RO 15-1788 does not influence postpartum aggression in lactating female rats.

Recently, Hansen et al. (1985) suggested behavioural similarities between lactating rats and non-maternal rats treated with benzodiazepines (BDZ), indicating that lactation may be associated with an increased activity state at the GABA/BDZ receptor complex similar to BDZ treatment. A logical prediction of this hypothesis is that BDZ antagonists should decrease typical maternal behaviours involved, such as aggression. We tested this hypothesis by measuring the behavioural effects of the BDZ antagonist RO 15-1788 (1.25-10 mg/kg IP) on aggressive behaviour of lactating female rats confronted with male intruders. We could not support the hypothesis; no consistent behavioural effects of RO 15-1788 on aggression were found. The implications of this finding for the proposed hypothesis are discussed.