Alcian blue-positive GRID cells are localized within the connective tissues of differentiated tissues in the limb.
(a) GRID cells within the connective tissue of the dermis of the skin (M, skeletal muscle; DG, dermal skin gland; asterisk, dense collagen layer of the dermis). (b) Network of GRID cells surround a nerve. (c) Grid cells interspersed within skeletal muscles. (d) GRID cells within the loose connective tissue of the dermis surround blood vessels (M, skeletal muscle; asterisk, dense collagen layer of the dermis; arrowheads, nucleated erythrocytes within blood vessels). Scale bars: 50 μm.