Newborn baby hiccups could be key to brain development
12 November 2019
Each time a newborn baby hiccups, it triggers a large wave of brain signals which could help the baby learn how to regulate their breathing, finds a new MyAV·¶-led study.
The study, published in Clinical Neurophysiology, was based on brain scans of newborn infants.
âThe reasons for why we hiccup are not entirely clear, but there may be a developmental reason, given that foetuses and newborn babies hiccup so frequently,â said the studyâs lead author, research associate Kimberley Whitehead (MyAV·¶ Neuroscience, Physiology & Pharmacology).
Pre-term infants are particularly prone to hiccups, as they spend an estimated 1% of their time hiccupping â roughly 15 minutes a day. Hiccups begin in the womb at just nine weeks gestational age, making them one of the earliest established patterns of activity.
The present study involved 13 newborn infants in a neonatal ward who had a bout of hiccups. The babies were pre-term and full-term, ranging from 30 to 42 weeks gestational age (equivalent), so their development could reflect whatâs typical in the last trimester of pregnancy.
Brain activity was recorded with EEG (electroencephalography) electrodes placed on the scalp, while movement sensors on the infantsâ torsos provided a linked record of when they were hiccupping.
The same researchers have previously suggested that babies kicking in the womb may be creating mental maps of their own bodies,* and say their new findings may reflect the same process for the internal body.
The researchers found that contractions of the diaphragm muscle from a hiccup evoked a pronounced response in the brainâs cortex â two large brainwaves followed by a third. As the third brainwave is similar to that evoked by a noise, a newborn babyâs brain may be able to link the âhicâ sound of the hiccup with the feel of the diaphragm muscle contraction. The researchers say that postnatal processing of multi-sensory inputs is important to develop brain connections.
âThe activity resulting from a hiccup may be helping the babyâs brain to learn how to monitor the breathing muscles so that eventually breathing can be voluntary controlled by moving the diaphragm up and down,â said the studyâs senior author, Dr Lorenzo Fabrizi (MyAV·¶ Neuroscience, Physiology & Pharmacology).
âWhen we are born, the circuits which process body sensations are not fully developed, so the establishment of such networks is a crucial developmental milestone for newborns,â he continued.
Kimberley Whitehead said: âOur findings have prompted us to wonder whether hiccups in adults, which appear to be mainly a nuisance, may in fact by a vestigial reflex, left over from infancy when it had an important function.â
The research was carried out at MyAV·¶ Neuroscience, Physiology & Pharmacology and the Elizabeth Garrett Anderson Maternity Wing at University College London Hospitals NHS Foundation Trust (MyAV·¶H), and funded by the Medical Research Council, with support from the National Institute for Health Research MyAV·¶H Biomedical Research Centre.
Links
- MyAV·¶ Neuroscience, Physiology & Pharmacology
- MyAV·¶ Biosciences
- MyAV·¶ Faculty of Life Sciences
- Media coverage
- * MyAV·¶ News: Babies kicking in the womb are creating a map of their bodies
Image
- Source: , Credit: KAI Productions
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Chris Lane
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