Class-IV neuronal intermediate filament that is able to self- assemble. It is involved in the morphogenesis of neurons. It may form an independent structural network without the involvement of other neurofilaments or it may cooperate with NEFL to form the filamentous backbone to which NEFM and NEFH attach to form the cross-bridges. May also cooperate with the neuronal intermediate filament protein PRPH to form filamentous networks (By similarity). . This is the function of ENSG00000148798 (INA, internexin neuronal intermediate filament protein alpha).