Variation in barbiturate sleeping time in mice. 3. Strain X environment interactions

Environmental factors such as diet, bedding material and temperature at the time of testing affected a 'model' pharmacological response--pentobarbitone sleeping time--differentially in a range of inbred strains. These results are probably explained by variations in the responses of the strains to constituents of the diets and bedding materials used in the experiments. Differences in the results between experiments suggest that there are also fluctuations in the composition of the diets and bedding materials over time. Strain X environment interactions such as those found here may explain differences in strain rankings between experiments. They would also account for some of the variability in results found between laboratories and within a laboratory over time.