Differential expression of sodium channels and nicotinic acetylcholine receptor channels in nnr variants of the PC12 pheochromocytoma cell line

Ion channel expression differs between wild-type PC12 cells and nnr variants in the rat pheochromocytoma PC12 cell model. The study uses electrophysiological and molecular approaches to compare voltage-dependent sodium (Na) channels and nicotinic acetylcholine receptors (nAChRs) across nnr mutants versus wild-type cells. nnr cells express functional voltage-dependent Na channels and Na channel mRNA even without nerve growth factor (NGF), at levels higher than NGF-differentiated wild-type PC12 cells. By contrast, acetylcholine-induced currents appear in only a small fraction of nnr cells, suggesting that the nnr mutations alter the pattern of nAChR subunit mRNA expression. These channel-expression differences support using nnr variants as a tool to study Na channel and nAChR function and to identify mechanisms that control their expression during neuronal differentiation.