Magnetic fields at resonant conditions for the hydrogen ion affect neurite outgrowth in PC-12 cells: A test of the ion parametric resonance model
✍ Scribed by María A. Trillo; Alejandro Ubeda; Janie P. Blanchard; Dennis E. House; Carl F. Blackman
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 982 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0197-8462
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✦ Synopsis
PC-12 cells primed with nerve growth factor (NGF) were exposed to sinusoidal extremely-low-frequency (ELF) magnetic fields (MFs) selected to test the predictions of the ion parametric resonance (IPR) model under resonance conditions for a single ion (hydrogen). We examined the field effects on the neurite outgrowth (NO) induced by NGF using three different combinations of flux densities of the parallel components of the AC MF (Bat) and the static MF (Bd,). The first test examined the NO response in cells exposed to 45 Hz at a Bdc of 2.96 pT with resonant conditions for H' according to the model. The BaC values ranged from 0.29 to 4.1 1 pT root-mean-square (rms). In the second test, the MF effects at off-resonance conditions (i.e., no biologically significant ion at resonance) were examined using the frequency of 45 Hz with a Bdc of 1.97 pT and covering a BaC range between 0.79 and 2.05 pT rms. In the third test, the AC frequency was changed to 30 Hz with the subsequent change in Bdc to 1.97 pT to tune for H' as in the first test. The BaC values ranged from 0.79 to 2.05 pT rms. After a 23 h incubation and exposure to the MF in the presence of NGF (5 ng/ml), the NO was analyzed using a stereoscopic microscope. The results showed that the NGF stimulation of neurite outgrowth (NSNO) was affected by MF combinations over most of the BaC exposure range generally consistent with the predictions of the IPR model. However, for a distinct range of BaC where the IPR inodel predicted maximal ionic influence, the observed pattern of NSNO contrasted sharply with those predictions. The symmetry of this response suggests that values of BaC within this distinct range may trigger alternate or additional cellular mechanisms that lead to an apparent lack of response to the MF StimUluS. 01996 Wiley-Liss, Inc.