LHR immunostaining in the gray matter of the human brain parietal lobe. A) LHR+ microglial cells with characteristic dendritic processes (full arrowhead) and flattened nuclei (yellow arrowheads). Green arrowhead indicates unstained nerve cell. B) Area occupied by microglia (full and yellow arrowheads) contains unstained nerve cells (green arrowheads). However, area lacking microglia contains LHR+ nerve cells (red arrowheads). C) Staining for leukocyte common antigen (LCA) reveals picture similar to that in (A). Note dendritic processes of microglial cells (full arrowheads), and interaction with neuronal (red arrowhead) and other glial elements (white arrowhead). D) Anti human Thy-1 (hThy-1) shows diffuse staining of brain tissue except for the vascular endothelium (v). E) Control staining with anti-rat Thy-1 (rThy-1). F–K) Schematic drawings of interstitial (glial) cells in the human brain and differences in their nuclei (from Ref. ). F) Fibrous astrocytes – white matter. G) Oligodendroglial cells – satellites to nerve cells. H) Protoplasmic astrocytes – grey matter. I) Microglial cells – mesodermal origin, gray and white matter. Yellow arrowhead indicates flattened nucleus of microglial cell. J) Irregularly oval nuclei of astrocytes (full arrowhead) and oval nuclei of oligodendroglia (white arrowhead). K) Small, often flattened nuclei of microglial cells. L) CD68 staining shows flattened nucleus of microglial cell (yellow arrowhead). M) No staining was observed with CD14, a marker of monocytes and immature tissue macrophages. Hematoxylin counterstain: weak in panels A and B, moderate in C-E, L and M. Bar in M, for A-E, L and M.