Fig. 6: A descending control of VMH-sympathetic nerve-liver activity mediates CRH effect on stress glucose in VMH.

a Strategy for design of Crhr2-Cre mice by using CRISPR-Cas9 system. b Representative image of EGFP co-localiztion with Crhr2 mRNA in the VMH. c, d Schematic of anterograde tracing virus injection (c) and representative image showing CRHR2⁺ afferents in Rpa (d). e Paradigm for photo-stimulation of CRHR2 terminals in the Rpa. f Glucose levels increased after light stimulation of VMH^CRHR2→Rpa, *p = 0.043, control (n = 7) vs ChR2 (n = 7). g Schematic of photo-stimulation of VMH^CRHR2→Rpa in brain slices. h Example traces for light-evoked time-locked EPSC in the Rpa neurons. i Paradigm for photo-inhibition of VMH^CRHR2→Rpa during footshock. j Footshock-induced increases in fast glucose levels in the control group ($$p = 0.002), which is blunt by photo-inhibition of CRHR2 terminal in the Rpa (*p = 0.015), n = 6 per group. k Paradigm for tracing of VMH^CRHR2+→Rpa→IML. l Representative image showing IML-projecting neurons (red) in Rpa, which is surrounded by CRHR2⁺ afferents (green) from VMH. m Schematic of identifying the connection between VMH^CRHR2+ neurons and IML-projecting neurons in Rpa. n Photo-stimulation evoked synaptic currents in IML-projecting neurons of Rpa (in 100 µM PTX), indicating an excite projection from VMH^CRHR2 to Rpa^{IML-projecting}. o Statistics of total responding cells showing that over 38% IML-projecting neurons received direct projection from VMH^CRHR2. p Schematic of opto-stimulation of PVN^CRH → VMH after liver denervation. q Denervation of liver diminished activation of PVN-VMH induced increases on blood glucose levels. r Schematic of footshock stress after liver denervation. s Stress-induced increase on fast glucose levels in the sham group ($$p = 0.002, compared to baseline), which can be suppressed by liver denervation, *p = 0.02, sham (n = 7) vs denervation (n = 6). Multi-time point data were analyzed by two-way repeated-measures ANOVA with LSD post hoc comparison, otherwise use two-sided t test. All data shown as means ± SEM. Source data are provided as a Source Date file.