Association of VGLUT2-immunoreactive boutons with substance P (SP) cells. (A) Scatter plot showing the percentage of Homer puncta on the 36 SP cells analysed in this study that were associated with VGLUT2-immunoreactive boutons. For comparison, corresponding results are also shown for 16 GRP-eGFP cells that were analysed as part of a separate study (Bell et al (2020)). The difference between these two populations is highly significant (p < 0.0001; Mann-Whitney U test). (B) comparison of the percentage of VGLUT2-immunoreactive boutons associated with Homer puncta on the SP cells that were positive for 4 different markers (9 cells examined in each case), compared with the percentage of VGLUT2 boutons in the vicinity of each cell that were positive for the corresponding marker. The first column shows VGLUT2 boutons that were eGFP-positive in Tac1Cre;GRP::eGFP mice. The remaining columns show VGLUT2 boutons in Tac1Cre mice that were immunoreactive for substance P (SP), neurotensin (NTS) or neurokinin B (NKB), respectively. The differences for eGFP-positive boutons in the Tac1Cre; GRP::eGFP mice and for SP boutons in the Tac1Cre mice were both significant (p = 0.004 and p = 0.018, respectively, Wilcoxon matched pairs tests).