Figure 1.

Preparatory Activity in the Anterolateral Motor Cortex

(A) Schematic of the virtual reality setup.

(B) Running speed profiles for all mice from Figures 1 and 2 (black curves, 21 expert mice) and population average (orange trace, shading is SD). Red vertical dashed line indicates reward.

(C) Same as (B) but for lick rate.

(D) Schematic showing recording location in the anterolateral motor cortex (ALM).

(E) (From top to bottom) Structure of visual textures lining the virtual corridor walls with the red dotted line indicating the position of reward delivery 40 cm from the appearance of the checkerboard pattern (scale bar), average (black line) and SD (shaded area) of running speed, lick rate, and Z-scored firing rate of all ALM neurons exhibiting task modulation, as a function of position in the virtual corridor. The visual patterns are aligned to the position at which they fully appear in the field of view of the mice (i.e., when they reach the back edge of the monitors).

(F) Summary ALM neuron classification (n = 169 neurons, 6 mice).

(G) Running speed (top) and lick rate (bottom) around reward time for an example recording. Black line is the average; gray shaded area is the SD.

(H–J) Spiking activity from example neurons in ALM, classified as type 1 (H), type 2 (I), and type 3 (J) from the same recording as in (G). (Top) Spike raster for 20 consecutive trials is shown. (Bottom) Average response profile centered on reward delivery is shown from the same trials shown above. The vertical dotted lines across (G)–(J) indicate reward time.

(K) Mean Z-scored firing rate of reward-time-modulated ALM neurons centered on reward time represented by the white vertical line. Within types, neurons (one per line) are sorted by their mean Z score value in the last second before reward.

(L) Average cross-covariance between firing rates of all neurons (grouped by type) and lick rate for −2- to 2-s time lags (10-ms binning). The shaded areas represent SEM.

(M) Cross-covariance between firing rates and running speed, description as in (L).

(N) Average (line) and SD (shaded area) centered on reward delivery (vertical shaded area represents time window from reward to reward + 1 s) for, from top to bottom, running speed, lick rate, and firing rate (Z scored), averaged for all type 1, type 2, and type 3 neurons.

(O–Q) Same as in (N) for responses centered on deceleration events outside of the reward zone (O), first lick of a train outside of the reward zone (P), and the appearance of the first non-rewarded checkerboard visual stimulus (Q) at the front edge of the monitors (see Figure S3).