The structure and development of a somatotopic map in crickets: The cercal afferent projection☆
[摘要] Agroupofclub-shapedsensillacalledclavatehairs,locatedonthecercusofcrickets(Achetadomesticus),arepartofaspecializedsensorysystemwhichmonitorstheorientationofacricketwithrespecttotheearth'sgravitationalfield.Theclavatehairsoccurinrowswhichrunproximodistallyonthemedialaspectofthecercusandeachhaircanbeidentifiedbyspecifyingwhichrowahairisinandwhatpositionitisinwithintherow.Thearrayofhairsisconstantfromindividualtoindividual,andthuseachhaircanbeidentifiedineachspecimen.Thesomaofasinglebipolarsensoryneuronislocatedintheintegumentbeloweachhair;itsdendriteprojectsintothehairanditsaxonprojectstoawell-definedareaoftheabdominalganglioncalledthecercalglomerulus.Alloftheneuronswithinarowprojecttoaparticularareaofthecercalglomerulusanddifferentrowsprojecttodifferentareaswithintheglomerulus.Withinarowneuronsprojecttoslightlydifferentpartsofthetargetareaforthatrow.Thusahighlyorderedprojectionpatternisproducedwhichistentativelycalledsomatotopic.Thedevelopmentofthefirstclavateneurontoappearwasexaminedfromthefirstinstartotheadultinstar.Theterminalarborizationofthisfirsthairwasinnowayunusualanditsgrowthparalleledgangliongrowth,maintainingarelativelyconstantpositionwithrespecttoganglioncoordinates.Asecondclavateneuronbehavedsimilarly,itsarborizationwasfullyformedwhenthereceptorfirstappearedinthethirdinstarandmerelyenlargedasthegangliongrew.
[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]
