Investigating the Role of the Nucleus of the Solitary Tract and Feeding-Related Peptides on Mammalian Suckling

Mammalian suckling is an instinctive and well-conserved social behavior. This behavior is crucial to the survival of neonates and it is one of the first fully functional behaviors in the brain. Maternal odor has been well characterized as a strong stimulus for suckling and in studies where the dam is anesthetized the mouse pups are able to successfully execute the behavior. However, it is not well known how hunger and satiety effect mammalian suckling. To investigate this question, neonatal mice at various stages of development were injected with feeding-related peptides. After injecting neonatal mice with orexin A, SB-334867, or leptin, we recorded changes in weight as well as their latching latency, the time it took for them to start suckling. In addition, we also performed righting reflex tests to determine whether any observed changes in suckling were due to effects on suckling specific regions of the brain or whether it was due to whole brain stimulation. In the scientific literature, orexin A has been shown to increase feeding in adult mammals while SB 334867 and leptin have been shown to decrease feeding. However, in the neonatal mice tested at ages P2, P7, and P13, there were no statistically significant differences in the suckling intake between the control groups and the treatment groups. For the latching latency and the righting reflex tests, there was also no statistically significant difference between the control groups and the treatment groups. This data indicates that orexin A, SB 334867 and leptin do not have an affect on the suckling behavior of P2, P7, and P13 mice