Fig. 3: Putative contextual cold engrams are in the DG, LHA and MPO.

a, Genetic strategy. b, Experimental timeline. c, Representative image of eYFP⁺ cells (green). d–g, Comparison between the test cohort (dark blue) and control cohort of eYFP⁺ neurons normalized to area (grey) in the DG (d), the LHA (e), the MPO (f) and the LPO (g). h, Representative image of FOS⁺ cells (red). i–l, Comparison between the test cohort (dark blue) and control cohort (grey) of FOS⁺ neurons normalized to area in the DG (i), the LHA (j), the MPO (k) and the LPO (l). m, Representative image of an eYFP⁺FOS⁺ cell. n–q, Comparison between the test cohort (dark blue) and control cohort (grey) of colabelled neurons in the DG (n), the LHA (o), the MPO (p) and the LPO (q). r–t, Correlation between the percentage of colabelled/eYFP⁺ cells in the DG and oxygen consumption (r) carbon dioxide production (s) and energy expenditure (EE, t) at T1 (orange), CL1 (black) and BL1 (grey). u, Correlation of percentage of colabelled/eYFP⁺ cells between regions during the recall of a cold memory on T1. v, Correlation of percentage of colabelled/eYFP⁺ cells in the control group. c–q, Data are mean ± s.e.m., c–v, n = 6 mice per group. d–g,i–l,n–q, Unpaired t-test. r–t, Simple linear regression. u,v, Pearson’s r correlation analysis. *P < 0.05, **P < 0.01, ***P < 0.001. 4-OHT, 4-hydroxytamoxifen; \({V}_{{{\rm{CO}}}_{2}}\), carbon dioxide production; Ctxt, context; HC, home cage. Scale bars, 250 μm. Illustrations of the transgenic mouse line (a) and the behavioural time line (b) were created with BioRender (https://biorender.com).