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News Page 12 Street Roots • April 1 5 -2 1 ,2 0 1 6 Talking heads Larry Sherman brings to the masses a better understanding o f PTSD and how, i f left untreated, it can get into our genes BY A M A N D A WALDROUPE suffered sexual abuse or child abuse - can also STAFF W R .TER ortlanders are a little nerdy, so it’s not Larry Sherman: People hear the phrase all that surprising that Science on “PTSD” and they immediately think ‘soldier’ Tap, a science lecture series where or ‘veteran.’ It definitely is not something attendees can also enjoy a beer, regularly that is just for soldiers. It’s true that the sells o u t first indication that it is a syndrome was But Dr. Larry Sherman never expected from war. We’ve just learned so much about his talk, “The Neuroscience of Trauma: it from returning veterans. Most of the From Trigger Warnings to PTSD,” to sell research has been from veterans. out three times. I think any person who has experienced Sherm aiys a senior scientist in the trauma of any sort is prone to developing division of Neuroscience at Oregon Health PTSD. Recognizing that has been huge. So & Science University (OHSU). He delivered many people are suffering and it was his talk at Vancouver’s Kiggins Theater on unclear why they were behaving the way Veterans Day last year, and in two theaters they were after these events. They were in Portland to packed audiences. self-medicating, developing addiction issues. When he was growing up, Sherman It includes being in a car crash, surviving a noticed that his father, who served in the disease that is considered likely fatal, Navy during World War II, would startle at terminal illnesses, cancer survivors who the sound of fireworks. He was quiet, stoic, have to go through rounds of chemotherapy soft-spoken. It was only at the end of his and knowing that they may die. mother’s life that Sherman learned his 1 'was talking to a. fellow who was a father had once been talkative and effusive. counselor for several of the 9/11 workers Before he died, who helped the aid workers at the site. A ■ Sherman’s father huge proportion of those people developed told his son about PTSD. You don’t think of someone who is a his experiences in firefighter having PTSD, but what they see the war, and and go through is putting them through Sherman realized trauma on a regular basis. that his father A.W.: What is the difference between suffered from post- experiencing trauma versus having PTSD? traumatic stress disorder. Startling L.S.: Let’s say you’re in a car crash. The at fireworks wasn’t way most people will react to that is to be in l S S ! merely nervous a state of shock. You’ve just been through Larry Sherman behavior; it was a this life-threatening event We’ll be response to the trigger of a traumatic disoriented for a while, we’ll be a little memory. jumpy, maybe even avoid cars or be nervous PTSD is a mental disorder that develops about getting in a car. after a person experiences one or more That is part of a normal fear response. traumatic events - events that are life- That will only last a short time. Our brains threatening or so dangerous or frightening are capable of understanding this isn’t going that the person goes on to suffer from to happen every time we get in a car. We nightmares, anxiety, depression and suicidal separate (the car crash) from normal life. tendencies. They have intrusive thoughts “Fear extinction” is the process of basically and feelings related to the traumatic event. forgetting to be fearful, allowing you to no People can become hypervigilant in certain longer have this fear of this thing that will circumstances or avoid situations that happen. Your brain is capable of separating trigger their memories altogether. the traumatic event from normal daily life. PTSD is most associated with war That’s what normally happens. But let’s veterans, but people who have suffered say you have a very intense traumatic event, childhood abuse, sexual abuse or domestic a bus crash. You saw decapitations, fire and violence are also prone to develop the explosions, and you were trapped for some disorder. time and someone pulled you o u t It’s a Sherman, who studies the molecular and more intense set of events that happened. genetic impacts of neurodegenerative All sorts of stimuli are being turned on to conditions and diseases such as multiple the max. That can turn into PTSD. sclerosis, talked about his Science on Tap Because of the intense amount of stress lecture and research being done that shows you’re going through, your cortisol levels go PTSD can alter a person’s genes - and be up. Cortisol is a stress hormone, and passed down through generations. chronically high cortisol will impact the way your nervous system responds and forms Amanda Waldroupe: A lot o f people still memories. You will always associate getting seem to think, or assume, that the vast in a car or a bus with that accident The majority of people with PTSD are combat brain is failing to separate patterns. The veterans. B u t it’s true that many different amount of trauma, the degree and intensity groups o f people - like people who have P of the traUma can really push something from a normal traumatic stress response to PTSD. A.W.: D uring your talk, you said, “triggers o f these events may not even be associated with the event. Things are indirectly linked.” Could you give some examples? L.S.: I think the example I used is a room where there is an explosion, and there’s a yellow chair. That causes you to relive the entire experience. You’ve taken in all the details of what you experienced at the time of the trauma. For rape victims, passing by a park where the rape happened could be a triggering event. Or a certain smell, or a song that was on the radio. Even though they are not the event themselves, they’re all triggering. A.W.: In your talk, you described cortisol as a “fig h t or flig h t” hormone that is activated when we are fearful. I t’s normal to have high cortisol levels sometimes, but what are the impacts o f long-term high cortisol levels over time? L.S.: If you’re constantly reliving your trauma, which is what you do with PTSD, (cortisol levels) will stay high. Cortisol is not meant to stay high. There are many side effects - metabolic diseases, headaches, depression, anxiety. In terms of the PTSD, one thing we know that happens is that it inhibits a process in our brain called neuro genesis. A.W.: You talked about that in your lecture - that the brain has neural stem cells, which grow and develop throughout our lifetimes in a process called “neurogenesis.” B u t you said the cells o f people with PTSD might develop differently. L.S.: Most of the learning and memory involved in neurogenesis happens in the hippocampus (a region of the brain responsible for emotion, learning and memory) and it stays in the Hippocampus. One of the major functions of neurogenesis is to allow pattern separation to occur. If you have normal neurogenesis, your cortisol levels are normal. You start to learn that every time you get in a car, it doesn’t explode. But if cortisol remains high, (it) inhibits neurogenesis. That’s one of the mechanisms that maintain PTSD. You’ll always associate a car with explosions. A.W.: There’s research that suggests, because o f how neurogenesis can become inhibited, that the children o f people with PTSD can have a genetic disposition to developing PTSD. L.S.: There are people, maybe, who are more prone to PTSD. Those studies are ongoing. There have been a small number of genes that have been identified. The research is in its very early days. There is also this effect on genes when the environment triggers the methylation of DNA (methylation is a process that typically modifies the function and expression of DNA) or assimilation of histones (a type of protein). ‘Histone assimilation” is one way to regulate DNA expression. The DNA wraps around histone proteins. You’re not changing the structure of the DNA. You’re changing the chemical make up in a way that prevents the DNA from being normally expressed. Chronically high cortisol and high levels of stress change DNA methylation. The result of that is that the function of neurons and nerve cells could be See HEADS, page 13
