A new study has found that the brain system enabling us to inhibit our own pain changes with age, and that gender-based differences in those changes may lead females to be more sensitive to moderate pain than males as older adults.
Researchers used fMRI scans to examine brain responses in men and women who had rated the intensity and unpleasantness of pain during exposure to increasing levels of heat. The results suggested that established gender differences in pain perception could likely be traced at least in part to this brain network, and offered new evidence that those gender differences may become more disparate with age.
The study was published recently in The Journal of Pain.
In this study, the researchers specified that they holistically examined gender-based differences that may relate not just to biological sex, but also to social factors that influence how people respond to pain.
The imaging component of the study zeroed in on the descending pain modulatory system (DPMS), a hub of brain regions that communicate with each other to engage signal transmission – including activation of opioid receptors – that enables us to reduce our own pain.
The study sample included 27 females and 32 males between ages 30 and 86 who were asked to report when applied heat reached levels of just-noticeable, weak and moderate pain and to rate how unpleasant each level felt. Researchers used the fMRI imaging to observe DPMS activity that corresponded with each participant’s individual pain response.
Results showed that a few regions within the brain’s pain modulatory system did indicate a gender-by-age difference: At the moderate pain level, men showed an increased DPMS response with older age, while as women aged, the DPMS response decreased. A decreased response in the brain is presumed to translate into a lower ability to harness our own physiological functions to reduce our pain.
Presumed is a key word: While the DPMS is believed to have a significant role in pain sensitivity and tolerance, researchers are still working toward describing exactly how it works and how an intact versus dysfunctional system shows up in scans.