Effects of pulsed magnetic stimulation on GFAP levels in cultured astrocytes

The present study evaluates the physiological effects of magnetic stimulati on on astrocyte cultures. Cell cultures were exposed to pulsed magnetic sti mulation (10 Hz, 10 sec) at the following levels: 0.10 tesla (T; Group A); 0.21 T (Group B); 0.42 T (Group C); and 0.63 T (Group D), Glial fibrillary acidic protein (GFAP) levels from immunoblots, total protein concentrations , and cellular morphology were analyzed at 0, 1, 3, 5, 7, 13, and 20 days p oststimulation, Significantly higher GFAP levels were observed in Group D a t day 3 (P = 0.0114), The change was transient as the GFAP levels quickly r eturned to control levels by day 5, No other significant changes in GFAP le vels were observed. In comparison to control protein levels at day 0, conce ntrations from Groups B, C, and D were significantly lower (P < 0.006), whe reas at day 3, Groups C and D were significantly higher (P < 0.02), Differe nces in astrocyte morphology due to magnetic stimulation were not observed. This study demonstrated that high intensity magnetic stimulation for only 10 sec induced a transient biological response. J. Neurosci, Res. 55:238-24 4, 1999. Published 1999 Wiley-Liss, Inc.(dagger)