MAGNETIC-FIELD CONDITIONED TASTE-AVERSION IN RATS

Conditioned taste aversion is a common classic conditioning procedure used to identify noxious stimuli. When a rat is given a taste solution , the conditioned stimulus (CS), followed by an unpleasant experience, the unconditioned stimulus (US), the rat will avoid consumption of th e CS in future presentations. These experiments use the taste aversion procedure to examine the effect of exposure to a high magnetic field. A solution consisting of 3.0 g glucose and 1.25 g saccharin per 1 L o f solution (G+S) was used as the CS and a 9.4-T magnet served as the U S. In Experiment 1, all rats received a 10 min presentation of the G+S solution followed by either a 30 min exposure to the magnetic field ( Magnet, n = 8), a 30-min exposure in a container with similar conditio ns but lacking the magnetic field (Sham, n = 8), or no exposure (Contr ol, n = 8). The Magnet Group showed a taste aversion on the first day of preference testing (p < 0.05). Experiment 2 employed the same US-CS protocol for 3 consecutive days of conditioning. The Magnet Group dem onstrated a taste aversion for the postexposure Days 1-8 (p < 0.01). T here was no difference between the Sham and Control Groups in either e xperiment. The results of this study clearly demonstrate that the rats associated the G+S solution with the experience of being exposed to t he high magnetic field and avoided the solution in subsequent presenta tions. (C) 1998 Elsevier Science Inc.