Figure S3.

Subpopulation of MLR neurons recruited during locomotion, related to Figure 3

(A) Left: Experimental approach used for calcium imaging of spinally-projecting glutamatergic MLR neurons and fraction of MLR > SC neurons positively modulated by locomotion (39.3%; 56 neurons, n = 7 mice). Middle: Graphs depicting modulation indices during open field locomotion of MLR > SC neurons in rising order (neurons positively modulated by locomotion in magenta dots; all other neurons shown as gray dots). Right: Baseline subtracted average fluorescence (± SEM) of locomotion-tuned MLR > SC neurons, aligned to locomotion onset.

(B) Left: Experimental approach used for calcium imaging of Rbp4 transgene positive MLR neurons and fraction of MLR-Rbp4 neurons positively modulated by locomotion (19.9%; 152 neurons, n = 4 mice). Middle: Graphs depicting modulation indices during open field locomotion of MLR-Rbp4 neurons in rising order (positively modulated neurons are depicted in cyan; all other neurons shown as gray dots). Right: Baseline subtracted average fluorescence (± SEM) of locomotion-tuned MLR-Rbp4 neurons, aligned to locomotion onset.

(C, D) Two representative locomotion-tuned example neurons (C: MLR > SC; D: MLR-Rbp4) from our experimental dataset. Speed traces (magenta), locomotor bout time windows (transparent magenta boxes) and Z-scored fluorescence (black) are depicted. Note low fluorescence for both neurons in non-locomotion time windows in the center.

(E) Anatomical reconstruction of GRIN lens placements for MLR > SC (left) and MLR-Rbp4 (right) experiments shown on corresponding atlas sections (Bregma level indicated).

See also Figure S4.