Extended Data Fig. 16: DP regulation of preautonomic outputs via LHA.

a, AAV-RFP/FG coinjection in LHA reveals dense retrograde labelling in MPF, AId, and TTd. Notably, DPs still contains the densest labelling (left panels). Anterogradely labelled axons project to widespread targets, including forebrain, thalamus, PAG, DMX, NTS, and parvicellular reticular nucleus (PARN). b, AAV1-Cre was injected into the DP and Cre-dependent AAV-FLEX-GFP into LHA (schematic, upper left) enabling examination of the downstream projections of DP → LHA neurons. b1, the AAV1-Cre DP injection site; b2-b3, AAV-FLEX-GFP LHA injection site. Cre-labelled starter cells express GFP and send broad axons to brain structures that regulate autonomic and behavioural activities (b4-b19), including BST, SI, PAG, PB, DMH/NTS, ventromedial medulla (RM, RPA), and reticular nuclei (PARN, IRN, PGRN near AMB). Compared to non-selective LHA projections (panel a), these DP-recipient LHA neurons show sparse thalamic projections, with the notable exception of dense input to the lateral habenula (LH; b9). See Supplementary Table 1 for abbreviations. c, Microphotographs showing axonal labelling in DMX following PHAL injections into ILA. Scale bars = 500 µm. d, Schematic illustrating the neural network through which the DPs and ILA regulate vagal parasympathetic outputs.