What rat empathy might reveal about human empathy | World Weekly
Bartal expected to see this activity in rescued mice, because human empathy appears in these areas. But she was surprised that even those he did not do Rescue of cage mates showed neurological effects. “The rats are actually dealing with the fact that there’s a rat in distress — and it’s trapped, and it’s unhappy,” she says. “And they activate this empathy system, whether they help or not.”
If the same mechanism is triggered in all cases, except that behavior Between pairs within and outside the group differ, what gives? The difference appears to lie elsewhere, including in the nucleus accumbens, which handles carrot and stick-type neurotransmitters such as dopamine, serotonin and GABA. “It’s active when you eat something delicious, when you make money, or when you have sex,” Bartal says.
It’s often called the reward center in the brain, she adds, “but today, there’s a greater understanding that it’s not just an image.” A newer view of dopamine in the nucleus accumbens associates it with the expectation of reward and the motivation of its pursuit. “The main function of the brain is to get you to deal with things that are good for your survival, and to avoid things that are bad for your survival,” Bartal says.
She repeated her experiment to focus on this area using a method called fibrinometry, which allowed her team to observe neural chatter in live mice. They injected the animals accumbens with genetic material that makes neurons shine as the synapse rises. Then they implanted fiber-optic strands to observe those bursts of light while watching the mice roam. Indeed, the mice that released their roommates showed the most activity in the nucleus accumbens. Signals of this activity peaked as they approached the door to open with their snout. This told Bartal that for the rats who roamed freely, the salient moment was to free themselves, rather than to play with their friend.
Finally, Bartal tapped the rat nucleus accumbens with a dye that tracked the source of the electrical signals. She wanted to find where this impulse to help originated first. (If a hungry rat was looking for pizza on a New York subway, its gustatory cortex would move the reclining pages.) By taking brain slices from the animals shortly after they had performed a rescue mission and observing the areas where the dye reached those that overlap the c-sines that Expressing Fos, she could tell which parts of the brain were talking to each other.
Bartal traced calls to the stimulation center during rodent rescue missions and found a caller she recognized: the anterior cingulate cortex. You suspect that this indicates a line of communication between empathy and reward that could be important for understanding compassionate behavior. But she says it is still too early to “completely outline the exact circuits involved”. “That’s what we’re working on now.”
“This is a fantastic study,” Stanford neuroscientist Robert Sapolsky wrote in an email to WIRED. Sapolsky, who was not involved in the study, wrote the book Acting: Human Biology at Our Best and Worst, which describes what motivates human behavior – i.e. overall ratings of ‘us’ versus ‘them’.
The team’s findings tell us a lot about ourselves, according to Sapolsky, because experts expect identical outcomes in humans’ brains: us-discrimination, anterior cingulate making requests, and accelerating motives. Conducting such detailed brain experiments would not be acceptable in humans, and showing that this happens in mice offers a bittersweet message, he feels. The good news, Sapolsky writes, is that “the roots of our ability to help and empathize are not the products of Sunday morning sermons. They are older than our humanity, older than our selves. His legacy long predates us as a species.” The bad news is that our penchant for those around us is old, too.