A mother’s tender loving care can help soothe pain in infants, and it also impacts early brain development.
New scientific research backs up the old adage that when a mom kisses a baby’s boo boo, the pain goes away. What’s more, the research also finds that maternal caregiving changes gene activity in a part of the brain that is involved in our emotions, thereby affecting an infant’s developing brain.
Senior study co-authors Regina Sullivan, Ph.D., a professor at the New York University School of Medicine and its affiliated Nathan S. Kline Institute for Psychiatric Research, and Gordon A. Barr, an associate professor at the University of Pennsylvania, presented their findings today at the Society for Neuroscience annual meeting in Washington, D.C.
The researchers analyzed tissue in rat pups’ brains from the almond-sized amygdala region, which is responsible for processing emotions like fear and pleasure.
Speaking to Healthline from the meeting, Barr said, “We looked at animals that had a mild electric shock with the mother present, and as you would expect from the literature, we found the pain behavior of the infant was reduced when the mother was present. But we also found that it affected gene expression in a structure of the brain called the amygdala … The amygdala is very important in the attachment of the mother to the infant during these early crucial periods.”
The researchers found that several hundred genes were more, or less, active in rat infants experiencing pain than in rats who were not in pain. When the mother was present, the researchers noticed that fewer genes were similarly expressed.
“The genes that were expressed seemed to be more coherently organized into clusters that had specific functions, like changes in genes that related to development of brain structure. Even though there were fewer genes, there were major changes in genes that are related to very important structures and events that have long-term effects,” said Barr.
The genes were also found to be regulated in different ways. For example, pain tended to increase the expression of many of these genes, and the mother’s presence tended to dampen the expression of the same genes.
Barr said, “I was surprised by the huge number of changes related to brain development that was changed by the presence of the mother. One thing you can imagine was that pain increased the expression of lots of genes, and then the mother brought the pain back down to normal. That’s not what happened. The mother had her own effects that were both overlapping and different from that of pain alone. That’s an important implication in the mom’s presence of not just dampening pain, but having pretty global effects that we don’t really understand.”
Sullivan told Healthline that early life experiences program our brains and change our emotional and cognitive processing.
“We know that early life adversity associated with a caregiver makes the child particularly vulnerable to later life psychiatric disorders, much more than just experiencing trauma without the caregiver. If something happens just once or twice to the child that’s painful, it’s probably great if the caregiver is there to help the child. However, repeated presentations of trauma and pain that occurs in the nursery to babies who are very sick program the brain differently,” she said.
According to Barr, about 10 to 20 painful procedures are performed in neonatal units every day, and about half of these procedures are done without any analgesics, or pain medications.
There is “a push” to have mothers present and interacting with the infant while the procedures are being performed. “The idea is to try to get environmental manipulation, including maternal presence, coddling, or other cues, such as a mother’s scent, that could relieve the pain,” said Barr.
These efforts are very effective, said Barr, adding, “But literature in animal models shows that having pain in the presence of the mother can have long-term consequences of psychiatric disorders, such as depression and anxiety. We would like to know what those consequences are.”
Barr and Sullivan believe further research is needed to study animals when they grow up, in order to find out what is changing in terms of pain circuity, pain responsiveness, and emotional and physiological responses to pain.