A Surgical schematic and experimental timeline for LHb 5HT2c deletion. B Representative viral infection for LHb 5HT2c deletion experiments. Similar viral infection was reproduced in n = 66 mice. C Social preference in the 3-chamber sociability test, females. D Social novelty preference in the 3-chamber sociability test, females, pDiDXvirus = 0.022, pDiD = 0.0670, pvirus = 0.1352. E Social preference in 3-chamber sociability test, males, pvirus = 0.0334. F Social novelty preference in 3-chamber sociability test, males. G Acoustic startle behavior, females (10 trials/dB), three-way repeated measures ANOVA followed Holm-Sidak’s post-hoc, pvirusXdB = 0.0112, pDiD = 0.0908, pvirusXdBXDiD = 0.087. H Acoustic startle behavior, 120 dB only, females (10 trials), pvirus = 0.0417. I Acoustic startle behavior, males (10 trials/dB), three-way repeated measures ANOVA followed by Holm-Sidak’s post-hoc, pvirusXDiD = 0.0104, pvirusXdBXDiD = 0.006. J Acoustic startle behavior 120 dB only, males (10 trials), pvirusXDiD = 0.0059. K Surgical schematic and experimental timeline for BNST 5HT2c deletion. L Representative viral infection for BNST 5HT2c deletion experiments. Similar viral infection was reproduced in n = 61 mice. M Social preference in the 3-chamber sociability test, females, pvirus = 0.0329. N Social novelty preference in the 3-chamber sociability test, females, pDiDXvirus = 0.0019. O Social preference in 3-chamber sociability test, males. P Social novelty preference in 3-chamber sociability test, males, pDiD = 0.062. Q Acoustic startle behavior, females (10 trials/dB), three-way repeated measures ANOVA, Holm-Sidak’s post-hoc. R Acoustic startle behavior, 120 dB only, females (10 trials), three-way repeated measures ANOVA, Holm-Sidak’s post-hoc. S Acoustic startle behavior, males (10 trials/dB), three-way repeated measures ANOVA followed by Holm-Sidak’s post-hoc, pvirus = 0.07, pvirusXdB = 0.1753. T Acoustic startle behavior 120 dB only, males (10 trials). LHb females, GFP: water n = 8 mice, DiD n = 8 mice; Cre: water n = 9 mice, DiD n = 6 mice. LHb males, GFP: water n = 8 mice, DiD n = 9 mice; Cre: water n = 9 mice, DiD n = 9 mice. BNST females, GFP: water n = 7 mice, DiD n = 9 mice; DiD water n = 7 mice, DiD n = 8 mice. BNST males, GFP: water n = 7 mice, DiD n = 9 mice; Cre: water n = 8 mice, DiD n = 6 mice. Unless otherwise stated, statistical comparisons were performed using two-way ANOVA followed by Holm-Sidak’s post-hoc. All data are presented as mean ± SEM. & denotes effect of DiD, # denotes interaction (DiD × virus), * denotes post-hoc effects. Source data are provided as a Source Data file. Created with Biorender.com.