SIDS is every young parent’s nightmare. Fortunately, the number of babies who die in the cradle for unknown reasons has fallen enormously in the Netherlands over the past fifty years. Yet it still happens in nearly one in ten thousand newborns. Scientists have now found a biological cause for the first time.
The researchers from California have taken the brain stems of 70 babies who died from SIDS investigated. In doing so, they found abnormalities in the serotonin receptor, officially called the 2A/C receptor. Previous research in rodents has already shown that signals from the 2A/C receptor cause arousal and ‘autoresuscitation’, which helps the brain maintain its oxygen level during sleep. It seems that babies with an abnormality in this receptor are vulnerable to SIDS under certain circumstances.
Serotonin receptor abnormality
Harvard researcher Robin Lynn Haynes docks Scientias.nl what exactly they discovered. “Our research has revealed an abnormality in the functioning of the 2A/C receptor in babies who have died of cot death. We think this anomaly is partly responsible for the deaths of these children, but it is too early to say that we have solved the mystery. We and other scientists have also found abnormalities in other neurotransmitters and serotonin receptors in babies who died from SIDS. And there are also babies in whom we could not find any abnormalities.”
It is still difficult to do research. “Unfortunately, it is not yet possible to test a live baby for biological abnormalities, so more research is needed. So for now it is important to continue to remind parents of the basic guidelines of safe sleeping for babies, so that the risk of SIDS is as small as possible. For example, it is important to put the baby on his back in bed, on a firm and flat mattress in a cradle. No bedding that is too soft, do not dress too warmly, ventilate well, do not use a duvet for the first two years and cover the bed in such a way that the baby cannot put his face under the blanket. Loose pillows or toys in the crib are out of the question, as is sleeping in the same bed as a parent, sister or brother,” explains Haynes.
Three things that come together
According to the scientists, there are three things that come together in cot death: First, the child, who is not yet 12 months old, is in a critical period with regard to the development of the heart and lungs. Second, it is exposed to an external stressor, such as sleeping on its stomach, a duvet or co-sleeping with someone else, and third, the baby has a biological abnormality that makes it vulnerable to breathing difficulties during sleep.
Age matters
But how exactly does this defect in the brain increase the risk of SIDS? “We have the the marrow is swollen studied in babies who died from SIDS and compared this brain region with that of babies who died from a known cause of death. The medulla oblongata is part of the brain stem and regulates the autonomic nervous system, including breathing. The hormone serotonin plays an important role in this. This neurotransmitter transmits signals in the brain using special proteins called receptors that are attached to the surface of nerve cells. Serotonin receptors in the medulla, such as receptor 2A/C, protect the body against breathing difficulties, especially during sleep when the baby is head down or in bed with someone else. During our study, we found abnormalities in a number of babies studied when we looked at serotonin receptor 2A/C. It seems that the abnormalities get worse after a few months, because the older babies on average had more problems with the uptake of receptor 2A/C,” says the Harvard researcher.
This has revealed a new piece of the puzzle in the search for the causes of unexplained cot death. However, much follow-up research will be needed to further understand the biological factors. “It is surprising that age plays such an important role in the extent of brain abnormalities. Because of this, it seems that there are different mechanisms at play in younger and older babies. More research is needed to better understand these mechanisms and to determine how they interact with infants’ environmental factors in general,” concludes Haynes.
2023-05-27 12:15:47
#biological #SIDS #finally
