Conditioned taste aversion is a classic conditioning procedure used to identify noxious stimuli. When a rat is given a taste solution (the conditioned stimulus) followed by an unpleasant experience (the unconditioned stimulus), the rat will avoid consumption of the conditioned stimulus in future presentations.
A solution consisting of glucose and saccharin was used as the conditioned stimulus and a 9.4-T magnet served as the unconditioned stimulus. In Experiment 1, all animals received a 10 min presentation of the glucose + saccharin solution followed by either a 30 min exposure to the magnetic field. Experiment 2 employed the same unconditioned stimulus-conditioned stimulus protocol for 3 consecutive days of conditioning.
|Chamber||plexiglass tube (5cm diameter) to restrain rats|
|Setup||The plexiglass tube containing the rat was inserted into the magnet|
|Additional info||The tube had a cone shape in which the head of the animal was inserted. The core had a 1 mm hole for breathing purpose. A plug which accommodated the tail was inserted into the bottom of the tube to restrain movement. The control rats remained in their home cages|
In the first experiment the exposed magnet group showed a taste aversion on the first day of preference testing.
In the second experiment the magnet group showed a taste aversion for the post-exposure days 1-8. There was no difference between the sham exposure and control groups in either experiment.
The data clearly revealed that the animals associated the glucose + saccharin solution with the experience of being exposed to the high magnetic field and avoided the solution in subsequent presentations.