The impact of newborn on adult mice: Open-field behavior along with pullus index

The open-field- (OF) dependent parameters ambulation, thigmotactical wall-seeking, radial latency, retrieving and pullus index were tested in both nulliparous and primiparous females as well as in unmated and mated males of the Swiss albino strain. The mice were housed under separate conditions and recorded in the absence as well as the presence of a biological or unrelated 1-day old pup placed either in the center or by the wall in a familiar OF. The results revealed an ambulatory response of recognition of the newborn’s genetic origin in single-caged females and family-housed males. The young’s initial OF location was decisive for adult OF behavior. In general, housing conditions affected family-caged primiparous females most. The pullus index or attraction toward pups reflected a need to retrieve the young. Simultaneous recordings of changes in two or more OF-dependent parameters made an integrate whole of the results.