fig3

Figure 3. Silver gold staining of brain tissue showing morphological variation of microglia/macrophage in both developing and adult rat brain (×100, Oil immersion). (A) In late embryo, densely stained myelo-monocytic lineage cells (indicated by red arrows) along with other neuroglial cells and a distinct neuronal cell body are observed in brain tissue matrix. "N" represents nucleus of the neuron; (B) in neonates, mostly amoeboid microglial cells (indicated by red arrows) are evenly distributed throughout the matrix and a distinct ramified microglia (indicated by yellow arrow) is also appeared; (C) whereas in young adult, ramified microglia with their slender ramifications (indicated by yellow arrow) are clearly visible and cells with amoeboid morphology (indicated by red arrow) are also observed. In addition, the entry of a deeply stained cell into the brain matrix from a capillary (indicated by violet arrow) is visible; (D) in late adult, both irregular shaped amoeboid microglia (indicated by blue arrow) and ramified microglia with their projections (indicated by yellow arrow) are clearly found in cortical regions. From blood capillary or vasculature the entry of myeloid cells in brain parenchyma is visible by the presence of deeply stained cells at the margin of capillary (indicated by violet arrow), among them a few cells just entering into the tissue matrix and resides there