Northeastern Research May Lead to New PTSD Treatments

Northeastern researchers found gender differences in how rats react to fear.

fear photo

Fear photo via Shutterstock

Fight or flight? Flee or freeze? You might think that kind of split-second decision making depends upon the individual. Northeastern research, however, found distinct patterns in how male versus female rats respond to fear, suggesting that the underlying reason may relate to gender.

“It was definitely something that we stumbled across. Normally, the way you measure fear in a rat in this particular kind of experiment is by freezing, only. So, if it’s not freezing then you think it’s not afraid,” says Rebecca Shansky, a psychology professor at Northeastern and one of the study’s researchers.

In this experiment, though, researchers found that a tone sounding during fear conditioning made female rats, in particular, dart when they were afraid, instead of freezing. “We found out that it was happening almost exclusively in the females and not in the males,” Shansky says.

Researchers began to distinguish between the darters and the freezers, labeling the latter passive responders and the former active responders. What they found next was compelling: The (predominantly female) rats who first darted were more adaptive to fear, and more resilient as the experiment continued. They showed less of a response, and ended up not darting or freezing later in the experiment.

The application of this discovery could be significant. If researchers can understand the neurobiological process of what makes one animal more adaptive to fear than another, they could potentially translate that into better treatments for fear-related conditions, like PTSD, in humans.

“If we can try and understand what sort of biology underlies what turns an animal into a darter versus a freezer,” Shansky says, “then maybe we can start to develop new treatments that will activate that particular set of neural circuits and help people adapt to trauma when they are exposed to it.”

Considering that women are at a higher risk of developing PTSD than men, understanding the biology behind fear could be very helpful in developing treatments. While researchers are still a long way off from using these findings to directly treat PTSD, Shansky says, “it is a promising new avenue.”