In a strange, natural phenomenon, humans are able to experience empathy for the pain of other humans. But could mice be capable of this as well?
This brain activity occurs in the somatosensory cortex, the insula (INS), and the anterior cingulate cortex (ACC) – the same regions that are associated with pain itself. Often, we’ll associate phenomena such as this to an ability that is unique in humans, given its complexity. But researcher Monique Smith and her colleagues set out to determine whether or not this same trait occurs in mice.
The research team had previously shown that “bystander” mice kept with other mice undergoing withdrawal from opioids or alcohol experienced hyperalgesia – which is a heightened sensitivity to pain – similar to the induced-withdrawal mice. Now they wanted to determine whether or not this social transfer of pain was resulting in the same brain region as it was in humans.
In their study, they compared the brain activity of “primary” mice with access to increasing concentrations of ethanol to that of “bystander” mice housed in the same room.
They found that primary mice exhibited increased activity in the dorsal medial hypothalamus once their access to alcohol was cut off. This is likely indicative of this region’s role in alcohol withdrawal. At the same time, bystander mice showed increased activity in the ACC and INS. Furthermore, they found that hyperalgesia could be reversed in both primary and bystander mice by inhibiting activity in the ACC.
Ultimately, these findings point to a potential neural overlap between physically-induced and socially-transferred hyperalgesia, increasing our understanding of both pain and empathy for pain in mice – and possibly humans as well.
By Connor Ertz, Earth.com Staff Writer
Source: Society for Neuroscience