Extended Data Fig. 2. Fat activates cNST neurons.

a–d, Strong Fos labelling is observed in neurons of the cNST (Bregma −7.5 mm) in response to ingestion of fat stimuli (panels c-d), but not in control animals (10% mineral oil, panel b). Stimulus: 10% linoleic acid (LA), 10% oleic acid (OA). Scale bars, 200 µm. e, Quantification of Fos-positive neurons. ANOVA with Tukey’s HSD test against mineral oil (MO, n = 5 mice): P = 3.4x10⁻⁵ for linoleic acid (LA, n = 5 mice), P = 3.9x10⁻⁵ for oleic acid (OA, n = 5 mice). Values are mean ± s.e.m. f–i, TetTox silencing of fat-TRAP cNST neurons does not impair immediate attraction to sweet (3 mM AceK; f, g) or fat (1.5% IL; h, i). Two-tailed paired t-tests: sweet versus water, wild type, n = 10, P = 1.1x10⁻⁷; TetTox n = 9, P = 1.1x10⁻⁶. For fat versus water, wild type, n = 10, P = 6.8x10⁻⁵; TetTox, n = 9, P = 1.7x10⁻⁵. Values are mean ± s.e.m. j-k, Intragastric infusion with fat activates cNST neurons. j, Direct intragastric infusion of fat (IL) but not control (PBS) robustly activates the cNST. Scale bars, 100 µm. k, Quantification of Fos-positive neurons in animals infused with control and IL stimuli, Two-sided Mann–Whitney U-test between control and Intralipid (n = 5 mice), P = 8x10⁻³. l, We note that we often observe variable labeling in the area postrema (see Fig. 1c and panel jhere), but such labeling is independent of oral versus intragastric infusion⁴. The bar graphs show the quantification of Fos⁺ neurons in the area postrema (AP) and cNST (Fig. 1d) in response to free licking of IL (90 min) versus intragastric infusion (n = 5 mice). cFos in cNST: oral 105 ± 6, infusion 99 ± 6, cFos in AP: oral 93 ± 15, infusion 90 ± 12. The equivalent area of the cNST (bregma − 7.5 mm) was processed and counted for the different experiments. Two tailed unpaired t-test, cNST: P = 0.54; AP: P = 0.86. Values are mean ± s.e.m.