Alongside these blunted effects on ventilation and on the sympathetic activity produced by a HF diet and the absence of effects of CSN resection in these animals, leptin was unable to modify the increase in basal CSN electrophysiological activity induced by 3 weeks of HF diet in rats [22], while in control rats and mice, leptin augmented basal CSN chemoreceptor activity [22,64,83]. The gene discussed is LEP; the disease is hydrops fetalis.