Morphological Maturation of the Olfactory Epithelia of Australian Marsupials

Abstract

In the early phase of independent mammalian life olfaction is reported to play an important part in nipple search, nesting behaviour and identification and bonding between mother and young (Hudson and Distel 1983; Schmidt et al. 1983; Grau 1976; Doty this Vol). Most of the studies of the functional development of the olfactory system have been carried out in rodents (Alberts 1976); the ontogeny of the pheripheral system has been studied in mice (Breipohl et al. 1973; Cuschieri and Bannister 1975) and the hamster (Waterman and Meiler 1973) and that of the olfactory bulb in the mouse (Hinds and Hinds 1976; Mair and Gesteland 1982; Benson et al. 1984). The general picture emerging from these studies is that the peripheral system which develops from the olfactory placode, reaches a developmental stage at birth capable of transmitting chemosensory information to the central system. However, central development of the olfactory circuits may be only partially complete at birth (Mair and Gesteland 1982; Greer et al. 1982) and may require input from the peripheral system in the early neonatal period for full development (Schmidt et al. 1983; Constanzo 1982). Postnatal importance of olfactory sensory experience may be different for marsupials for whom a short period in utero is characteristic and the young at birth differ in many respects from their eutherian counterparts, even in those mammals with a comparable gestation period. Moreover, their immediate postnatal conditions are very different.