PRENATAL HUMAN LATERAL GENICULATE-NUCLEUS - A QUANTITATIVE LIGHT-MICROSCOPIC STUDY

Using morphometric methods, a quantitative study has been carried out on the lateral geniculate nucleus (LGN) of human fetuses ranging in ge stational age from 13 to 38 weeks. The volume of the nucleus as well a s the neuronal, glial and dead cell populations have been studied in N issl preparations. While the volume of the LGN shows a progressive inc rease throughout the period of study, the age period of 15-20 weeks is identified as a period of spurt in volumetric growth. Neuronal densit y and total neuronal number fall continuously while glial density and total glial population show a steady increase with advancing gestation al age. Pyknotic dead cells are seen throughout the period of study wi th a peak die off between 14 and 18 weeks. The study, for the first ti me, outlines the critical period for volumetric spurt and neuronal dea th in the developing human LGN.