Radial arm maze performance of rats following repeated low level microwave radiation exposure

Abstract

We examined the possibility of changes in "working" memory of rats following whole body exposure to microwave (MW) radiation. During each of 10 days, we exposed rats within circularly polarized waveguides for 45 min to 2450 MHz fields at whole body SARs of 0.6 W/kg (2 micros pulses, 500 pps), followed by testing in a 12 arm, radial arm maze (RAM). Rats received a preexposure injection of one of three psychoactive compounds or saline, to determine whether a compound would interact with MW exposure to affect performance in the maze. Error rate, i.e., reentry into arms already visited, and time to criterion data for 10 consecutive days of testing were analyzed by a three way analysis of variance (ANOVA) using main effects of "exposure" and "drug" and a repeated factor of "test day." Our alpha limit for significance was P <.05. Analyzes of error rates revealed no significant exposure effect, no significant drug effect and no significant interaction between the two main factors. There was a significant difference in test days, as expected, with repeated test-trial days, which indicates that learning was accomplished. There was no significant interaction of test day and the other two factors. The results of our analyzes of time to criterion data included no significant exposure effect, a significant drug effect, a significant test day effect, and a significant interaction between drug and test day factors. Post hoc analyzes of the drug factor revealed that rats treated with either physostigmine or nalrexone hydrochloride, took significantly longer to complete the maze task than rats pretreated with saline or with naloxone methodide. We conclude that there is no evidence from the current study that exposure to of MW radiation under parameters examined caused decrements in the ability of rats to learn the spatial memory task.

Cognitive impairment in rats after long‐term exposure to GSM‐900 mobile phone radiation

“…Alterations in opioid neurotransmitter properties were suggested as a plausible explanation. However, these findings could not be replicated by Cassel et al [2004] or Cobb et al [2004].…”

Neurobehavioural effects of electromagnetic fields

“…Similarly, Dubreuil et al [2002Dubreuil et al [ , 2003 found no effects on the performance of rats on several maze tasks (as well as an object recognition task) following exposure to pulsed 900 MHz fields using a head-only system. Finally, two recent attempts to replicate the radial arm maze experiment of Lai et al [1994] did not find any field-dependent effects [Cassel et al, 2004;Cobb et al, 2004]; such exposures were also shown not to affect anxiety levels as assessed using an elevated plus maze [Cosquer et al, 2005]. In addition, unpublished experiments from the authors' laboratory have found that exposure of mice to fields representing GSM, UMTS or TETRA signals have no significant effects on place learning and spatial memory.…”

Effect of electromagnetic radiations on brooding, honey production and foraging behavior of European honeybees (Apis mellifera L.)

“…Average EMR frequency on Apis mellifera colonies during the observation period. recent studies have also demonstrated that various tissues, cellular activities, memory, and learning in humans, rats, and mice are not affected when subjected to GSM or GSM-like microwave radiation (Cobb et al, 2004;Dasdag et al, 2003Dasdag et al, , 2004Dasdag et al, , 2008Dubreuil et al, 2002Dubreuil et al, , 2003Forgacs et al, 2006;Joubert et al, 2007;Kumlin et al, 2007;Sienkiewicz et al, 2000;Smith et al, 2007;Thorlin et al, 2006;Tillmann et al, 2007). Nevertheless, these findings should not downplay the potential health hazards involved with the use of cellular phones.…”