When surprisingly violent crimes are committed, most recently including the massacre that occurred at Sandy Hook Elementary school in Newtown Connecticut, it’s the prerogative of scientists and the rest of us alike, to try to make sense of the incomprehensible. Unfortunately, most incidents such as this don’t have easy, or satisfying, answers, that can be wrapped up in a pretty little bow. What we CAN do, is try to identify certain underlying problems to prevent this sort of thing from happening again.
On that note, it’s no secret that the behavior of adults that exhibit violent tendencies can sometimes be traced back to childhood trauma, but thus far, finding an undeniable direct link between the trauma and neurological changes in the orbitofrontal cortex of the brain, which is the cognitive region in the frontal lobe that controls decision making — has been unsuccessful.. until now, that is.
In the January 15th edition of Translational Psychiatry, a team of researchers, including Professor Carmen Sandi from the Brain Mind Institute, have outlined their newest study, which highlights a direct correlation between psychological trauma in pre-adolecent rats, who have been found to undergo neurological changes similar to those also noted in violent humans including changes in brain activity, hormone levels and gene expression
According to Sandy, who is the Director of the Brain Mind Institute in addition to being the head of EPFL’s Laboratory of Behavioral Genetics, , and a member of the National Centers for Competence in Research SYNAPSY. “This research shows that people exposed to trauma in childhood don’t only suffer psychologically, but their brain also gets altered. This adds an additional dimension to the consequences of abuse, and obviously has scientific, therapeutic and social implications.”
In order to study these biological foundations, the rats involved were exposed to psychologically stressful stimuli when still peripubertal. Some of those stresses included long periods of fear, where some were stranded on a brightly lit platform; others were exposed to the scent of a fox. Upon inspection after said rats reached adulthood, they were discovered to be particularly aggressive compared to their counterparts, some even experienced a higher level of stress hormones and later puberty. In addition to depression, anxiety, lower sociability and a reduced interest in food. All of which, have been witnessed in humans as well.
They also discovered something extraordinary. “In a challenging social situation, the orbitofrontal cortex of a healthy individual is activated in order to inhibit aggressive impulses and to maintain normal interactions,” explains Sandi. “But in the rats we studied, we noticed that there was very little activation of the orbitofrontal cortex. This, in turn, reduces their ability to moderate their negative impulses. This reduced activation is accompanied by the overactivation of the amygdala, a region of the brain that’s involved in emotional reactions.” Other researchers who have studied the brains of violent human individuals have observed the same deficit in orbitofrontal activation and the same corresponding reduced inhibition of aggressive impulses. “It’s remarkable; we didn’t expect to find this level of similarity,” says Sandi.
Furthermore, they also analyzed the brains of the inflicted rats to measure certain changes in genes of their brains. Most importantly, they wanted to pay close attention to certain genes that are known to play a certain role in those that exhibit aggressive behavior. Some of which, have genetic variants that actually predispose carriers to certain behaviors. In this case, they were interested in seeing if the psychological stresses put on the rats in the study modified anything in the expression of polymorphisms. Indeed they did. “We found that the level of MAOA gene expression increased in the pre-frontal cortex,” says Sandi, which basically reaffirmed their initial hypothesis.. traumatic experiences the rats had in fact did modify the expression of the genetic variants observed.
Lastly and most importantly, the rats were then exposed to an NAIA gene inhibitor to see if it were possible to reverse some of trauma . They found that in this case, an anti-depressant, could very have a significant impact on the aggression witnessed in adults that were subjected to child-hood trauma, which could revolutionize our methods of treating such inflictions.
“This is a key finding which highlights the importance of not only developing social programs and politics, but also of reinforcing research that could offer valid [medical] treatments for individuals that have been victimized early in life,” says Sandi “We need to understand the neurobiological mechanisms to offer better solutions to break ‘the cycle of violence.’”
For Further Reading:
“Childhood Trauma Leaves Its Mark On the Brain:”
“Childhood Trauma Leaves Legacy of Brain Changes:”
By Jaime Trosper
Childhood Trauma Leaves Its Mark On the Brain by http://myscienceacademy.org is licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License.
Based on a work at http://myscienceacademy.org.