Repetitive transcranial magnetic stimulation does not influence immunological HL-60 cells and neuronal PC12 cells

Abstract

Background: Transcranial magnetic stimulation (TMS) is a non-invasive method used in medical applications such as brain mapping or as a therapeutic tool in neurological and psychiatric disorders because it can stimulate defined regions of the brain without anaesthesia.

Methods: The action of repetitive transcranial magnetic stimulation (rTMS) on HL-60 and PC12 cells has been investigated. The cells have been stimulated in vitro with different number of pulses (75 – 1250), different intensities (10, 20 and 40%) and different frequencies (0.25, 1 and 10 Hz) by using a double coil (2×70 mm) connected to the ‘Magstim rapid’. At selected time points after treatment the following endpoints have been determined: viability, cyclic AMP (cAMP) and heat shock protein 72 (Hsp72) (HL-60 cells), and viability, cAMP, dopamine and noradrenaline (PC12 cells). Viability was measured with the alamarBlue assay, whereas cAMP, Hsp72, dopamine and noradrenaline were determined with enzyme-linked immunosorbent assay (ELISA).

Results: In both cell lines viability was not influenced by rTMS treatment, the same was true for the cytosolic cAMP concentration. In HL-60 cells rTMS treatment did not change the Hsp72 content, also a protective effect of rTMS treatment on cell viability before toxic H₂O₂ treatment was not observed. After high potassium treatment the release of the two neurotransmitters dopamine and noradrenaline in PC12 cells was enhanced 15- and 5-fold, respectively, but after rTMS treatment no change in the release of the two neurotransmitters was observed.

Conclusions: In two mammalian cell lines rTMS treatment in a variety of exposure conditions does not influence any of the measured parameters.

Keywords:

• Repetitive transcranial magnetic stimulation
• HL-60 cells
• PC12 cells
• cell viability
• cyclic AMP
• neurotransmitter release
• heat shock proteins