Because patients with PWS presented with blunted respiratory responses to hypercapnia in previous studies [21, 33] and because LC neurons enhanced CO2 sensitivity [18], we examined whether necdin deficiency recapitulated respiratory phenotypes using in vivo plethysmography at P4 (n = 8 for both WT and Ndn +m/−p mice) and P8 (n = 11 for both WT and Ndn +m/−p mice). Here, NDN is linked to Prader-Willi syndrome.