Developmental Changes in Expression of a Calcium-binding Protein (Spot 35-calbindin) in the Nervus Terminalis and the Vomeronasal and Olfactory Receptor Cells

Abstract

The detailed localization of spot 35-calbidin and its ontogenic change were studied in Nervus terminalis, the vomeronasal organ and the olfactory epithelium of the rat by immunohisto-chemistry. At the embryonic days 12 and 13 (E 12-13), calbindin-immunoreactive cells were found in the outermost layer of the presumptive olfactory bulb and within the olfactory placode. At E 14 to the postnatal day 1 (P 1), intense calbindin-immunoreactivity was localized in ganglionated fiber bundles of Nervus terminalis coursing through the mesenchymal spaces on both sides of the nasal septum. Nervus terminalis decreased the immunoreac-tivity abruptly after P 1 and it showed no distinct immunoreactivity for calbindin at P 7 and thereafter. On the other hand, numerous receptor cells in the olfactory epithelium and the thicker vomeronasal epithelium exhibited weak to moderate immunoreactivity for calbindin at E 18-P 1. Their immunoreactivity decreased in intensity progressively after P 7 and no distinct immunoreactivity for calbindin was detected in most of the receptor cells, whereas moderate immunoreactivity was detected in most of the vomeronasal and olfactory nerves at P 28 and P 63.

Key Words:

• immunohistochemistry
• calbindin
• Nervus terminalis
• vomeronasal organ
• olfactory epithelium
• development