Fig. 1: Strong temporal correlation of AHN^Vgat+ neuron activity with object-evoked avoidance behavior in a modified open field paradigm.

a We modified the open field test with the introduction of an unfamiliar object 10 min after the initial exploration. “1”, “2”, and “3” denote the “center”, “middle”, and “peripheral” zone of the open field. The example trajectory (bottom) and the quantification (right) show that animals spent more time in the peripheral zone away from the center after object introduction. n = 6 mice. Wilcoxon matched-pairs signed rank test, center, p = 0.03, middle, p = 0.03, peripheral, p = 0.03. b In control assays, animals were allowed to explore the open field for 20 min. The example trajectory and the quantification (right) show similar time spent in all three zones in the first and second 10 min of the open field test. n = 6 mice. Two-tailed paired t test. c Schematic illustration of the “hypothalamus predator defense circuit”. d A representative image showing the fluorescent in situ signals of Vgat and Vglut2 mRNA in AHN. Scale bar, 200 μm. e Left, the strategy to monitor GCaMP6s signals in AHN^Vgat+ neurons. Right, a representative image showing restricted GCaMP6s expression in AHN. Scale bar, 200 μm. f Average ΔF/F values detected in the “center”, “middle” and “periphery” zone before and after object introduction in GCaMP6s animals. n = 14 mice. Center, two-tailed paired t test, center, p = 0.0003; middle and peripheral, Wilcoxon matched-pairs signed test, p = 0.0004 and p = 0.0009, respectively. g A representative trace of ΔF/F signals (green, top) aligned to the relative distance (black, bottom) between a GCaMP6s animal and the object. Red dashed lines denote the onset of approach bouts. h, i Average ΔF/F values of GCaMP6s signal aligned to approach (h) or retreat onset (i) at the time “0”. Shades indicate the SEM. j Correlation between the GCaMP6s ΔF/F value at the end of an approach and the latency to initiate the following approach. n = 351 bouts from 14 mice. Spearman correlation. k Correlation between average approach-end GCaMP6s ΔF/F value and the time animals spent in the periphery zone. n = 26 trials from 14 mice. Pearson’s correlation. *p < 0.05; ***p < 0.001. Data are presented as mean values ±SEM.