I2 and PHA neurons both respond to 1mM H₂O₂ in a <i>prdx-2</i>-dependent manner, but only PHA neurons respond to 10μM H₂O₂.

(A) Low-magnification DIC picture of L4 animals trapped in the microfluidic device used in all neuron recordings experiments. (B,C,F,G,J,K) Calcium response (visualized by GCaMP3) in I2R/I2L (B,F,J) and in PHAL/PHAR neurons (C,G,K) following H2O2 treatment (indicated by the red bar). Average curves show normalized neuron responses (time in seconds), in both left and right neurons (top and bottom curves). N, number of movies quantified for each genotype, in wild-type (B,C,J,K) and in prdx-2 mutants (F,G). (D,E,I) Bar graph showing the fraction of animals responding to the H2O2 stimulation in all experiments, classified as high (green), moderate (yellow) or absent (red) responses (see Methods). N, number of movies analyzed. (H,L) Quantification of the calcium response to H2O2 in I2 and PHA neurons in controls and in prdx-2 mutants at 1mM (H), and in I2L/R and PHAL/R controls, at 1mM and 10μM H2O2 (L). Bars represent the mean (N, number of movies) and error bars SD. ns, not significant, p>0.05; *pS1–S6 Movies and S5 Fig.