Microwave‐induced changes in nerve cells: Effects of modulation and temperature

Abstract

Helix aspersa neurons were irradiated with continuous‐wave (CW) and noise‐amplitudemodulated microwaves (carrier frequency 2450 MHz, 20% AM, 2 Hz‐20 kHz) in a specially designed waveguide exposure system. Continuous‐wave microwave irradiations were conducted at 8°, 21°, and 28°C, while noise‐modulated irradiation was performed at 21°C. The results showed that exposure of snail neurons to CW microwaves for 60 min at 12.9 W/kg inhibited spontaneous activity and reduced input resistance at 8° and 21°C but not at 28°C. The relative decrease in resistance at 21°C was half that at 8°C. Exposure of neurons to noise‐modulated microwaves at 6.8 and 14.4 W/kg predominately caused excitatory responses characterized by augmented membrane resistance and the appearance of greater activity. The effect differed qualitatively from the inhibition observed with continuous, unmodulated microwave irradiation.