Journal: bioRxiv
Article Title: Vagal dopaminergic afferents link interoception to trigeminal pain modulation
doi: 10.64898/2026.03.27.714928
Figure Lengend Snippet: ( A ) Experimental timeline. AAV vectors were injected into the nodose ganglion (NG) 28 days before the forced mouth-opening (FMO) procedure. FMO was performed for 3 h per day across five consecutive days. Facial mechanical thresholds (von Frey), grimace scores (MGS), and open-field activity were assessed at baseline and multiple time points after FMO. C21 was administered intraperitoneally once daily for 2 days beginning on day 1 post-FMO, and conditioned place-preference (CPP) testing was conducted between days 9–13 post-FMO. ( B ) Representative confocal fluorescence images of NG showing mCherry reporter expression following viral infection, with nuclei counterstained with DAPI. ( C ) Facial withdrawal thresholds across different Cre lines and wild-type after FMO. C21 was administered intraperitoneally after von Frey testing once daily on day 1 and 2 after FMO. Cre-driver mice received nodose ganglion injection of AAV-DIO-hM3Dq and control mice received AAV-DIO-mCherry, both received intraperitoneal C21 after injection. ( D ) Facial withdrawal thresholds in DAT-Cre mice or wild type mice with or without intra-TMJ injection of C21. DAT-cre mice received nodose ganglion injection of AAV-DIO-hM3Dq, followed by intra-TMJ injection of C21 or vehicle. Data are presented as mean ± s.e.m.: *p < 0.05, **p < 0.01, ***p < 0.001 (two-way ANOVA followed by Tukey’s multiple-comparisons test). ( E ) Representative facial images of WT and DAT-Cre mice before and after FMO with or without C21 treatment. ( F ) Quantification of spontaneous pain using the Mouse Grimace Scale (MGS). DAT-Cre + C21 mice exhibited significantly reduced MGS scores on day 5 and day 7 post-FMO compared to control groups. Data are mean ± s.e.m.; **p < 0.01, ***p < 0.001, ###p < 0.001 (two-way ANOVA followed by Tukey’s multiple-comparisons test).
Article Snippet: For selective activation of dopaminergic vagal neurons, AAV-DIO-hM3Dq (#44361; Addgene) or AAV-DIO-mCherry (control) (#50459; Addgene) was injected unilaterally into the right nodose ganglion of Cre-driver mice.
Techniques: Injection, Activity Assay, Conditioned Place Preference, Fluorescence, Expressing, Infection, Control
