Neuronal differentiation of chromaffin cells in vitro, induced by extremely low frequency magnetic fields or nerve growth factor: A histological and ultrastructural comparative study

Abstract

The application of nerve growth factor (NGF) to primary adrenal medulla chromaffin cell cultures induces phenotypic changes characterized mainly by the presence of neurites. A similar effect has been seen when these cells are stimulated by extremely low frequency magnetic fields (ELFMF). In this study, newborn rat chromaffin cells were cultured and subjected to NGF or ELFMF in order to compare their histological and ultrastructural characteristics. Cells cultured in the presence of NGF developed cytoplasmic projections and their distal ends showed growth cones as well as filopodia. With scanning and transmission electron microscopy, an increased submembranous electron density was observed in the nuclei of cells as well as irregular, wavy neuritic projections with a moderate number of varicosities, as well as the prevalence of intermediate filaments among the cytoskeleton components. Cells stimulated with ELFMF presented straighter neuritic extensions with a greater number of varicosities. With the transmission electron microscope, numerous neurotubules were observed, both in the cell soma and in their neuritic extensions. In both groups, growth cones were clearly identified by their ultrastructural characteristics. The differences seen in the cytoskeleton of cells stimulated with NGF or ELFMF suggest differential stimulation mechanisms possibly determining the biochemical, electrophysiological, and morphological characteristics in both types of cell cultures.

Ultrastructural changes in pancreatic beta cells treated with NGF and dbcAMP

“…The same type of phenotypic changes observed in β-cells treated with NGF and/or dbcAMP has been described in the PC12 cell line and in chromaffin cells from the adrenal medulla (Shubert and Whitlock 1977;Pacheco-Cano et al 1990;Feria-Velasco et al 1998). However, the latency for this morphological response is longer for β-cells than for PC12 cells.…”

Neurogenesis in the subventricular zone following transcranial magnetic field stimulation and nigrostriatal lesions

“…Magnetic fields (MF) can influence biological systems by generating electrical fields, changing diffusion across membranes, exerting force on charged carriers and magnetic dipoles, and catalyzing reactions involving free radicals (Levin, 2003). Neurite outgrowth and neuronal differentiation of CCs, both in vitro and in vivo, are induced by MF stimulation (Drucker‐Colin et al, 1994; Feria‐Velasco et al, 1998). It is known that endogenous bioelectromagnetic fields convey morphogenetic information for embryonic development and regeneration (for reviews see Levin, 2003; Nuccitelli, 2003).…”

“…Animals showed no signs of discomfort when exposed to TMFS. The daily time of exposure to TMFS was selected on the basis of our previous reports demonstrating in vitro neuronal differentiation of CCs (Drucker‐Colín et al, 1994; Feria‐Velasco et al, 1998). The length of in vivo exposure was determined on the basis of preliminary experiments indicating 60 days of TMFS as optimal (Verdugo‐Díaz and Drucker‐Colín, unpublished observations).…”

Alterations in TSH and Thyroid Hormones following Mobile Phone Use

“…8 Regarding the endocrine system, the sensitivity of pineal gland, pituitary gland, adrenal gland and thyroid gland as well as of the endocrine pancreas, testicles and ovaries to EMFs have been investigated. [9][10][11][12][13][14][15][16][17][18][19][20][21] The thyroid gland is one of the most exposed and vital organs and may be a target for any type of electromagnetic radiation. 22 It has been established that even a small change in thyroid hormone levels circulating in the blood are sufficient to alter the brain function of subjects.…”