The increasing use of mobile phones over the last years lead to an increased public concern with respect to possible health risks involved. During use, most of the energy of mobile phone communcation signals is directly absorbed by the area around the ear. We therefore investigated whether mobile phone field exposure affected voltage-activated L-type Cav1.3 Ca2+ currents in mouse inner hair cells. This Ca2+ channel is driven by the receptor potential, triggers exocytosis via Ca2+ influx and thus plays a crucial role in the signal transduction of inner hair cells. Using the whole-cell patch-clamp configuration Ba2+ currents through Ca2+ channels were measured for 5 min prior to an exposure, during a 20 min exposure phase and for 15 min after exposure (40 min measurement time) under randomized blinded exposure conditions for SAR values of 0.02, 0.2, 2, 20 W/kg and sham. Two different exposure signal types simulating GSM 1800 and UMTS communication signals were used. The following parameters were extracted from the data: maximum current, voltage of half-activation, steepness of activation, series- resistance and leak-resistance. Currently, data are being statistically analyzed and unblinded to provide evidence whether the exposure with mobile phone communication fields has any influence on the Ca2+ channel currents.

Supported by BMU/ Bundesamt fuer Strahlenschutz StSch-4427