Maternal behavior in normal and androgenized female rats: effect of age and experience

The aim of the experiments presented here was to evaluate the influence of age and of previous maternal experience on care of pups in normal virgin and androgenized Wistar female rats. When sensitization occurred before they were 60 days old, androgenized females failed to develop consistent retrieving, probably because of excessive timidity (Experiments 1 and 2) whereas they were able to keep pups warm in their nests. During pup-toy choice tests (Experiment 2) young androgenized females displayed only erratic carrying of toys. On the other hand, 60-, 80- or 100-day-old androgenized females developed full maternal behavior like cyclic controls. In the third experiment, control and androgenized females exposed to pups when 60 days old, were reexposed when 95 days old. Androgenized females proved to be more sensitive to earlier exposure to pups than control females and showed significant reductions in latencies of emergence of maternal responses.