FETUIN EXPRESSION IN THE DORSAL-ROOT GANGLIA AND TRIGEMINAL GANGLIA OF PERINATAL RATS

Fetuin, a fetal plasma glycoprotein, has been shown previously to be p resent in sub-populations of neurons in the developing central and per ipheral nervous system. To gain a more complete description of the tim e course of the appearance of fetuin during neurogenesis we have exami ned fetuin immuno-reactivity,and the presence of fetuin mRNA, in the d eveloping rat trigeminal and dorsal root ganglia. Fetuin immunoreactiv ity and its mRNA were first seen at embryonic day 15 in the trigeminal ganglia, and at embryonic day 16 in dorsal root ganglia. In both trig eminal and dorsal root ganglion, fetuin appeared to be present up unti l around the time of birth, and then again between postnatal days 3 an d 16. The results suggest that fetuin first appears at around the time that ganglion cell axons reach their central targets, which is also a pproximately when the cell-death period begins. The proportion of gang lion neurons that were fetuin immunoreactive at different ages was inv ersely related to the amount of cell death that is known to occur in t hese populations, thus it seems that fetuin is more likely to be assoc iated not with dying cells, but with those that survive the cell-death period. (C) 1997 ISDN.