Plate 3: Representative Micrographs of Spleen. (A, B) Control rat tissue with normal red (R) and white (W) pulp. Secondary lymphatic follicle (F) with pale staining germinal center (g) and small central artery (a) are also seen. A marginal zone (arrow) is clearly differentiated from the red pulp. Many blood cells (bc) are also noticed in the red pulp (C, D) MSG-treated rat tissue showing small sized lymphatic follicles with no germinal centers and large congested blood vessel (v). Differentiation between red and white pulp is indistinct. Many lymphocytes (arrow) with different sizes and darkly stained nuclei are seen in the white pulp and blood cells. Splenic sinusoids (s) are scattered in the red pulp. (E, F) Recovery group rat tissue shows lymphatic follicles of different sizes with absence of germinal centers. Many aggregations of darkly stained lymphocytes (white arrow) and eccentric artery (a) are seen within the follicles.A marginal zone (arrow) is differentiated from the red pulp. Many blood cells are present within dilated blood sinusoids. H&E stain. (Images scale bar,A,C,E; 100 μm & B, D, F; 25 μm).