Figure 1.

HS cells contribute to steering in high- but not low-speed walking bouts

(A) Schematic of brain-body interactions across timescales.

(B) Schematic of the anatomy (left) and physiological properties of HS cells during walking (right).

(C) Change in membrane potential (ΔVm) as a function of the angular velocity (Va) of the fly in walking bouts with low (gray) or high (black) forward velocity (Vf) (p = 0.79 for the slope; p = 0 for the offset difference between curves, grand mean ± SEM, n = 556 bouts from 9 flies, bootstrapping method).

(D) Conditional unilateral inhibition in HS cells (right). Example time series of Vm, Va, and Vf with a single histamine application in HS cells expressing the Ort histamine receptor.

(E) Left, Vm, Va, and Vf traces in experimental flies (grand mean ± SEM, n = 11 flies) triggered at histamine injection during low (blue) or high (orange) Vf. Right, mean histamine-induced change in Va (ΔVa) per fly. Lines connect the same individual (p = 0.019, n = 11 flies, the signed-rank test).

(F) Same as (E) but for controls (p = 0.36, n = 9 flies, signed-rank test).

See also Figure S1.