Developing dentate nucleus in man: a qualitative and quantitative study.

Histological and quantitative studies were carried out in dentate nucleus (DN) of 14 human fetuses of gestational ages ranging from 10 weeks to 28 weeks in Nissl stained sections. The dentate nucleus was already well delineated at 11 weeks, but the adult profile was attained only by 27-28 weeks. The magnocellular dorsomedial region and the parvocellular ventrolateral region became apparent at 17-18 weeks. The numerical density of neurons showed a steady decline with advancing gestational age. However, the absolute neuronal count until 19-20 weeks was 367.1 x 10(3) followed by a count of 249.5 x 10(3) at 22-23 weeks. The reduction in the count between the two periods was significant and coincided with cell death which was striking between 19 and 23 weeks. The glial cell population continued to increase with advancing gestational age. The occurrence of significant neuronal cell death and its probable role in the developing human DN is reported for the first time.