Dynamics and Infradian Rhythmics of Thermal/Pain Sensitivity of the Helix Mollusc under the Action of Electromagnetic Fields

We measured characteristics of thermal/pain (th/p) sensitivity of Helix albescens (threshold and latency of the avoidance behavioral reaction) under conditions of the hot-plate test. As was found, weakening (shielding) of the background electromagnetic field, as well as the action of low-intensity radiations of extremal-frequency ranges, induced two-phase changes of these characteristics within a 21-day-long observation period with different manifestations and durations of the phases. Initial increase in the nociceptive sensitivity (hyperalgesia) was followed by an analgesic effect with subsequent return of the examined indices to the initial level. Low-intensity electromagnetic influences also induced modifications of the infradian rhythmics of th/p sensitivity of the molluscs; this was manifested in changes of the spectra and phase shifts of the identified rhythms and trends toward modulation of the amplitudes of these rhythmic components.