Effects of Central Depressants on Rota-Rod and Traction Performances in Mice

Abstract

The effects of the central depressants, chlorpromazine, diazepam, pentobarbital and ethanol, on rota-rod and traction performances in mice were investigated. The walking technique of the animals on the rotating rod (3 cm in diameter, 24 rpm) was established after about 15 trials and was well maintained for 1 wk thereafter. No training was required for traction. The rota-rod and traction performances were inhibited by chlorpromazine, diazepam, pentobarbital and ethanol in fairly good parallel with the dosages. The sensitivities to 1 same drug markedly differed between the 2 performances. Chlorpromazine more than diazepam inhibited the rota-rod, while in the traction performance the inhibition with diazepam was greater than that with chlorpromazine. Pentobarbital and ethanol inhibited the 2 performances to nearly the same degree. The rota-rod test is apparently suitable for estimation of the positive adaptability to forced motor activity and the traction for that of muscle relaxation. By comparing dose-effect relationships in the 2 performances, it may be possible to elucidate characteristics of various central depressants and to apply these procedures for the screening test in drug evaluations.