PTSD Preventable in Mice, Study Reports
Post traumatic stress disorder (PTSD) is a mental illness that usually develops after experiencing traumatic events. PTSD is one of the most commonly diagnosed conditions in military personnel, which could severely affect their ability to return to life after wartime. PTSD is characterized by episodes of fear, anxiety and other emotions associated with the particular traumatic event that affects the victim in the forms of nightmares and flashbacks. Although PTSD can be treated to some extent, the condition is still hard to treat because not much is known about PTSD and its manifestation. A new study, however, reported that a new drug could potentially prevent some of the symptoms of PTSD from developing.
The study with lead author, Kerry Ressler a professor from Emory University, used mouse models in their attempt to better understand PTSD. The team conditioned mice to be fearful of a particular sound by shocking the mice while the sound played. The researchers administered the new drug to some of the mice. After the researchers noted that the mice developed the fear of the noise, they played the noise without administering a shock to observe how the mice reacted. They discovered that the mice that were not given the drug froze in place, indicating that they were scared at the moment. The mice that received the injection of the new drug were less fearful.
"This drug binds to that receptor, by doing that, it decreases the fear memory in the mice," explained lead researcher Raul Andero reported by U.S. News and World Report. The receptor mentioned is known as the Oprl1 receptor that has been tied to easing anxiety when activated. The research team identified this receptor in an earlier part of the study where they taped mouse to wooden board for two hours in order to induce PTSD symptoms. After this experiment, the researchers studied the brains of mice from both experimental and control groups, and pinpointed the Oprl1 gene that is responsible for creating the receptor for the brain chemical, nociception.
The researchers noted that the drug was able to activate this receptor regardless of whether it was injected in the brain or abdomen. The drug was also effective when it was injected before or within 48 hours of the event. The researchers acknowledged the fact that creating a fearful event in mice might not be equivalent to the fear PTSD victims feel. However, the researchers are optimistic that the same results could be found in humans.
"We need to replicate the effect in larger animals, have safety trials and efficacy trials in humans. There's a long way from [identifying] the mechanism for PTSD and having a drug ready for humans," Ressler said.
The findings were published in Science Translational Medicine.