STRAIN DIFFERENCE IN RESPONSE OF MICE TO d-AMPHETAMINE

¹ Biomedical Research Department, Research Center, Pitman-Moore Company, Division of The Dow Chemical Company, Indianapolis, Indiana

A qualitative difference in response of various strains of aggregated mice to d-amphetamine was observed. Swiss-Webster mice exhibited the usual 8-fold or so difference in lethality to amphetamine between the isolated and aggregated situation. C57BL/6 mice exhibited a significant difference but was less than 2-fold. Unexpectedly, BDF₁ and DBA/2 mice responded identically in the two situations. It was determined that the thresholds for pentylenetetrazol and for amphetamine were lowered for Swiss-Webster but not BDF₁ mice in the aggregate situation.

Quantitative differences between Swiss-Webster and BDF₁ mice were observed as determined by lethality determinations, anticonvulsant effects and alterations of hexobarbital sleep times. Such quantitative differences were not unexpected.

These results emphasize the need to specify in publications the strain of mice used in laboratory studies.