Figure 5. TRP channel blockers affect most of the L-arginine-induced responses.

A, L-arginine-induced Ca²⁺ responses of two ORNs of an individual slice of the lateral MOE (cyan and red trace). Incubation with 2-APB (100 µM; application for 5 min; orange-shaded panel) led to a strong reduction of the Ca²⁺ transient in one of the ORNs (red trace), whereas the second ORN was not affected (cyan trace). The response of the affected ORN recovered after 10 min of washout (right-hand traces). The bar diagram shows ORNs unaffected and affected by 2-APB (100 µM; 5 min), expressed as percentage of total ORNs tested (27 cells, 6 slices). B, mean Ca²⁺ transient (±SEM) of seven L-arginine-responsive ORNs of an acute slice preparation (lateral MOE; only blocker-affected ORNs included). With 2-APB in the bath solution (100 µM; 5 min; orange-shaded panel) the mean response is partially suppressed. After 10 min washout the response recovered almost completely (right-hand trace). The bar diagram shows that application of 2-APB (100 µM; 5 min) reduced the amplitude of the Ca²⁺ transients to 27% of the control application (24 ORNs, 6 slices). C, L-arginine-induced Ca²⁺ responses of two ORNs of another individual slice of the lateral MOE (cyan and red trace). Incubation with SKF-96365 (80 µM; 10 min; lilac-shaded panel) led to a strong reduction of the Ca²⁺ transient in only one of the two ORNs (red trace). The response of the affected ORN recovered after 10 min of washout (right-hand traces). ORNs unaffected and affected by SKF-96365, expressed as percentage of total ORNs tested (histogram; 25 cells, 4 slices). D, mean Ca²⁺ transient (±SEM) of four L-arginine-responsive ORNs of an acute slice preparation (lateral MOE; only blocker-affected ORNs included). With SKF-96365 in the bath solution (80 µM; 10 min; lilac-shaded panel) the mean response is partially suppressed. After 10 min washout the response slightly recovered (right-hand trace). Application of SKF-96365 (80 µM; 10 min) reduced the amplitude of the Ca²⁺ transients to 35% of the control application (bar diagram; 21 ORNs, 4 slices). Statistical analysis was performed using paired Student's t-test; *p<0.05, **p<0.01. [SKF, SKF-96365].