Histological study on developing human olfactory bulb and olfactory tract

Present communication deals with histological study of human olfactory bulb. A light microscopy study revealed that the human fetal olfactory bulb is made up of six distinct concentric laminar layers. Starting from the surface, these are the Olfactory nerve fibre layer, glomerular layer, external plexiform layer, mitral cell layer, internal plexiform layer, and granular cell layer. Although visible in the prenatal stages of development, the layers of this laminar architecture were poorly formed at 15 GW. At 27 GW, all six layers were discernible in the olfactory bulb, but not all were present in the olfactory tract.