The aim of this work is the study of the effect of electromagnetic radiations (ELF-EMF) tuned to the calcium cyclotron resonance condition of 7.0 Hz, 9.2 microT on the differentiation process of pituitary corticotrope-derived AtT20 D16V cells. These cells respond to nerve growth factor by extending neurite-like processes. To establish whether exposure to the field could influence the molecular biology of the pituitary gland, a corticotrope-derived cells line (AtT20 D16V) was exposed to ELF-EMF at a frequency of 7.0 Hz, 9.2 microT electromagnetic field by a Vega Select 719 power supply. Significant evidence was obtained to conclude that as little as 36 h exposure to the Ca(2+) ICR condition results in enhanced neurite outgrowth, with early expression and aggregation of the neuronal differentiation protein NF-200 into neurite structures.