Theembryonicdevelopmentofthegrasshopper'sMedialGiantInterneuron(MGI)wasexaminedbyinjectingthecellwiththefluorescentdyeLuciferYellowataseriesofstagesinitsgrowth.Particularattentionwasgiventothewayinwhichthisneuronconstructsitsstereotypeddendriticbranchingpattern.TheMGI'sdendritesoriginateassecondaryprocesseswhichsproutatcharacteristicpointsalongtheneuriteaftertheprimarygrowthconehaspassed.Theseprocessesthenarborizetoformaminiatureversionoftheiradultbranchingpatternbeforetheendofembryoniclife.Whilegrowing,thedendriticbranchesarecoveredwitharadiantprofusionoffilopodia;however,thesefilopodiaareephemeralstructuresanddisappearoncethecellmatures.Bycontrastthereisnosignificantreductionineitherthenumberorthespatialextentoftheactualdendritesatanyembryonicstage.ThisimpliesthatthestereotypedbranchingpatternofthematureMGIisprimarilydeterminedbyaprecisepatternofinitialgrowth,andthatsecondarypruningofbranchesdoesnotplayanimportantroleinshapingthefinalformofthiscell.Thecoordinateingrowthofthefirstcercalsensoryaxonswasexaminedbycobaltfillingtheembryonicnerve,andthemeansbywhichthesesensoryaxonsmaketheirinitialcontactswiththeMGI'sdendritesishereindiscussed.Thefollowingpaperconsidersthedegreetowhichthissensoryinnervationregulatesdendriticgrowthandbranching.
[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]
