Fig. 5

SLO-MO is necessary for location memory and changes future locomotion

(A) Two-photon laser ablation of selected functionally identified SLO-MO neurons in Tg(elavl3:GCaMP6f) fish.

(B) Ablating either population (example shown here: ablation of backward pre-displacement tuned cells) abolishes pre-displacement memory capacity of the entire population but leaves short-timescale sensory responses intact (C), suggesting integration through local connectivity within SLO-MO.

(C) Following ablation of one functional population (here, forward displacement tuned neurons), SLO-MO responses of the remaining population (here, backward-tuned neurons) remain visually responsive but lose their persistence. (Shaded regions: SEM in all panels.)

(D) Ablating neurons tuned positively to forward pre-displacement abolishes positional homeostasis in an example fish.

(E) Population data showing consistent abolishment of positional homeostasis across N = 6 fish after ablation of either the forward or the backward pre-displacement encoding population, but not for nearby control neurons. (One-sample t test, ^∗∗∗p < 0.001, p < 2.5e−5 for all pre-ablation, ^∗∗p < 0.01, p = 3.8e−3 for backward pre-displacements after control ablation, p = 6.4e−2 for forward pre-displacements after control ablation, n.s. p > 0.05. Error bars: SEM in all panels.).

(F) Stimulation setup for activating functionally identified SLO-MO populations using optogenetics in Tg(gad1b:Gal4; UAS:CoChR; elavl3:jRGECO1b) fish.

(G) Optogenetic activation of backward pre-displacement encoding neurons (green) causes increased swimming 5–10 s later, and activation of forward pre-displacement encoding neurons (magenta) causes decreased swimming. Control cells that do not encode location do not affect swimming. Inset: manually shifted trajectories to illustrate the similarity to behavior with visual pre-displacements.

(H) Population data showing consistent increases or decreases in swim distance following stimulation of neurons encoding backward or forward pre-displacements. (15 fish, one-sample t test, ^∗∗∗p < 0.001, p = 4.9e−4 for stimulation of backward-tuned SLO-MO cells, p = 2.1e−6 for stimulation of forward-tuned SLO-MO cells, n.s. p > 0.05, p = 0.15 for stimulation of control cells.).