Fig. 3: The LHA-PnO-spinal pathway is essential for relaying locomotor signals from the hypothalamus to the spinal cord.
a Strategy for terminal stimulation of LHA-MSDB and LHA-PnO pathways. b Left: Locomotion tracing for an example animal of LHA-MSDB (top) or LHA-PnO (bottom) terminal stimulation in the OFT. Right: Quantification of center time and total distance of LHA-MSDB (top) or LHA-PnO (bottom) terminal stimulation in the OFT (n = 6). One-way ANOVA/Tukey’s multiple comparison was applied. ns, not significant; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. Error bars, SEM. c Left: Locomotion tracing for an example animal of LHA-MSDB (top) or LHA-PnO (bottom) terminal stimulation in the EPM. Right: Quantification of center time and total distance of LHA-MSDB (top) or LHA-PnO (bottom) terminal stimulation in the EPM (n = 6). One-way ANOVA/Tukey’s multiple comparison was applied. ns not significant; *p < 0.05; **p < 0.01; ****p < 0.0001. Error bars, SEM. d Strategies and timeline summarizing the experiments of food seeking test with or without depletion of MSDB or PnO projecting LHA neurons. e Left: Trajectory of mice in open-field chambers with food pellets placed in the center with or without the depletion of MSDB-projecting or PnO-projecting LHA neurons. Right: Quantification of entries to center area, total distance and number of food pellets consumed by mice in open-field chambers (n = 6). Student’s t-test (two-tailed, unpaired) was applied. ns, not significant; *p < 0.05; **p < 0.01. Error bars, SEM. f Left: Soma location of MSDB (green) and PnO projecting (red) LHA neurons. Right: Reconstructions of MSDB-projecting neurons in subtype 2 and PnO-projecting neurons in subtype 5. g Strategy for anterograde labeling of glutamatergic PnO neurons. h Representative confocal images showing the expression of mCherry within spinal cord. Scale bar, 200 μm. i Strategy for retrograde labeling glutamatergic spinal cord-projecting PnO neurons. j Representative confocal images showing the expression of EYFP at indicated positions within PnO. Scale bar, 200 μm. k Schematic of three-step monosynaptic rabies virus tracing strategy to demonstrate the circuit of LHA-PnO-spinal cord and trans-synaptically labelled neurons were found in the LHA. Scale bar, 200 μm. l Strategy for activation of PnO-projecting LHA neurons. Speed versus time of single trials (grey lines) and the average (red line) of one mouse. Quantification of total distance (left) and maximum speed (right) of mice before and during optical stimulation (n = 6). Student’s t-test (two-tailed, unpaired) was applied. ****p < 0.0001. Error bars, SEM. m, Strategy for activation of LHA-PnOVglut2-Spinal cord. Speed versus time of single trials (grey lines) and the average (red line) of one mouse. Quantification of total distance (left) and maximum speed (right) of mice before and during optical stimulation (n = 6). Student’s t-test (two-tailed, unpaired) was applied. ****p < 0.0001. Error bars, SEM. Source data are provided as a Source data file.
