Feb 05 2010
What does SIDS (sudden infant death syndrome) have to do with serotonin? In new research the neurotransmitter has been identified as a possible culprit in the deadly disorder.
Neurotransmitters, for those unfamiliar, transmit messages across the junctions (synapses) between neurons. There are a number of different neurotransmitters, and these can act on some areas of the brain more than others.
In the study, Low production of serotonin in the brainstem a likely cause for SIDS, it was determined that low serotonin activity may play a role. Yes, it does certainly seem that this neurotransmitter is all the rage lately, being implicated in depression, social phobia, generalized anxiety disorder, panic disorder, irritable bowel syndrome, and poor fashion sense (just kidding about that last one). Yet serotonin is truly a work-horse molecule, and each person’s brain is different.
One thing being clarified lately is that there is more to serotonin than simple levels. The chemical doesn’t appear out of nowhere and then do its work on nothing. Essential parts of the equation to recognize are the synaptic vesicles that collect/store/release the neurotransmitter on the “sending side” of the synapse, and the receptors, which work on the receiving side of the nerve junction to complete the signal transmission.
In fact, it is thought that SSRIs (selective serotonin reuptake inhibitors — they keep more of the stuff circulating in the synapses) may take time to work because it is not just the level of serotonin the the synapses that is important, but the quantity and activity of vesicles and receptors as well. Research suggests that when exposed to increased levels of serotonin, neuronal growth/changes occur that likely results in a greater number of receptors.
All individuals, besides having different levels of circulating serotonin, likely have differing amounts of serotonin vesicles and receptors in different parts of their brain. Thus the possibility that one SSRI-level-influencing drug, such as Zoloft, can treat a number of disorders.
And now we get to SIDS. For years the cause of this tragic phenomenon has been a mystery. What causes some infant to die suddenly during sleep? Low birth weight, second-hand smoke, parents placing infants on their stomachs’ to sleep…?
SIDS has puzzled doctors and families for decades, but once the medical community recognized that a baby’s position while sleeping affects the risk for SIDS, national awareness campaigns sprouted to persuade parents to place babies to sleep on their backs. However, such campaigns haven’t completely solved the problem, prompting ongoing research to find a biological component to SIDS. [bold mine]
And that biological component could be the creation, transmission, and reception of serotonin. In the brainstem, which is the area of the brain that controls sleep. A promising lead -
[R]esearchers at Children’s Hospital Boston have linked sudden infant death syndrome (SIDS) with low production of serotonin in the brainstem, based on a comparison of brainstem samples from infants dying of SIDS compared to brainstems of infants dying from other, known causes. [bold mine]
Of course, the above research is suggestive and not definitive. (The headline writer gets half a nod for including likely before cause.) But it’s certainly something. Progress. Even if it proves to be a dead-end, at least another avenue has been explored.