BackgroundInformation | NeurofilamentsareatypeofintermediatefilamentthatserveasmajorelementsoftheCytoskeletonsupportingtheaxoncytoplasm.Theyarethemostabundantfibrillarcomponentsoftheaxon,beingonaverage3-10timesmorefrequentthanaxonalmicrotubules.Neurofilaments(10nmindia.)arebuiltfromthreeintertwinedprotofibrilswhicharethemselvescomposedoftwotetramericprotofilamentcomplexsofmonomericproteins.Theneurofilamenttripletproteins(68/70,160,and200kDa)occurinboththecentralandperipheralnervoussystemandareusuallyneuronspecific.The68/70kDaNF-Lproteincanself-assembleintoafilamentousstructure,howeverthe160kDaNF-Mand200kDaNF-Hproteinsrequirethepresenceofthe68/70kDaNF-Lproteintoco-assemble.Neuromas,ganglioneuromas,gangliogliomas,ganglioneuroblastomasandneuroblastomasstainpositivelyforneurofilaments.Althoughtypicallyrestrictedtoneurons,neurofilamentshavebeendetectedinparagangliomasandadrenalandextra-adrenalpheochromocytomas.Carcinoids,neuroendocrinecarcinomasoftheskin,andoatcellcarcinomasofthelungalsoexpressneurofilaments. |