ID Number		1579
Study Type		In Vitro
Model		Development of two exposure systems for the measurement of retinal ganglion cell responses to light under the influence of pulsed HF EMF [GSM (900, 1800 MHz)and UMTS (1966 MHz)].
Details		Isolated mouse retinal ganglion cells were exposed to 900 MHz (GSM) and 1800 MHz (UMTS) for 30 minutes at 0.02, 0.2, 2, and 20 W/kg and measured for changes in response rate, action potential, and latency period in response to a light stimuli (ON and OFF) at different light intensities. The temperature of the perfusion solution surrounding the retina was maintained at 37 degrees. Separate experiments were performed to determine the effects of temperature alone. Multiple means comparisons (>300 Dunnetts t-tests) and the general lineal model statistical analyses suggested some significant differences. However, the overall data indicated that the response of radiofrequency radiation-exposed cells did not differ significantly and systematically from the sham-exposed cells. Temperature increase alone induced increased response rate and decreased latency periods. A unique waveguide exposure system was also developed that exposed isolated and perfused intact retina cultures (photo-recepter side down) to 800 MHz (GSM) or 1800 MHz (GSM, UMTS) at 0.02, 0.2, 2, and 20 W/kg at constant temperature with simultaneous light flashes (200 msec duration at a repetition rate of 0.5 Hz). The authors report exposure at 0.2 W/kg or above blocked regular action potentials from the light stimulus. The authors suggest that since both UMTS and GSM contain low frequency modulation components in the same range as neuronal action potentials (e.g., 1000 Hz), this acts to interfere with the normal retinal response to light. AUTHORS' ABSTRACT: Ahlers et al. 2009 (IEEE #4149): Two exposure systems were developed for the measurement of retinal ganglion cell responses to light under the influence of pulsed high-frequency electromagnetic fields. Exposure characteristics were determined numerically for the GSM standards (900/1,800 MHz) and the UMTS standard (1,966 MHz) with specific absorption rates, averaged over the region of interest, of 0.02, 0.2, 2 und 20 W kg(-1). Extracellular multi- and single unit recordings of light responses from several retinal ganglion cells per retina could be obtained in these exposure systems on a regular basis, using two recording electrodes simultaneously. With appropriate temperature control adjustment, maximal temperature deviations at exposure onset and offset were well below the range of +/-0.1 degrees C for all SAR values.
Findings		Effects (preliminary results only)
Status		Completed With Publication
Principal Investigator		University of Oldenburg, Germany
Funding Agency		BfS, Germany, DMF, Germany
Country		GERMANY
References		Ahlers, MT et al. Radiat Environ Biophys., (2009) 48:227-235
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