Fig. 2

Attenuation of fictive synaptic depolarizations to spinal primary motoneurons during touch-evoked locomotor activity in larvae expressing mutTARDBP. (A) From left to right: a bright field image of a 54 hpf zebrafish trunk in a transgenic larvae expressing GFP (magenta) under the control of the motoneuron specific promotor Hb9, with a patch electrode dialyzing a CaP motoneuron with sulforhodamine (cyan). Fictive motor patterns were elicited with a light puff of water onto the tail using a picospritzer. (B) Example traces of CaP motoneuron synaptic depolarizations following light touch. Note the presence of increased spontaneous EPSPs following touch-evoked motor-related depolarizations (insets). (C) No differences were found in the delay between the touch and start of depolarizations among wild type larvae, larvae expressing wtTARDBP or larvae expressing mutTARDBP. However, both the duration of synaptic depolarizations (D) and the number of APs (E) elicited following light touch in larvae expressing mutTARDBP were found to be reduced when compared to either wild type larvae or larvae expressing wtTARDBP. Though fewer APs were generated in larvae expressing mutTARDBP, the frequency of APs (F) was not found to be different from wild type larvae or wtTARDBP larvae. Numbers in parentheses represent sample sizes. Asterisks and daggers represent statistical differences from wild type (p < 0.05) and wtTARDBP (p < 0.05) larvae respectively.