Figure 8.

The duration of the stance controls the hyperpolarization in HS cells at multiple timescales

(A) Left, schematic of the experimental configuration. Right, the relation between Vf and stance duration during head-fixed walking on the ball. Orange/blue: short/long stances (n = 19 fly cell pairs; lines connect the same individual). The fly walks faster with shorter stances (p = 0.000163, Z = 3.82, the signed-rank test).

(B) ΔVm (grand mean ± SEM, n = 19 fly cell pairs) as a function of the stride cycle for shorter (orange) and longer (blue) stances.

(C) Same as (B), but for 10 consecutive strides (n = 17 fly cell pairs).

(D) The difference between Vm at the beginning versus the end (“offset,” dashed lines in B and C) of a single (left) or ten consecutive strides (middle). p = 0.00054, Z = −3.46, n = 19 fly cell pairs for a single stride; p = 0.00060, Z = −3.43, n = 17 fly cell pairs for ten strides. Right, the offset in Vm was compared between the end of stride 1 and 10. P = 0.019, Z = −2.34, n = 17 fly cell pairs, the signed-rank test.

(E) Same as (B) but for 5-40^Leg > TNT (n = 8 fly cell pairs) and control (n = 6 fly cell pairs) flies.

(F) The hyperpolarization of HS cells during stance as a function of stance duration (5-40^Leg > TNT, red, n = 8 fly cell pairs; control, black, n = 6 fly cell pairs). ^∗p < 0.05; ^∗∗p < 0.01, the rank-sum test.

(G) ΔVm as a function of Va during low and high Vf in 5-40^Leg > TNT (n = 8 fly cell pairs) and control (n = 5 fly cell pairs) flies. Vf-dependent Vm offset in 5-40^Leg > TNT flies was smaller than in control flies (^∗∗p = 0, bootstrapping, see also Figure 1).

(H–J) Summary of the findings (H) and the proposed function for the stride-coupled modulation during fast and drifting walking (I) and during fast, straight walking (J) in HS cells.

See also Figure S8.