MR images have shown regions in the brains of infants that suggest that they are more sensitive to pain than adults, according to a study by U.K. researchers published online on 21 April in eLife.
Researchers from the Oxford University Department of Pediatrics analyzed 10 healthy infants between 1 and 6 days old and 10 healthy adults between 23 and 36 years old.
MRI scans were then acquired of the babies' brains as they slept and were poked mildly on the bottom of their feet with a special retracting rod so as not to wake them. The scans were then compared with brain scans of adults exposed to the same pain stimulus.
Lead author Dr. Rebeccah Slater and colleagues found that 18 of the 20 brain regions active in adults experiencing pain were also active in babies. Scans also showed that babies' brains had the same response to a weak "poke" as adults did to stimulus four times as strong. The findings suggest that not only do babies experience pain much like adults, but that they also have a much lower pain threshold.