Band 1 and voltage-sensitive Na channels are not codistributed in cultured rodent neuronal cells

The relationship of the mouse nervous system specific band 1 protein to the putative high molecular weight component of the Na+ channel was investigated using antibody to band 1. Morphologic differentiation of cultured neuroblastoma cells has been reported to increase the quantity of the putative Na+ channel high molecular weight component. Morphologically differentiated clone NB2a neuroblastoma cells have 2-3 times the amount of band 1 and 1.5 times the relative rate of synthesis of band 1 as undifferentiated cells. The anti-band 1 serum reacts with both adult mouse and rat brain but not 3 cultured rat neuronal lines known to have active Na+ channels. Thus either band 1 is not a component of the Na+ channel or individual cultured murine neuronal lines has distinct macromolecular Na+ channels.