Kw. Kafitz et Ca. Greer, DIFFERENTIAL EXPRESSION OF EXTRACELLULAR-MATRIX AND CELL-ADHESION MOLECULES IN THE OLFACTORY NERVE AND GLOMERULAR LAYERS OF ADULT RATS, Journal of neurobiology, 34(3), 1998, pp. 271-282
Owing to the continual turnover of afferent input, the olfactory syste
m offers a unique opportunity to study development and reorganization
of neuronal networks in adults, To explore substrates that may underli
e these processes in the adult olfactory system, we examined the expre
ssion and distribution of extracellular matrix and cell adhesion molec
ules (CAM) thought to be involved in axon guidance/extension. NCAM, la
minin, and tenascin were all detected by immunocytochemistry in the ne
rve and glomerular layers of the adult rat olfactory bulb, although th
e intensity and laminar distribution were varied, Antisera for N-CAM(t
otal), N-CAM(180), and tenascin bound to fascicles within the olfactor
y nerve layer and the glomerular neuropil, However, binding was nonuni
form in that only subsets of axon fascicles and restricted glomeruli s
howed evidence of immunoreactivity, Antilaminin and a polyclonal antit
enascin similarly exhibited heterogeneous intralaminar immunoreactivit
y, Tenascin colocalized with glial processes at the borders of glomeru
li and subcompartments of the glomerular neuropil, Laminin immuno-reac
tivity was evident in subsets of olfactory nerve fascicles and, to a l
esser extent, the glomeruli. The data are consistent,vith the notion t
hat ongoing axon extension and glomerular targeting in the olfactory s
ystem is subserved in part by a heterogeneous expression of the same e
xtracellular matrix and CAMs present at higher levels during perinatal
development, (C) 1998 John Wiley & Sons, Inc.