“…Several authors have shown that cells obtained from human pheochromocytoma are readily recognized as polygonal, dark-phase epithelial-like cells that usually form clusters and give rise to thin, branching, varicose processes of varying degrees similar to those of cultured neurons (Tischler et al, 1976(Tischler et al, , 1984Jaques and Tobes, 1986). Even though we used a different isolation protocol, similar cell populations to the ones described by these authors were obtained: a) cells firmly attached to the surface of the plate, with branched processes appearing with the progression of the culture, and b) round dark-phase cells in suspension.…”