Examples of connections resulting from tracer injection sites including the LPO and neighboring regions (control injections). (a) An AAV‐tdTomato injection site in the LPO (#SW181214‐01B). (b) Anterograde AAV‐tdTomato labeling in the lateral habenula (LH) arising from (a). (c) A PHAL injection site mostly in the LPO, with lateral extension into parts of the amygdala (#SW181214‐02B). (d) Anterograde PHAL labeling in the LH arising from (c). (e) Extensive labeling in medial (MEA), basomedial (BMA), and cortical (COA) amygdala nuclei arising from (c). (f) Moderate AAV‐tdTomato anterograde labeling in the MEA but comparatively weak BMA and COA labeling arising from a restricted LPO injection (injection site shown in Figure 2a). (g) An AAV‐tdTomato injection site mostly in the LPO (SW181214‐04B). (h) and (i) Very strong anterograde labeling in medial septal (MS) and diagonal band (NDB) nuclei (h), and LH (i) arising from (g). (j) A CTB‐647 injection site mostly within the medial preoptic area (MPO), with slight LPO inclusion (#SW181221‐01A). (k) Abundant retrograde labeling in the lateral septal nucleus rostral part (LSr), and less abundant labeling in the LS caudal part (LSc), BSTpr, and MEPO arising from (j). (l) Abundant VMH retrograde labeling arising from (j), in contrast to relatively weak retrograde VMH labeling resulting from an LPO‐restricted CTB‐647 injection (injection site shown in Figure 2b). See text for further details. Dashed lines indicate approximate cytoarchitectural boundaries corresponding to reference atlas parcellation. Additional abbreviations: aco, anterior commissure (olfactory limb); AHNa, anterior hypothalamic nucleus anterior part; ARH, arcuate hypothalamic nucleus; BSTpr, bed nuclei of terminal stria principal nucleus; cc, corpus callosum, DG, dentate gyrus; fx, fornix; LSv, lateral septal nucleus ventral part; MH, medial habenula; och, optic chiasm; SCH, suprachiasmatic nucleus; SF, septofimbrial nucleus; V3, third ventricle; VL, lateral ventricle; VMH, ventromedial hypothalamic nucleus. Scale bars are 500 μm in a, c, g, h, and j; 250 μm in b, d, e, f, i, k, l, and m