A) Sample trace of control larvae without retinal in which RIS cannot be activated optogenetically. RIS speed was measured. B) Long-term optogenetic RIS activation by orange light in the presence of retinal. C) Long-term activation of RIS by ReaChR leads to an initial strong increase in calcium activity in RIS and simultaneous mobility quiescence followed by a mild RIS activity increase yet no increase in movement speed or movement quiescence. D) Comparison of RIS activity level changes caused by RIS::unc-58gf(strong) and by optogenetic activation of RIS. The data was normalized to their respective controls. E) Long-term optogenetic activation of RIS significantly increases RIS baseline. *p<0.05 Welch test. F) Transients in RIS are significantly reduced in magnitude and don’t correlate with quiescence. **p<0.01 Welch test. G) Long-term optogenetic activation of RIS inside microfluidic chambers leads to a small increase in survival (p = 0.09 Logrank test, p = 0.02 Fisher’s Exact Test, the average of all individual worms of all three technical replicates was averaged, n = 92 for RIS::ReaChR(+ATR), n = 98 RIS::ReaChR(-ATR), n = 124 wild type (+ATR), n = 108 wild type (-ATR)).