Fig. 5: Repetitive optogenetic stimulation of VP ChAT neurons causes depression- and anxiety-like behaviours.

a–d Tests for emotion-like behaviours were conducted in Sham mice (n = 13–15) and SNI mice (n = 15–20). a Tail suspension test (TST). t = 8.48, df = 28, P < 0.0001. b Forced swim test (FST). t = 5.79, df = 29, P < 0.0001. c Elevated plus maze (EPM). Time in open arms: t = 3.55, df = 29, P = 0.0013. Open-arm entries: t = 2.57, df = 29, P = 0.016. d Open field arena (OFT). Immobility: t = 0.73, df = 26, P = 0.47. Time in center: t = 3.88, df = 26, P = 0.0006. e Schematic diagram for repetitive (3-day) unilateral photo-stimulation of VP ChAT neurons in ChR2 and eGFP mice. f Immobility time in the TST. t = 6.13, df = 19, P < 0.0001. eGFP: n = 10; ChR2: n = 11. g Immobility time in the FST. t = 12.80, df = 21, P < 0.0001. eGFP: n = 11; ChR2: n = 12. h Time in and entries into the open arms of the EPM. Time in open-arms: t = 5.35, df = 19, P < 0.0001; Open-arm entries: t = 3.65, df = 19, P = 0.002; Distance in EPM: t = 0.13, df = 19, P = 0.90. eGFP: n = 10; ChR2: n = 11. i–k Representative images and summary showing c-Fos-positive ChAT and non-ChAT neurons in the VP in ChR2 mice 3–4 days after discontinuation of repetitive photo-stimulation of the VP. j ChAT neurons. Left: t = 4.04, df = 28, P = 0.0004. Right: t = 9.96, df = 28, P < 0.0001. n = 15 sections from five mice in each group. k Non-ChAT neurons. Left: t = 3.4, df = 22, P = 0.0026. Right: t = 7.93, df = 22, P < 0.0001. n = 12 sections from five mice in each group. Two-tailed t-tests were used for (a–d, f–h, j–k). **P < 0.01; ns not significant. Contra contralateral, Ipsi ipsilateral.