Fig. 4: Overlapping AHN neural ensembles respond to an object and a predator cue.
a–c catFish analysis of AHNVgat+ neurons activated by exposure to an unfamiliar object or fox urine. a Experimental design and the stimulus presentation order for each group. Animals were sacrificed at the time “0”. b A representative image of an AHN brain section showing Vgat, c-Fos exon, and c-Fos intron in situ signals and their co-localization with DAPI as the counterstain. “1”, “2”, and “3” denote cells that only expressed c-Fos exon, or c-Fos intron, or both. Left, scale bar, 40 μm. Right, scale bar, 10 μm. c Convergence rate as measured by the percentage of c-Fos-intron-positive Vgat + neurons co-expressing c-Fos for each group. Each dot represents the value from an animal. The dashed line indicates the chance level. n = 4 O-F (object – fox urine), 2 F-O (fox urine – object) and 4 O-O (object – object). d–h Single-unit recordings of AHN neurons. d Raster plot (top) and the average (bottom) of the firing of an example single-unit aligned to the onset of object-approaching behavior (left), fox urine in (middle), and fox urine sniff (right). e Heatmap representation of the normalized single-unit responses in Z scores sorted by response magnitude aligned to the behavioral onset, or the time of fox urine in at “0”. n = 63 units from 3 mice. f Venn diagram showing single-units that tuned to “object approach” (green), “fox urine in” (pink), and “fox urine sniff” (purple). The number of single-units in each response category is indicated. g, h The average firing rates of the single-units tuned to initial fox urine in (g) and the object approach (h) during a specific epoch as indicated at the bottom. g. n = 13 units, Wilcoxon matched-pairs signed rank test, object approach, p = 0.03, fox urine in, p = 0.0002, fox urine sniff, p = 0.31. h. n = 9 units. Two-tailed paired t test, object approach, p = 0.006, fox urine in, p = 0.70, fox urine sniff, p = 0.08. *p < 0.05; **p < 0.01; ***p < 0.001. Data are presented as mean values ±SEM.
