Fig. 1

Serotonin-responsive neurons in the CeA and PBNLE are labeled in TRAP2 mice. (A) Schematic illustrating the TRAP system used for selective labeling of serotonin-responsive neurons. (B–D) In TRAP2 mice, intradermal serotonin injection significantly increased the number of tdTomato⁺ (red) neurons in the CeA compared to PBS injection (n = 2–3 sections from 3–4 mice). Scale bar, 200 μm. (E–G) Similarly, intradermal serotonin injection in TRAP2 mice resulted in a significant increase in tdTomato⁺ (red) neurons in the PBNLE compared to PBS injection (n = 2–3 sections from 4–7 mice). Scale bar, 200 μm. Data are presented as mean ± SEM. Statistical significance: *p < 0.05 (two-tailed unpaired t-test). P-values were corrected for multiple comparisons using Bonferroni correction.