MATURATION OF THE GFAP-IMMUNOPOSITIVE GLIAL NETWORK IS DELAYED IN THEOLFACTORY BULBS OF RATS SUBJECTED TO EARLY, LOW-DOSE X-IRRADIATION

Young rats were subjected to low-level, repeated doses of x-irradiatio n from a Co-60 source and examined for the presence and arrangement of their GFAP-immunopositive system at the light and electron microscopi c levels. In 2-week-old control rats, labelled cells were already dist ributed homogeneously throughout the bulb, while in the experimental a nimals, a (newborn- and early postnatal-type) radial arrangement of im munoreactive fibres continued to persist even until the end of the fou rth postnatal week. This delay in the maturation of the GFAP-immunopos itive glial system may contribute to the hindered development of the b ulbar neurones, neuronal connections, and field potentials, as found i n earlier studies. (C) 1994 Wiley-Liss, Inc.