COMPARISON BETWEEN LOW-FREQUENCY MAGNETIC-FIELD STIMULATION AND NERVEGROWTH-FACTOR TREATMENT OF CULTURED CHROMAFFIN CELLS, ON NEURITE GROWTH, NORADRENALINE RELEASE, EXCITABLE PROPERTIES, AND GRAFTING IN NIGROSTRIATAL LESIONED RATS

Adrenal chromaffin cells in vitro respond to nerve growth factor (NGF) by expressing neuronal traits. Low frequency magnetic (LFM) field sti mulation, while inducing a variety of effects on several cell types, h as never been studied as to its effects on chromaffin cell cultures. T he purpose of this study was to compare the effects of LFM field stimu lation with that of NGF on the morphological phenotype, on noradrenali ne (NA) release, and on membrane excitability of cultured chromaffin c ells. We also tested the effects of grafting LFM and NGF-treated chrom affin cells into the caudate nucleus of rats with 6-hydroxydopamine le sions of the nigrostriatal pathway. The results of this study showed t hat LFM field stimulation produced neurite growth of cultured chromaff in cells in a manner similar to that of NGF exposure. The combination of the two procedures did not induce changes above those observed by N GF alone. Both NGF- and LFM-treated chromaffin cells released [H-3]NA equally in response to a depolarizing concentration of KCl. On the oth er, Na+ current density of LFM field stimulation increased, but to a l esser extent than that seen in NGF-treated cells. In addition both typ es of cells when transplanted into nigrostriatal-lesioned animals indu ced a similar decrease in the motor asymmetries produced by the lesion . When NGF- or LFM-treated chromaffin cells where compared to untreate d control cells, no significant differences were observed in [H-3]NA r elease, on Na+ current densities, or on postgraft motor asymmetries. T he results are discussed in terms of the fact that LFM-stimulated cell s can be differentiated in a manner similar to NGF-treated cells, by a cquiring sympathetic like traits which in turn can diminish motor asym metries when grafted into nigrostriatal-lesioned rats. (C) 1994 Academ ic Press, Inc.