Impairment in behavioral sedation in rats during periods of elevated global geomagnetic activity.

The influence of the geomagnetic environment on the human organism and other biological entities has been a topic of intense scientific investigation. A large and growing body of evidence has linked elevated geomagnetic activity with effects on an array of neurological, immunological, cardiovascular, and psychological outcomes. For example, elevations in the rates of epileptic seizures, suicides, aggressive behavior, sleep disturbances, and sudden unexpected death from cardiac pathologies have been reported to occur more frequently on days associated with increased geomagnetic activity. Additional evidence also suggests that geomagnetic conditions might have an impact on the biological actions of specific drugs classes that have important implications for pain management, sedation, and seizure control. The present study set out to determine if periods of enhanced geomagnetic activity could influence the induction of behavioral sedation by pentobarbital in rodents undergoing a routine surgical procedure. The surgical records of 250 subjects were retrospectively analyzed, and the occurrence of complete behavioral sedation (e.g., loss of righting reflex, lack of nociceptive response to tail pinch, absence of corneal and conjunctive reflexes) was noted. We found a significant correlation between periods of increased geomagnetic activity and the number of non-responsive surgical patients (i.e., patients still demonstrating behavioral responsiveness after treatment with pentobarbital). These findings provide evidence for the first time that the potential efficacy of some surgical anesthetic compounds might be reduced on days associated with increased geomagnetic activity. Potential mechanisms are presented, and the broad implications of these findings to phenomena such as surgical awareness are discussed.