CASES OF SPRAGUE-DAWLEY RATS WHICH DID NOT RESPOND TO AN ALARM SUBSTANCE IN THE FORCED SWIMMING TEST

The fact found by Abel and his group that rats produce an 'alarm subst ance' while swimming was examined by employing a single-subject approa ch. Sprague-Dawley rats were rested in the forced swimming test situat ion in fresh water and in mater soiled by another rat. In Exp. 1, Spra gue-Dawley rats from Japan SLC, Inc. were used. No evidence of respond ing to the 'alarm substance' was found. Then, further experiments were conducted employing methods similar to those of Abel and his group. I n Exp. 2, Sprague-Dawley rats from Charles River, Japan, were used. In Exp. 3, the water depth and inner diameter in a cylinder used were th e same as those used by Abel and his group, and the mater was soiled m ore thoroughly. In Exp. 4, the level of water contamination was raised to four times that employed in Exps. 1 and 2. However, the series of experiments yielded no evidence of the 'alarm substance.' Breeder diff erences among subjects might explain the discrepancy in results.