Fig. 2

Exogenous expression of zTrpa1b in sensory neuron of trpa1b?/? mutants and sub-cellular photo-activation. (a) Maximum intensity projection showing mosaic expression of zTrpa1b in Rohon-Beard neurons in the trunk of a zebrafish larva at 2.5 dpf. Red arrows and arrowheads indicate the Rohon-Beard neuronal cell body and its neurite projection, respectively. (b) Photomotor response was tested in trpa1b mutant (trpa1b?/?) controls, or in trpa1b mutants expressing zebrafish Trpa1b (zTrpa1b), zebrafish Trpa1a (zTrpa1a) or human TRPA1 (hTRPA1) in Rohon-Beard neurons (Video S1), pretreated with 10?µM optovin. Values are means?±?SEM from more than 3 experiments. Each experiment has n?>?10 per condition. *p?<?0.05. (c) Subcellular photo-activation of a zTrpa1b expressing Rohon-Beard neuron in a trpa1b mutant. MIP, confocal maximum intensity projection. Representative single plane time series images with photo-activation targeting neuron cell body (n?=?10) (left panel; Video S2) or neurite (n?=?9) (right panel; Video S3) in the trunk region of a zebrafish larvae in vivo. Red rectangular box indicates the time and location where photo-activation was made. (d) Current-Voltage relationships of zTrpa1b currents without treatment (black), 10 ?M Optovin alone (green), 10 ?M Optovin and light (magenta) and AITC (blue) (e) Peak whole cell zTrpa1b currents measured at ?100 mV (black trace) and +100?mV (red trace); Optovin-dependent photocurrents are highlighted in blue boxes, bounded by light switch-on (magenta bulb) and light switch-off (gray bulb). (f) Data from (e) with higher time resolution. (g) Box chart showing peak current densities of zTrpa1b in indicated conditions at ?100 mV and +100?mV (n?=?/>9, error bars represent SEM).