Fig. 4: SUB glutamatergic neuron is the downstream target of the TMN-SUB histaminergic circuit.
From: Histamine-tuned subicular circuit mediates alert-driven accelerated locomotion in mice
HDC-CreERT2 mice were injected with AAV-CAG-FLEX-oChIEF-tdTomato into TMN and mixed AAV-EF1a-DIO-EYFP, AAV-ESARE-ERT2-Cre-ERT2 to label TMN-SUB activated c-fos+ neurons (TMN-SUB sti. activated) in SUB (a), and immunostaining of CaMKIIα/GABA (b), scale bar = 200 μm, n = 4 mice. c, d CaMKIIα-Cre mice were injected with AAV-hSyn-FLEX-mCherry-2A-TVA-2A-RvG and RV-EnvA-△G-EGFP into SUB, with starter cells in SUB (top, scale bar = 200 μm), SUB-projecting TMN neurons (bottom, scale bar = 100 μm), and quantification, n = 4 mice. e HDC-CreERT2 mice were injected with AAV-hSyn-FLEX-ChrimsonR-tdTomato into TMN and AAV-CaMKIIα-GCaMP6s into SUB, scale bar = 100 μm. Fluorescence values (f), heatmaps (g) and quantification (h) of calcium activity during TMN-SUB circuit activation. n = 6 mice, **p = 0.0087. i WT mice were injected with AAV-CaMKIIα-GCaMP6s into SUB, scale bar = 200 µm. j Images and quantification of CaMKIIα staining, scale bar = 50 µm, n = 4 mice. k Representative speed and corresponding calcium activity during locomotion (k1), acceleration (k2, left), and quantification (k2, right) of SUB glutamatergic neuronal activity. n = 16 mice, **p = 0.0017. Fluorescence signal, heatmaps (l), and quantification (m) of SUB glutamatergic neuronal activity during rotarod test. n = 12 mice, *p = 0.0432 B.S vs. 5 rpm, *p = 0.0205 B.S vs. 6 rpm, *p = 0.0229 B.S vs. 7 rpm, **p = 0.0017 B.S vs. 8 rpm. Fluorescence signal, heatmaps (n), and quantification (o) of SUB glutamatergic neuronal activity during treadmill test. n = 20 mice, ***p = 0.0003 Acc vs. B.S, p = 0.4823 Max vs. Acc, &&p = 0.0028 Dec vs. Max. Speed, fluorescence values (p), and quantification (q) of SUB glutamatergic neuronal activity during alert-escape test. n = 8 mice, **p = 0.0051. Two-tailed Student’s t test for (h, k2, o, q) and one-way ANOVA followed by the Dunnett post hoc test for (m). Schematics in a, c, e, i were drew by PowerPoint. Bar graphs represent mean ± SEM. Source data are provided as a Source Data file.
