Fig. 2. Activity of LH^LepR neurons is time-locked to seeking and consummatory behaviours.

a Schematic of virus injection/fibre insertion for fibre photometry in LH from LepR-cre mice. b A representative image validates GCaMP6s expression in LepR neurons and optical fibre tract above the LH. Scale bar: 500 µm. The experiment was repeated 5 times independently with similar results. fx, fonix. c Schematic of the consummatory behaviour test 1 (obtainable). d Representative calcium traces from LH^LepR neurons. Yellow shaded box: from the moment of food contact to the end of food consumption. e Average Z-score from LH^LepR calcium response aligned to contact with food (5 mice, 22 trials). f Quantification of Z-score in calcium signal change from (e). Comparison between baseline (−8 to −7 s) and after contact (9 to 10 s). g Heatmap depicting normalised LH^LepR neural activity aligned to the moment of contact with food. h Schematic of the multi-phase test 2. i, j Representative calcium traces (i) and average Z-score (j) from LH^LepR neural calcium signal response aligned to voluntary seeking initiation (4 mice, 67 trials). k Quantification of Z-score in calcium signal change from (j). Comparison between baseline (−8 to −7 s) and after voluntary seeking behaviour (2 to 3 s). l Heatmap depicting normalised LH^LepR calcium signal aligned to voluntary seeking behaviour. m Representative neural onset of LH^LepR calcium signal aligned to the onset of voluntary seeking behaviour. Yellow line near –5 s is the neuronal onset timing. n, o Cumulative probability distribution (n) and histogram (o) of LH^LepR neural onset (4 mice, 66 trials). Neural onset occurred at −5.623 ± 0.418 s. p Schematic and schedule of the multi-phase test 1. q, r Dynamic feeding phase before conditioning (q) and after conditioning (r). s Time from food accessibility to food contact before and after conditioning (n = 4 mice). t, u Representative calcium signal of LH^LepR neurons aligned to food accessibility (left) and quantification of Z-score in calcium signal change (right) before (t) and after (u) conditioning. Comparison between baseline (−2 to −1 s) and after locomotion or seeking behaviour (1 to 2 s). Two-sided paired t-test; n.s., p > 0.05 (t), *p = 0.02 (u). Data are mean ± s.e.m. See Supplementary Table 1 for statistics. Source data are provided as a Source data file. The schematics in a, c, h, p, q and r were created using BioRender.