An ethological analysis of the influence of perinatally-administered diazepam on murine behaviour.

A number of studies have found that the perinatal exposure of rodents to various tranquilizing agents alters their adult behaviour. Given the known anti-aggressive influence of acute doses of diazepam it was hypothesized that, when administered during pregnancy, this drug would change the adult social behaviour. The social interactions of adult male mice whose mothers were treated with diazepam or appropriate controls during pregnancy were video-taped and subjected to an ethological analysis that involved counting the incidences of 43 distinct postures. Prenatal but not postnatal diazepam treatment was associated with a large increase in the incidence of the sideways offensive posture. No significant differences resulted, however, in the case of other postures; in general exposure to prenatal diazepam produced few changes in adult social behaviour.