Fig. 5: DVC initiates backward locomotion by activating AVA.
From: Hierarchical competing inhibition circuits govern motor stability in C. elegans
a Schematic showing major interneurons downstream of DVC. “n” indicates the chemical synapse number (adapted from Wormweb.org). b Schematic diagram of the locomotion response to optical activation of DVC. c Average velocity and quantified backward duration in response to light stimulation in different genotypes (n = 15 animals per group) (p < 0.001). DVC initiated robust backward locomotion. Error bars, SEM. d, e Blocking the chemical synapses of DVC (d) (n = 14 (-TeTx) or 15 (+TeTx) animals) (p < 0.001) and ablation of AVA (e) (p < 0.001) (n = 15 animals per group) disrupted the DVC-evoked backward locomotion. Error bars, SEM. f-i Upper, Schematic diagram of the in situ electrophysiological configurations. By activating DVC, neural network activity was recorded in BWMs. Representative postsynaptic PSCs traces (f i) and APs’ diagrams (g i) from different conditions. Lower, quantification of the altered average current (f ii, iii) and AP frequency (g ii, iii) after light illumination (For V clamp, n = 9 (-ATR), 12 ( + ATR), 19 (+TeTx, +ATR) animals in (f), and n = 11 (AVA + ), 18 (AVA-) animals in (h). For I clamp, n = 8 (-ATR), 10 ( + ATR), 9 (+TeTx, +ATR) animals in (g), and n = 8 (AVA + ), 8 (AVA-) animals in (i)) (f ii: p = 0.1206, <0.001, = 0.7062, f iii: p = 0.5139, <0.001, g ii: p = 0.2012, 0.0015, 0.4865, g iii: p = 0.8815, <0.001, h ii: P < 0.001, = 0.2579, h iii: p < 0.001, i ii: p < 0.001, = 0.4463, i iii: p < 0.001). j, k Upper, Schematic diagram of the in situ electrophysiological configurations. By activating DVC, synaptic activity was recorded from AVA neurons. Lower, Representative postsynaptic PSC traces (j i) and membrane potential traces (k i) and the quantified Δ Average current (j ii, iii) and Δ Voltage (k ii, iii) are shown (For V clamp, n = 6 ( + ATR), or 5 (-ATR) animals. For I clamp, n = 7 ( + ATR), or 7 (-ATR) animals) (j ii: p = 0.0355, 0.9144, j iii: p = 0.0299, k ii: p < 0.001, = 0.7497, k iii: p < 0.001). The above p-values are all listed in the order of significance symbols (from top to bottom, left to right). Δ, difference between illumination and preillumination. AP freq., action potential frequency. Yellow shaded, light stimulation. Yellow arrows, light stimulation. *p < 0.05; ***p < 0.001; ns, not significant by two-tailed Student’s t test (comparison between the two groups) or one-way ANOVA (comparison among the three groups). Error bars, SEM. Source data are provided as a Source Data file.
