Quantitative effects of laminin concentration on neurite outgrowth in vitro☆

[摘要] Recentstudiesindicatethatmediationofneuriteoutgrowthbytheglycoproteinlamininmaybeasignificantfactorintheoutgrowthofneuritestotheirtargetsduringembryogenesis.Tofurthercharacterizethepossibleroleofthisextracellularmatrixmoleculeduringdevelopment,wehavesystematicallymeasuredseveralfeaturesofoutgrowthbyneonatalratsympatheticneuronsondifferentconcentrationsoflaminin.Individualneurons,obtainedbymechanicaldissociationofsuperiorcervicalganglia(SCG),wereculturedatlowdensityonlamininsubstratesrangingfrom0.01to1.0μg/cm2.Outgrowthcharacteristicsweresubsequentlyanalyzedfornoninteractingcellsinbothfixedandlivecultures.Dataobtainedfromneuronsfixedafter11hrofcultureshowedapproximatelytwofoldincreasesinneuriteinitiationandoutgrowth,andatwofolddecreaseinbranchingforacorresponding100-foldincreaseinadsorbedlamininconcentration.Intime-lapsevideomicroscopyobservations,theroot-meansquarespeedofgrowthconemovementincreasedfrom60to90μm/hroverthesamerangeinconcentration,whilethepersistencetimeremainedconstantat0.10hr.Ingeneral,neuriteoutgrowthparameterswererelativelyinsensitivetochangesinlamininconcentration,supportingtheideathatlamininisapermissiveratherthanan“instructive”substrateduringdevelopment.Dataobtainedfromfixedcultureswereexaminedintermsofprobabilitymodelstosuggestpossiblemechanismscontributingtothedose-dependenteffectsobserved.

[学科分类] 生物科学（综合）