Long term effects on activity in female mice following exposure to urine from lactating mothers

Infant female mice exposed to the urine of lactating donors prior to weaning subsequently showed, when adult, activity levels in keeping with those of the donors that provided the urine. Mice with low levels of activity provided urine which acted on target mice to restrict their movements and standing behaviour when tested in an open arena. The urine of high active donors enhanced activity as compared with the urine from donors of mid range activity levels. Housing in large groups reduced the activity of the recipients exposed to urine from the low active donors. The males were more active than the females but the exposure of males to the urine of the donors had no effect on their activity levels.