Figure 4

Direct physiological activation of mdIV neurons by UVC. (A) Representative single-unit extracellular recording traces from v’ada mdIV neurons in the larval body wall. Exposure to medium intensity UVC(M) increased the neuronal firing activity in wild-type neurons but ppk1 null mutant (DfA/DfB) mdIV neurons failed to respond. The UVC(M)-induced response was rescued by transgenic expression of wild-type PPK1 in mdIV neurons. (B) Spontaneous basal spike frequency in wild-type and ppk1 null mutant neurons. Spontaneous activity was restored by transgenic expression of wild-type PPK1 in mdIV neurons (n = 21, 13 and 8, respectively). ***p < 0.0001, one-way ANOVA with Tukey’s post comparison test vs wild-type. (C) Increase in mdIV neuronal firing rate in response to UVC(M) exposure represented a >4-fold increase from basal spontaneous firing frequency(n = 6 and 4, respectively). ***p < 0.001 from student t-test. All data are presented as mean±SEM.