Fig. 1: Properties of the LPB → POA/DMH pathways and their sensitivity to temperature.

a, b Whole-brain projection pattern of LPB^Vglut2 neurons viewed using AAV-mediated axonal tracing. The injection site and representative axonal images in the POA and the DMH are shown in (b). The scale bar is with the image (as with all brain images). B, bregma; BNST, bed nucleus of the stria terminalis; CeA, central nucleus of the amygdala; 3 V, third ventricle; LPB, lateral parabrachial nucleus; PAG, periaqueductal gray matter; VTA, ventral tegmental area; LPO, lateral preoptic area; LH, lateral hypothalamus; PVT, paraventricular thalamic nucleus; MPA, medial preoptic area; MnPO, median preoptic area; VLPO, ventrolateral preoptic area; VMPO, ventromedial preoptic nucleus; VMH, ventromedial hypothalamic nucleus; POA, preoptic area; DMH, dorsomedial hypothalamic nucleus; DMV, dorsomedial hypothalamic nucleus, ventral part; DMD, dorsomedial hypothalamic nucleus, dorsal part. This experiment was repeated at least 4 times independently with similar results. c, d Mapping POA-projecting and DMH-projecting LPB^Vglut2 neurons. LPBc, lateral parabrachial nucleus, central part; LPBd, lateral parabrachial nucleus, dorsal part; LPBel, lateral parabrachial nucleus, external and internal part; scp, superior cerebellar peduncle. e–h Overlap between DMH/POA-projecting LPB^Vglut2 neurons and warmth (e, f) or cold (g, h) induced cFos. The experiments in (e) and (g) were repeated 3 times independently with similar results, respectively. i The ratio of warm- and cold-activated DMH-projecting LPB^Vglut2 neurons (20 slices each from 3 mice). j Excitatory postsynaptic currents (EPSCs) were recorded randomly from DMH neurons after photoactivation of LPB^{Vglut2 & ChR2} terminals in the DMH (blue, 7 mW, 10 ms). EPSCs were blocked by GluR antagonists D-AP5 and CNQX. The mean latency of responsive neurons is shown on the right (n = 17 neurons). k The EPSC response rate of DMH neurons to light stimulation (n = 3 mice). A total of 17 responsive neurons out of 51 randomly recorded DMH neurons were from three mice. All data are the mean ± sem, and were analyzed using the unpaired t-test in (i). P-values were calculated based on statistical tests in Supplementary Table 2. ****p ≤ 0.0001. Source data are provided as a Source data file.