TACR1 and sudden infant death syndrome: Taking the above observations together, we suggest that the significantly abnormal expression of NK1R in both the IO and NTS in SIDS cases may contribute to an inability of a SIDS infant to execute appropriate motor responses in order to respond to life threatening challenges during sleep, which may underlie the pathogenesis of SIDS in conjunction with other neurotransmitter abnormalities within the same or associated medullary nuclei.