Effects of bromide on behaviour of mice

Groups of mice, housed individually in standard cages placed in a frame especially designed for the recording of locomotive behaviour, were fed diets containing sodium bromide at a level of 0, 400, 1200, 3600 or 10,800 ppm for 36 days. A fully automated system was used to record and process measurements of the nocturnal motility of the mice, together with three other variables (evasion time, spontaneous treadmill performance and body weight), for a total of 128 days before, during and after administration of the test diets. The data obtained, analysed statistically by univariate and multivariate analysis of variance, indicated that for sodium bromide, the 'effect limit' based on behavioural variables and body weight lay for mice between 400 and 1200 ppm in the diet. The fact that the overall effect of the 10,800 ppm dietary level was not completely reversible seemed to be largely attributable to the effect of this level of sodium bromide administration on body weight.