KINETICS OF CELL PROLIFERATION IN THE POSTNATAL RAT DENTATE GYRUS

Abstract

Cell cycle parameters in the dentate gyrus of the postnatal rat hippocampus were measured, using the method of percentage labeled mitoses. In animals aged 1, 6 and 12 days, cell cycle times range 15.1 to 17.7 h, S phase duration from 10.1 to 11.7 h, length of the G2 phase from 2.5 to 3.3 h and G1 from 1.1 to 2.4 h. These figures are similar to those obtained for other precursor cell populations in the brain. On the day after birth the labeling index in the dentate hilus is 4.5% and estimated turnover time 220 h, while on day 6 the labeling index is 3.7% and estimated turnover time 310 h. It is calculated that precursor cells outnumber granule cells by at least 3:1 at birth and 2:1 by day 6.