Population data measuring the effect of neuromodulators applied in superior colliculus on spontaneous MUA and single-unit activity in superior colliculus. A, Effect of different doses of CA (in μm) on MUA spontaneous firing. *Statistical differences (Tukey, p < 0.05) between the groups. B, Effect of CA (0.5 mm) and NE (0.5 mm) or 5HT (0.5 mm) on single-unit spontaneous firing (NE and 5HTdata are pooled together). Note that to test the effect of NE or 5HT we selected cells with significant spontaneous firing during control. *Statistical differences (paired t test, p < 0.05) between the groups. C, Effect of fluoxetine (1.8 mm) and Physo (5 mm) on MUA spontaneous firing. *Statistical differences (Wilcoxon, p < 0.05) between the groups.