A comparison of the effect of mescaline on activity and emotional defaecation in seven strains of mice.

1 Mescaline hemi-sulphate (35 mg/kg body weight) was injected intraperitoneally into male mice (Mus musculus) from seven genetically diverse laboratory strains. 2 The effect of mescaline was found by comparison of the emotional defaecation and open field activity of mice after mescaline injection with the performance of the same mice after a subsequent saline (0.9% w/v NaCl solution) control injection. 3 In strains A2G, C3H/He, C57BR/cd, CBA/Cam and F/St, mescaline inhibited emotional defaecation and stimulated open field activity. These effects did not occur in strains 1CFW and Schneider. 4 A positive relationship was found between the degree of emotional defaecation characteristic of each strain in the saline control experiment and the inhibitory effect of mescaline on emotional defaecation. 5 Pre-treatment of mice with tranylcypromine (20 mg/kg body weight, i.p.) had no effect on emotional defaecation or on its inhibition by mescaline.