LOCALIZATION OF THE THY-1 ANTIGEN IN THE CEREBELLAR CORTEX OF RAT-BRAIN BY IMMUNOFLUORESCENCE DURING POSTNATAL-DEVELOPMENT

Abstract— At birth in the rat brain the Thy‐1 antigen was present at 10% of the adult level and increased rapidly to reach near adult levels after 3 weeks. Localization studies by immunofluorescence on sections of rat cerebellar cortex during this period showed that at day 5 there was weak fluorescence associated mainly with the molecular layer and some fibre‐like structures in the centre of the folium; no fluorescence was found around the cells of external granular layer. From 5 to 16 days there was a rapid increase in Thy‐1 immunofluorescence with noticeably higher levels associated with the white matter than the molecular layer. However, by 21 days the reverse was found’ with lower levels in white matter than in the molecular layer with a similar distribution to that observed previously in adult rat cerebellum. Small rings and patches of fluorescence were observed in the molecular and granular layers. The results indicated that Thy‐1 was present on axons, mature neurons and their processes. In addition, Thy‐1 immunofluorescence was found in the pia‐arachnoid until around day 16. Copyright © 1979, Wiley Blackwell. All rights reserved