Rosamund J. Wealthall

Macrophages and dendritic cells in the rat meninges and choroid plexus: three-dimensional localisation by environmental scanning electron microscopy and confocal microscopy

The present investigation provides novel information on the topographical distribution of macrophages and dendritic cells (DCs) in normal meninges and choroid plexus of the rat central nervous system (CNS). Whole-mounts of meninges and choroid plexus of Lewis rats were incubated with various anti-leucocyte monoclonal antibodies and either visualised with gold-conjugated secondary antibody followed by silver enhancement and subsequent examination by environmental scanning electron microscopy or by the use of fluorochromes and confocal microscopy. Large numbers of MHC class II+ putative DCs were identified on the internal or subarachnoid aspect of dural whole-mounts, on the surface of the cortex (pia/arachnoid) and on the surface of the choroid plexus. Occupation of these sites would allow DCs access to cerebrospinal fluid (CSF) and therefore allow antigens into the subarachnoid space and ventricles. By contrast, macrophages were less evident at sites exposed to CSF and were more frequently located within the connective tissue of the dura/arachnoid and choroid plexus stroma and also in a sub-pial location. The present data suggest that DC may be strategically located within the CNS to sample CSF-borne antigens. Furthermore, the data suggest that CNS tissue samples collected without careful removal of the meninges may inadvertantly be contaminated by DCs and meningeal macrophages.

Surface Remodelling of the Facial Skeleton in Juvenile Macaca mulatta: Implications for Sexual Dimorphism

Facial growth in primates has been investigated in the context of the growth processes occurring on the bone surface, known as surface remodelling, and such remodelling patterns have helped explain interspecific differences in adult shape [1, 2]. The development of sexual dimorphism, however, has yet to be investigated in the context of remodelling, as previous studies have used juveniles of unknown sex [1, 3, 4]. If Macaca mulatta males and females are scaled ontogenetically [5], no difference in surface-remodelling patterns between the sexes might be expected. Thus, the aim in the present study is to investigate surface remodelling of the facial bones in a mixed-sex growth series of M. mulatta.