EFFECT OF SINGLE EXPOSURE TO TOLUENE ON SIDMAN AVOIDANCE RESPONSE IN RATS

Abstract

Effects of single exposure to toluene on Sidman avoidance response in rats were studied. The animals, in which the behavioral base line had been established, were exposed 0, 1, 000 and 3, 000ppm of toluene vapor for 4 hours and the effects on the behavioral pattern were investigated using Sidman avoidance test for one hour after the termination of toluene exposure. 1) Exposure to 0 or 1, 000 ppm of toluene did not produce marked change on the operant behavior. After the exposure to 3, 000 ppm, the animals produced increased responses with shortening of the inter-response-time (IRT) and no changes in shock counts from the beginning to the 50min. zone of the Sidman avoidance test when compared with those before exposure. The behavioral change indicated here appears to be caused by a temporary breakdown of the established timing of lever pressing. 2) The effect of toluene on the operant behavior was strongest immediately after the termination of the exposure and the behavior recovered in about an hour. This result suggested that toluene is rapidly transfered to and removed from the brain.