The effects of benzodiazepines on the behaviour of mice on a hole-board

The effect of exposing mice to a hole-board in reducing the number of head dips made on a subsequent exposure was studied. The period of first exposure that was effective in causing this reduction, the interval between exposure that must elapse before this effect appears and the duration of the effect were also determined. Chlordiazepoxide and other benzodiazepine tranquillizers, given before initial exposure, increased activity in small doses but had little effect upon subsequent activity. They did not affect characteristics of familiarization beyond possibly a slight shortening of the latent period.