Figure 4. Diacylglycerol but not phosphatidylinositol-3-phosphate or arachidonic acid is involved in amino acid-signaling in the lateral MOE.

A, L-arginine-induced Ca²⁺ responses of two ORNs of an individual slice of the lateral MOE (cyan and blue trace). Incubation with Xestospongin C (500 nM; application for 10 min; green-shaded panel) did not affect the responses. B, mean Ca²⁺ transients (±SEM) of all three L-arginine-responsive ORNs of an acute slice preparation (lateral MOE). The responses were not affected by Xestospongin C (500 nM; 10 min; green-shaded panel). C, L-arginine-induced Ca²⁺ responses of two ORNs of an individual slice of the lateral MOE (red and purple trace). Application of SAG (200 µM; 10 s, middle panel; 50 s, right-hand-panel) triggered Ca²⁺ increases in both ORNs. D, L-arginine-induced Ca²⁺ responses of two ORNs of an individual slice of the lateral MOE (black and grey trace). Both ORNs did not respond upon application of AA (50 µM; 10 s, middle panel; 60 s, right-hand-panel) E, mean responses (±SEM), expressed as percentage of control response to L-arginine, of 14 ORNs (4 slices) in standard (dark grey columns) and bath solution with Xestospongin C 500 nM (green columns; respectively 5, 10 and 15 min after application of Xestospongin C; washout time was 5 min). No significant reduction of the Ca²⁺ responses was observed (p>0.05; paired Student's t-test). F, mean response amplitudes (±SEM) upon application of L-arginine (dark grey columns) and SAG (purple columns; 200 and 500 µM; 7 ORNs, 2 slices and 9 ORNs, 2 slices, respectively). The response amplitudes to SAG were lower but not significanty different from the L-arginine responses (p>0.05; paired Student's t-test). [AA, arachidonic acid].