Fig. 1: Anatomical and functional evidence of the co-expression between mGlu5 and SST.
From: Loss of mGlu5 receptors in somatostatin-expressing neurons alters negative emotional states
a Sagittal section of a WT mouse brain immunoreactive for mGlu5 (top) and SST (bottom). Scale bar: 1 mm. b Higher magnification of the hippocampus. Scale bar: 500 μm. c Representative image of mGlu5 (in magenta) and SST (turquoise) co-expression in an IN in the stratum oriens (Or) of the mouse HPC. Of note it is the high intracytoplasmic immunofluorescence signal for mGlu5 in comparison to pyramidal neurons (marked with *), that show mostly labeling associated with the plasma membrane. Scale bar: 5 μm. d Electron micrograph of a CA1 oriens/alveus IN characterized by strong SST immunoreactivity (DAB electron-dense deposits indicated by arrowheads) in the Golgi and ER. The inset shows a dendrite of this IN, in which most of the immunometal particles identifying mGlu5 are intracytoplasmatic rather than associated with the plasma membrane (arrows). Abbreviations: D, dendrite; ER, endoplasmic reticulum; G, Golgi apparatus; N, nucleus. Scale bar: 5 μm; scale bar inset: 1 μm. e Example image of mGlu5 and SST expression in the mouse LS depicting the absence of co-localization. Scale bar: 5 μm. The thickness of the confocal z-stacks: c 5.02 μm; e 3.6 μm. f Representative example of a biocytin-filled PN (scale bar: 100 μm) with its respective DIC image (scale bar: 10 μm) and membrane responses to current injections. SO, stratum oriens; SP, stratum pyramidale; SR, stratum radiatum. g Example trace displaying PN membrane depolarization upon DHPG application and inhibition by MTEP pre-treatment. h Quantification of DHPG-mediated membrane potential change in PNs in the absence or presence of MTEP (n = 5). One-way RM ANOVA, Treatment F4,16 = 4.29, *p < 0.05. Bonferroni multiple comparisons test: *p < 0.05, **p < 0.01. Plot represents mean ± SEM. i Example image of a biocytin-filled CA1 stratum oriens SST+ IN with its respective DIC, Ai14-tdTomato expression and membrane responses to current injections. j Example trace displaying the membrane depolarization upon DHPG application and inhibition by MTEP pre-treatment in the same SST+ IN shown in i. k Quantification of DHPG-mediated membrane potential change in CA1 SST+ INs in the absence or presence of MTEP (n = 6). One-way RM ANOVA, Treatment F4,20 = 4.75, **p < 0.01. Bonferroni multiple comparisons test: *p < 0.05, **p < 0.01. Plot represents mean ± SEM. l Example image of a biocytin-filled CA1 SST+ IN with its respective DIC, Ai14-tdTomato expression, and membrane responses to current injections. m Example trace displaying the membrane depolarization upon DHPG infusion of the same SST+ IN shown in l in the presence of the mGlu1 NAM JNJ16259685. n Quantification of DHPG-mediated membrane potential change in hippocampal SST+ INs in the presence of JNJ16259685 (n = 6). Wilcoxon matched-pairs rank test, W = 21, *p < 0.05. Data are shown as mean ± SEM; individual data points are also provided. *p < 0.05.
