The development of suckling behavior of neonatal mice is regulated by birth

Abstract

BackgroundAlthough the function of the sensory system rapidly develops soon after birth in newborn pups, little is known about the mechanisms triggering this functional development of the sensory system.ResultsHere we show that the birth of pups plays an active role in the functional development of the sensory system. We first optimized the experimental procedure for suckling behavior using neonatal mouse pups. Using this procedure, we found that preterm birth selectively accelerated the development of suckling behavior in neonatal pups, but not that of motor performance, suggesting that the birth of pups regulates the functional development of the sensory system soon after birth.ConclusionsTaken together with our recent findings that birth itself regulates the initiation of sensory map formation in the somatosensory and visual systems, these results support the idea that the birth of pups actively regulates the anatomical and functional development of the sensory system.

Alteration in the time and/or mode of delivery differentially modulates early development in mice

“…The second one is focused on the effect of intrauterine exposure to mifepristone on pup's development. However, Dr. Kawasaki and his team have shown that the in utero injection of mifepristone does not affect pups' survival rate, suckling behavior, righting reflex, nor body weight [5,6], therefore suggesting that the effects observed in the mifepristone-treated group reflect changes due to a premature birth.…”

“…The fetus' brain is also prepared for this transition by slowing down its growth right before birth [3] and dampening its sensibility to pain [4]. Moreover, preclinical studies have recently defined birth as a critical period that initiates the development of brain structures such as the formation of sensory maps [5,6]. For these reasons, changing the time and/or way of being born engender deviations from the original developmental program that may lead to shortand/or long-term consequences [7].…”

Pyramidal neuron growth and increased hippocampal volume during labor and birth in autism

“…Growth during labor and birth might underlie the defects in neuronal and network wiring and affect an essential period of sensory acquisition and social interactions. Birth itself acts as a triggering signal to accelerate cortical sensory maps and major early functions including suction ( 46 , 47 ). It is suggested that the reduction of the inhibitory actions of GABA and the aberrant synchronized activity generated consequently affect this operation, leading to long-term sequelae.…”

Targeted Mutation (R100W) of the Gene Encoding NGF Leads to Deficits in the Peripheral Sensory Nervous System

“…After birth, the environment is drastically change and the newborn pups start to receive external sensory stimuli and need to interact with other littermates and mother to keep warm and obtain milk ( Weber et al, 2013 ; Toda and Kawasaki, 2014 ). The sensory nervous system deficits may affect the mother-pup and pup–pup interactions ( Toda and Kawasaki, 2014 ). During the first week of life, we also found that homozygous mice often stayed outside the nest.…”