Figure 6.

Receptors involved in microglial process retraction. A, The stable adenosine analog 2-chloro-adenosine (100 μm) induced a small reduction in mean microglial cross-sectional area (4 MTLE and 2 PTC ramified cells). B, The A2A receptor antagonist Preladenant (5 μm) did not suppress process retraction induced by 2 mm ADP (mean, normalized data from n = 4 ramified PTC cells). C, The nonhydrolyzable ATP analog 2MeSATP (100 μm) reduced the mean cross-sectional area of 3 ramified microglia of MTLE tissue. D, P2Y1 receptor antagonists MRS2500 or MRS2179 (10 μm) did not prevent the reduction of microglial cross-sectional area induced by 2 mm ADP in ramified microglia (4 MTLE, 2 PTC cells). E, The P2Y13 antagonist MRS2211 (30 μm) did not suppress process retraction induced by 2 mm ADP in 4 ramified PTC microglia. F, Coapplication of MRS2500 (10 μm) and MRS2211 (30 μm) suppressed retraction induced by 2 mm ADP (5 ramified cells: 2 MTLE, 3 PTC cells). G, Response of an initially ramified microglia (PTC) to 2 mm ADP in the presence of MRS2500 (10 μm) and MRS2211 (30 μm). From left, CTRL, basal state, in the presence of both antagonists, and then 2 mm ADP. Merge image represents the difference between cell shape in the presence of both antagonists and then after applying ADP. Red represents new fluorescent signal; green represents lost signal; yellow represents maintained signal. Movie 5 shows that the coapplication of P2Y1 and P2Y13 receptor antagonists suppresses process retraction.