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

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.

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 (2x70 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).

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 H(2)O(2) 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.

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