Extended Data Fig. 2: MPOA^Gal projections in males and downstream connectivity.

a, Synaptophysin–GFP (Syn–GFP) labelling of presynaptic sites in MPOA^Gal projections. b, Representative MPOA^Gal projections from a virgin male, identified by tdTomato fluorescence. c, Representative MPOA^Gal projections, identified by tdTomato fluorescence, after viral injection into the left MPOA. d, Fos⁺ fractions of virally labelled MPOA^Gal projections in fathers (n = 6, 3, 4, 3, 3, respectively, from top to bottom). Red line depicts the population average³. Data are mean ± s.e.m. e, Trans-synaptic retrograde rabies tracing from AVPe^TH neurons. f, MPOA^Gal neurons presynaptic to AVPe^TH neurons in females (left, indicated by arrowheads, 21.4% Gal⁺ neurons, 47 out of 220 neurons, n = 3) and males (right, 16.7% Gal⁺, 4 out of 24 neurons, n = 2). g, Direct and indirect MPOA^Gal to PVN^OXT connectivity. Asterisk, AVPe^TH neurons form excitatory synapses with PVN^OXT neurons in females¹¹. h, Conditional monosynaptic retrograde tracing initiated from PAG. i, j, Injection sites with mCherry⁺ starter neurons in PAG of Vgat-IRES-Cre (i, left) or Vglut2-IRES-Cre (j, left) mice. Presynaptic, rabies⁺Gal⁺ neurons are detected in MPOA when tracing is initiated from PAG^Vgat (i, right, indicated by arrowheads), but not PAG^Vglut2 (j, right), neurons. Scale bars, 50 μm (a, f and i, inset), 200 μm (i and j, left) 250 μm (b, c, inset and i and j, right) and 500 μm (c, left).