Figure 3. LH^LEPR neuronal activity discriminates reward predictive from non-predictive cues.

(A) Schematic of deep brain calcium imaging.

(B) Representative images of GRIN lens placement and field of view from Slc32a1^Cre and Lepr^Cre mice. Scale bars: top, 500 μm; bottom, 100 μm.

(C) Slc32a1^Cre (n = 9) and Lepr^Cre (n = 8) mice used for functional imaging experiments on average performed most post-CS licks following CS⁺ trials.

(D) Normalized Ca²⁺ traces of individual LH^VGAT neurons on CS⁺ or CS⁻ trials. Vertical dashed lines indicate the beginning of the CS and outcome epochs. Horizontal dashed lines indicate groupings of neurons according to the epoch of maximal activity.

(E–G) Normalized traces of CS⁺ (orange) and CS⁻ (gray) trials of (E) pre-responsive, (F) cue-responsive, and (G) reward-responsive LH^VGAT neurons.

(H–K) Similar to (E)–(G), except for LH^LEPR neurons.

(L) LH^LEPR activity during the CS epoch discriminated trial types whereas LH^VGAT activity did not. *p = 0.017, ****p < 0.0001.

(M) Maximal activity of individual LH^VGAT neurons on CS⁺ and CS⁻ trials, without matching the sampled time bin. Dashed lines indicate sample CS⁺/CS⁻ ratios. The LH^VGAT centroid ratio was 1.26, indicating slight preference for CS⁺ trials.

(N) Similar to (M), but for LH^LEPR neurons; the centroid ratio was 2.00, indicating large preference for CS⁺ trials.

(O) CS⁺ selectivity index (CS⁺ response/ΣCS responses) was higher for LH^LEPR than LH^VGAT neurons (p = 0.0034).

Data represented as means ± SEMs.

See also Table S1 for full statistics.