Fig. 1.

RP3V kisspeptin neurons are part of a motivational circuit triggered by male olfactory cues. a Removal of the vomeronasal organ (VNOx) but not ablation of the main olfactory epithelium by intranasal infusion of a zinc sulfate solution (ZnSO₄) with the vomeronasal organ intact (VNOi) disrupted male odor-induced activation of RP3V kisspeptin neurons as determined by the percentage of Fos/Kp co-labeled cells. ***P ≤ 0.001; Dunn’s multiple comparison test; n = 28/9/7/8/9. b Kisspeptin knockout (Kiss^−/−) female mice do not show a male-directed preference, whereas female control littermates displayed a preference for the male. Strikingly, a single peripheral injection with kisspeptin (Kp-10) at a dose of 0.52 µg kg⁻¹ induced a very strong preference for the male in Kiss^−/− female mice. **P ≤ 0.01; ***P ≤ 0.001; one-sample t test (H0: mean equals 0); n = 9 per group. c Stereotaxic injection with an AAV encoding a Cre-dependent caspase bilaterally into the RP3V led to a ~70% decrease in the number of RP3V kisspeptin (Kp) cells in Cre⁺ compared to Cre⁻ females. ***P ≤ 0.001; unpaired t test; n = 7. d Photomicrographs showing viral ablation of RP3V kisspeptin neurons in KissIC mice (left: Cre⁻; right Cre⁺). e Viral ablation of RP3V kisspeptin cells disrupted male-directed preferences in KissIC mice (Cre⁺), whereas a peripheral injection with Kp-10 induced a male-directed preference. *P ≤ 0.05; ***P ≤ 0.001; one-sample t test (H0: mean equals 0); **P ≤ 0.01; Tukey’s multiple comparison test; n = 7 per group. Scale bar represents 100 µm. Bars represent the mean ± SEM. For all experimental details, see supplementary Table 1