Fig. 6. Combined effects of BMI and CNQX. Representative data are from one animal (same animal as in Figs. 3b,c, 5b,c). a, Average effects on RF. BMI alone (median, 312 Hz above original RF; also see Fig.3a), CNQX alone (median, 296 Hz below original RF; also see Fig. 5a), and simultaneous injection of BMI and CNQX (median, 170 Hz below original RF) are shown. All data were collected during the same penetration and for the same injection site. The temporal sequence of antagonist injections (first BMI and then addition of CNQX or vice versa) made no significant difference on the postinjection RF. The statistical difference between the four groups was significant; p < 0.001. b, Effects on DSC. Injections of BMI alone (open triangles; also see Fig. 3c), CNQX alone (open squares; also see Fig. 5c), and BMI during ongoing CNQX injection (closed diamonds) are shown. Reversing the temporal sequence of antagonist applications, i.e., adding CNQX during ongoing BMI injection, eliminated the initial BMI effect (Fig. 3c) and resulted in similar blockage of DSC as shown here for CNQX and BMI (BMI +CNQX). For CNQX alone, n = 124 calls (4 cycles); for CNQX and BMI, n = 170 calls (4 cycles). c, Average compensation depth plotted relative to the bat's average median RF for CNQX alone (median, 938 Hz below original RF), BMI alone (median, 620 Hz above original RF), and BMI during ongoing CNQX injection (median, 4 Hz above original RF). The differences between all groups were statistically significant;p < 0.001.