Fig. 1: The VTA DAergic neurons act as a central nexus of social reward and drug seeking.

a Schematic of the experimental design. b Number of nose-pokes during cocaine self-administration training (n = 10 male rats, three-way ANOVA, 10 consecutive days measurements from the same animal: F_(9,10) = 2.799, p = 0.062; see Supplementary Table 1A). c Number of nose-pokes during extinction (n = 10 male rats, three-way ANOVA, 14 consecutive days measurements from the same animal: F_(13,6) = 1.233, p = 0.425; see Supplementary Table 1B). d Number of nose-pokes during the relapse test, showing that social reward significantly inhibits cue-induced active nose-pokes (n = 10 male rats, two-way ANOVA: F_(1,18) = 5.857, p = 0.026; see Supplementary Table 1C). e, f Representative photo of GCamp6s expression in the VTA (n = 4 male rats, repeated 4 times independently with similar results). Green: GCamp6s. Pink: Tyrosine hydroxylase, TH. g Schematic of fiber photometry recording. h, k, n Trial-by-trial heatmap representations of calcium signals. Color scales on the right indicate ∆F/F. i, l, o Event plot of average calcium signals aligned to distinct behavioral manipulation. j, m, p Comparison of the area under curve (AUC) between baseline (10 s before stimuli) and stimuli (within 10 s from onset of stimuli) (n = 10 male rats, paired two-tailed t test: SI, t₍₉₎ = 7.004, p < 0.001; RT, t₍₉₎ = 8.131, p < 0.001; SI-RT, t₍₉₎ = 3.043, p = 0.014). q Peak ΔF/F quantification (n = 10 male rats, one-way ANOVA with Bonferroni multiple comparisons test, F_(2,18) = 4.765, p = 0.022; RT vs SI-RT, p = 0.109). r AUC quantification (n = 10 male rats, one-way ANOVA with Bonferroni multiple comparisons test, F_(2,18) = 11.08, p = 0.007; RT vs. SI-RT, p = 0.002). All the data are presented as mean ± SEM. 95% confidence interval was used for all statistical analyses in this figure. a, e: Created in BioRender. Xiaoxing, L. (2026) https://BioRender.com/hqs0eg6. ^*p < 0.05, ^**p < 0.01, ^***p < 0.001.