Influence of pulsed electromagnetic field with different pulse duty cycles on neurite outgrowth in PC12 rat pheochromocytoma cells

Abstract

The influence of low frequency (50 Hz repetition rate) pulsed electromagnetic field (EMF) on PC12 cell neurite outgrowth in vitro was investigated in this study. We studied the percentage of neurite bearing cells, average length of neurites, and directivity of neurite outgrowth in PC12 cells cultured for 96 h in the presence of nerve growth factor (NGF). PC12 cells were exposed in one incubator to pulsed EMF at 1.36 mT (peak value) generated by a pair of Helmholtz coils, and the control samples were placed in another identical incubator. We found that the pulse duty cycle had significant effect on neurite outgrowth. Low (10%) pulse on-time significantly inhibited the percentage of neurite bearing cells, but at the same time increased the average length of neurites, while 100% on-time (DC) had exactly the opposite effects. Furthermore, we found that neurites were prone to extend along the direction of pulsed EMF with 10% pulse on-time. Our studies show that neurite outgrowth in PC12 cells is sensitive to the pulse duty and this sensitivity was associated with NGF concentration.

Effects of 60-GHz millimeter waves on neurite outgrowth in PC12 cells using high-content screening

“…However, our particular exposure conditions may be an explanation, as previous works were assessing the impact of lower frequencies. Moreover, we used continuous waves, and it is possible that a modulated or pulsed electromagnetic signal is required to observe an impact on neurite outgrowth [38]. Very few work has been done using MMW and neuronal models.…”

Alimentary hyperlipemia of rabbits is affected by exposure to low‐intensity pulsed magnetic fields

“…Since the first application of PMFs produced by a pair of Helmholtz coils across a fracture site to enhance osteogenesis [Bassett, 1982], numerous studies have investigated the effects of PMFs on bones [Diniz et al, 2002;Chang and Chang, 2003;Chang et al, 2004], skin [Ieran et al, 1990;Milgram et al, 2004], and nerves [Zhang et al, 2005]. It has been theoretically inferred that PMFs, amongst the whole range of magnetic fields, may be more bioactive on biological processes [Panagopoulos et al, 2002], confirming the findings that the greatest effects seem to occur with onset or removal of continuous electromagnetic fields [Cook et al, 1992;Goodman et al, 1992Goodman et al, , 1995.…”

Short‐duration, DC electrical stimulation increases chick embryo DRG neurite outgrowth

“…Various methods of treating nerve injury include the application of electric and magnetic guidance cues to encourage and direct regeneration. Electrical fields (EFs) and pulsed electromagnetic fields (PEMFs) have been found to improve repair of nerve injuries in vivo [Borgens, 1988;Sisken et al, 1989;Borgens et al, 1999;Al-Majed et al, 2000] and enhance neuronal development by aligning and increasing neurite outgrowth in vitro [Jaffe and Poo, 1979;Patel and Poo, 1982;Erskine and McCaig, 1995;Greenebaum et al, 1996a;Schmidt et al, 1997;Macias et al, 2000;McCaig et al, 2000;Zhang et al, 2005]. Although this enhanced neural behavior is encouraging, further work is needed to fully understand and characterize the effects of field stimulation on neural tissue.…”