Fig. 1. Activity of PACAP^PBL→DR neurons increases in panicogenic conditions.

a, Schematic and representative image of Cre-dependent retrograde expression of mCherry in PACAP^PBL neurons projecting to the CeA, and EYFP expression in DR-projecting PACAP^PBL neurons. Percentages of indicated fluorescent cells in the PBL are represented via a pie chart. Scale bar: 100 µm. Injections were repeated in 3 mice with similar results. b, Schematic and representative images of Cre- and Flp-dependent expression of GCaMP6s, as well as the implantation of fiber in the PBL of an Adcyap1^Cre/+ mouse to monitor PACAP^PBL→DR neuronal activity via fiber photometry. Scale bar: 100 µm. This experiment was repeated on seven mice with similar results. c, Schematic of the CO₂ exposure test. d, Immobile behavior during 10 min of normal air (control condition) or 10% CO₂ exposure. Paired two-sided t-test, P < 0.001. n = 7 mice. e, Change in calcium activity during 10 min of air or 10% CO₂ exposure and corresponding AUC analysis. Paired two-sided t-test, P = 0.0039. n = 7 mice. f, g, Breathing (f, repeated measure two-way ANOVA with Sidak’s multiple comparisons test), and heart rate (g, mixed-effects analysis with Sidak’s multiple comparisons test) changes during CO₂ exposure. n = 14 mice. Respiration responses to both air and CO₂ exposure were taken from the same mice. Lines represent mean responses during each condition in the same mice. h, Schematic of FG-7142 (20 mg/kg) i.p. injection. i, Immobile behavior change following FG-7142 injection. Repeated measure two-way ANOVA with Sidak’s multiple comparisons test. n = 7 mice. Time = 0 is when FG-7142 was injected and recordings started 5 mins after the injection. j, Change in calcium activity following i.p. injection of FG-7142, and corresponding AUC analysis within each 20-min bin. Repeated measure two-way ANOVA with Sidak’s multiple comparisons test. n = 7 mice. k, l, Breathing (k, repeated measure two-way ANOVA with Sidak’s multiple comparisons test), and heart rate (l, repeated measure two-way ANOVA with Sidak’s multiple comparisons test) changes 30 min after FG-7142 injection. n = 9 mice. Data are presented as the mean ± SEM; see also Supplementary Table 3 for statistical details. *P<0.05, **P<0.01, ***P<0.001.