Related Experiment Video
Updated: Sep 23, 2026

Multi-Modal Signals for Analyzing Pain Responses to Thermal and Electrical Stimuli
Published on: April 5, 2019
Spatial heterogeneity not homogeneity of the magnetic field during exposures to complex frequency-modulated patterns
1Laurentian University, Sudbury, ON Canada.
Abstract:
24 young (4 mo.) and 24 old (8 mo.) male Wistar rats were exposed for 30 min. on two consecutive days to either a sham-field or to a frequency-modulated magnetic field applied through a pair of solenoids (spatially heterogeneous strength) or a Helmholtz coil (spatially homogeneous strength). The maximum field strength was about 2 microTesla. The rats exposed to the spatially heterogeneous magnetic field but not the homogeneous magnetic field exhibited strong analgesia to thermal stimuli applied to the footpads immediately after the treatment and 30 min. later. The effect accommodated 38% of the variance in the latency to respond to the thermal stimuli. These results suggest that the practice by many researchers in bioelectromagnetism to design coils to generate maximum spatial homogeneity of intensities within the exposure volume when applying complex weak magnetic fields may actually diminish any biological effects.
More Related Videos
07:52Simultaneous Recordings of Cortical Local Field Potentials and Electrocorticograms in Response to Nociceptive Laser Stimuli from Freely Moving Rats
Published on: January 7, 2019
08:05Electrophysiological Methods to Assess Peripheral Pain Block in an Anesthetized Rat
Published on: November 21, 2025
Related Concept Videos
Analgesia and Pain Management
Local Anesthetics: Differential Sensitivity of Nerve Fibers