Extended Data Fig. 8: Retrieval of a cold memory does not correlate metabolism with Fos⁺ in CA3, MPO or LPO, or increase neural activity in every region.

Correlation between oxygen consumption and Fos⁺ cells in a, CA1, b, CA3, c, MPO, and d, LPO between mice during BL1 (white), CL1 (dark blue) and T1 (light blue). e Representative image of hippocampal slice with Fos⁺ cells (red) and DAPI⁺ cells (blue). f Experimental timeline for tissue collection. g Diagrammatic representation of the automated brain-wide Fos detection pipeline used to identify Fos⁺ cells in multiple brain regions simultaneously. Comparison of Fos⁺ neurons normalized to area in the h, VMH i, DMH j, PVi k, ARH l, BST m, BLA n, BMA o, CeA p, AI and q, SSp between mice housed during BL1 (white), CL1 (dark blue) and T1 (light blue). Correlation matrix of Fos⁺ cells normalized to area during r, baseline day (BL1), s, cold training day (CL1) and t, the recall of a contextual cold memory on test day, with positive (red) and negative (grey) correlations. h-t, Data shown as mean ± SEM, a-d, h-t n = 3-9 mice per group. a-d, Simple linear regression with slope comparison, h-q, One-way ANOVA. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. BL1, baseline 1; T1, Test 1; CL1, cold 1; CA3, cornu ammonis 3; CA1, cornu ammonis 1; VO₂, oxygen consumption; MPO, medial preoptic area; LPO, lateral preoptic area. BL1, baseline 1; T1, Test 1; CL1, cold 1; VMH, ventromedial hypothalamic nucleus; DMH, dorsomedial nucleus of the hypothalamus; AI, agranular insular area; SSp, primary somatosensory area; PVi, periventricular hypothalamic nucleus -intermediate part; ARH, arcuate hypothalamic nucleus; BST, bed nuclei of the stria terminalis; BLA, basolateral amygdalar nucleus; BMA, basomedial amygdalar nucleus; CeA; central amygdalar nucleus; DG, dentate gyrus; CA3, cornu ammonis 3; CA1, cornu ammonis 1; LHA, lateral hypothalamic area. Schematics in f and g created with BioRender (https://biorender.com).