From the time we are born into this world our body is in survival mode. This innate instinct is in constant operation. There is no off switch. Our very survival depends on it. Most of the time it goes unnoticed, relegated to the deeper areas of our nervous, circulatory, and endocrine systems. It’s as though this “behind the scenes” mechanism is guiding us from any hidden dangers so we can freely go about engaging in our lives.
But as life progresses with each additional day, week, and month, this survival network not only works from a moment-to-moment basis but is now required to address events that may have taken place in the past. This system has a memory complete with emotions capable of learning. But instead of making the necessary adjustments to balance the body’s vital systems based on a “real time” measurement. It makes the same changes but from a script of the past, determined by the feelings and emotions that were collected and remembered in certain brain pathways.
Now instead of the brain/mind instructing the body how to feel. It’s the body remembering and instructing the brain how to react. So, the trauma is moving in the opposite direction through the memory it created from the past.
The underlying principle responsible for keeping us in a healthy state of balance is referred to as homeostasis. It represents the unconscious, regulatory system that establishes and maintains our optimal “default-mode” setting.
Homeostasis is the reason why we perspire when we are hot, get goose bumps when we are cold, hearts elevate when we are scared, form a scab when we are cut, keeps our hearts beating and blood pumping and why our good gut bacteria is always trying to repopulate to establish proper absorption to maintain digestive health.
Homeostasis is established through the efforts of the autonomic nervous system which directs the body to increase or decrease production of certain chemicals within these bodily systems that are designed to alert, defend, protect and ensure our survival. So, as we grow these networks continue to do their jobs without a care in the world. Regulating these vital systems seamlessly.
But what happens when we are exposed to a stressful event or series of events when we are young? How does this trauma impact the ability of this finely tuned survival mechanism?
Can exposure to early childhood adversity be a cause of cellular changes in the brain circuitry? If so, can it be seen?
For years we have known that childhood adversity and stress can trigger disruptions in neural pathways that can affect high risk behaviors, depression, addiction and other mental health disorders.
Now, in a recent article published in Nature Communications, a new brain connection was discovered by researchers at the University of California, Irvine that explains how early life stress disrupts the reward circuitry in the brain. The findings lay the groundwork to other correlations of mental health concerns.
Dr. Tallie Z. Baram, senior author and UCI Professor and Distinguished Professor in the Departments of Anatomy & Neurobiology, Pediatrics, Neurology and Physiology & Biophysics, Donald Bren and Matt Birnie, lead author and a postdoctoral researcher, formed the research team that made the discovery into how stress impacts the brain.
Dr. Baram said, “We know that early-life stress impacts the brain, but until now, we didn’t know how, our team focused on identifying potentially stress-sensitive brain pathways. We discovered a new pathway within the reward circuit that expresses a molecule called corticotropin-releasing hormone that controls our responses to stress. We found that adverse experiences cause this brain pathway to be overactive.”
“These changes to the pathway disrupt reward behaviors, reducing pleasure and motivation for fun, food and sex cues in mice. In humans, such behavioral changes, called” anhedonia”, are associated with emotional disorders. Importantly, we discovered when we silence this pathway using modern technology, we restore the normal brain reward behaviors.”
The study involved two groups of male and female mice. One group was subject to more adverse settings of limited bedding and nesting. While the other group was raised in typical cages. They found now as adult mice, the early life stressed male mice showed no interest in sex cues or sweet foods, unlike the typically raised mice. While the adversity raised female mice in contrast, did show cravings for sweet, rich flavored foods.
Interestingly, inhibiting the reward neural pathways of the male mice showed a return to normalcy, but had no effect on the female mice.
The brain mapping used to view which connections were affected revealed the nucleus accumbens (the pleasure and motivation center) and newly discovered activity in the basolateral amygdala region. They found that when this new region was stimulated, it suppressed various reward behaviors in the male mice.
“We believe that our findings provide breakthrough insights into the impact of early-life adversity on brain development and specifically on control of reward behaviors that underlie many emotional disorders. Our discovery of the previously unknown circuit function of the basolateral amygdala-nucleus accumbens brain pathway deepens our understanding on this complex mechanism and identifies a significant new therapeutic target” said Dr. Baram. “Future studies are needed to increase our understanding of the different and sex-specific effects of early-life adversity on behavior.”
The body and mind are joined together by experiences we have endured in our lifetime. They are complete with emotions and feelings that enter brain pathways and are retained to create our memories. They reside both in our mind and our body which can affect our mental state of health, when not addressed. The stress of an unresolved event makes an imprint on the neural networks that are responsible for maintaining homeostasis. This innate survival network stays on high alert long after the event(s) have passed. Draining our energy reserves and depleting our ability to fully engage in our lives.
But, through findings from studies such as this one gives us hope for breakthrough therapies and strategies for dealing with and resolving trauma. With greater understanding comes deeper healing.
-A Balanced Brain is a Better Brain for a Happier Life-