Fear and phobias get locked into the brain’s prefrontal cortex, according to new research.
The inherent fear response has been, and still is, an integral aspect of human evolution. Primitive humans needed fear for their survival. As a result of fear, humans adapted their environment to their advantage and evolved into an advanced and capable species. For instance, the fear of darkness, cold, death, and predators are a just a few that could be associated with humanity’s need for fire, which has been a driving force for civilizations for thousands of years. However, while fear can be beneficial, it can also be crippling, especially when it induces trauma and develops into phobias.
Fear is an emotional and biochemical stress response to perceived physical, psychological or social threats. On the other hand, a phobia is an extreme fear response to perceived physical, psychological or social threats. Usually, a phobia leaves a deep, scarring, and lasting impression, which results in trigger responses where even the mention of the source of an individual’s phobia could lead to an intense stress reaction.
Phobias affect people so deeply that they are likely to cause trauma imprints or memories in which a person can easily relive all five senses associated with a particular experience. In most cases, the affected individual is unable to lead a normal life, especially in situations where they encounter their triggers. For instance, a person with a social phobia is almost incapable of leading a productive social life.
Over the years, much has been researched and is known concerning fears and the effects one’s fear has on their daily lives. However, until recently, little was known about where these fears “live” in the brain. That means that it was almost impossible to use a targeted medication in the treatment of phobias. Instead, the most effective treatment was through psychological counseling.
Now, researchers at the University of California have answered the age-old mystery of how fear affects the brain and where it stores ‘scary’ memories, which will hopefully lead to new methods of treatment including the use of medication to manage phobias. The researchers used mice whose neural system was engineered to easily respond to and identify fear responses. Additionally, viruses were engineered to easily sever neural connections, especially those associated with memory retention and consolidation.
The team then used electric shocks to generate a fear response and trigger trauma in the mice. A month later, when the mice returned to the place where they were shocked, they froze in response to the traumatic event (electric shock). Analysis of the brains of the mice showed increased activity specifically in the prefrontal cortex. The prefrontal cortex is believed to have been the last region of the brain to evolve and constitutes about 30% of the cerebral cortex. It is associated with speech and language, emotional and personality regulation, attention and memory, and executive functioning that includes tasks such as rational decision-making, planning and execution.
When the nervous system’s connection to the prefrontal cortex was severed in the mice, they could not recall the traumatic event (electric shock) and formed new connections and memories. Therefore, it was concluded that the memories associated with trauma and phobias “live” in the prefrontal cortex and this is the region of the brain that should be targeted with treatment.