Magnetic Pulses Elevate Nociceptive Thresholds: Comparisons with Opiate Receptor Compounds in Normal and Seizure-Induced Brain-Damaged Rats

Abstract

Normal rats or rats with seizure-induced limbic-thalamic damage were given one of five treatments: control, saline injections, morphine (4 mg/ kg) injections, naloxone (10 mg/kg) injections, or magnetic pulses, on 3 successive days. Flinch thresholds to electric shock were determined before the treatments and 20 and 40 min following the treatments on each of the 3 days. The results indicated that the magnetic pulsed fields (1 s of a 5 × 10 ⁶ T burst firing pattern every 4 s for 20 min) elicited a more prolonged and larger analgesic effect than the other treatments; the effect size was sufficient to be of potential clinical relevance. The characteristics of the magnetic treatment effect suggest there is a release of endogenous analgesics whose half-life is greater than experimental dosages of morphine.