Developmental changes in open-field behavior in the kitten

Seventy-eight kittens from 3 to 7 weeks of age were studied in an open-field arena. Three major age-dependent changes were noted: (1) the number of floor squares entered was markedly higher for 5- and 6-week-olds than for younger animals, and slightly lower for 7-week-olds than for 5- and 6-week-olds; (2) the tendency to backtrack from 1 square to a just-vacated square decreased with age, the largest change occurring between 4 and 5 weeks of age; (3) the within-session decrement in locomotion was largest for 3-week-old kittens but was smallest for 4-week-olds and increased monotonically with age thereafter. The results suggest a possible role of hippocampal maturation.