Scientists have discovered a region in the frontal cortex of the brain that might be involved in coordinating an animal’s reaction to potentially stressful circumstances. Comprehending the location, manner of regulation, and potential malfunctions of neural networks pertaining to the frontal cortex may offer valuable understanding regarding the circuits’ involvement in stress- and trauma-related psychiatric diseases in humans. Leaders of the National Institute on Alcohol Abuse and Alcoholism (NIAAA), a division of the National Institutes of Health, released the study in the journal Nature.
Senior author of the study Andrew Holmes, Ph.D., senior investigator in NIAAA’s Laboratory of Behavioural and Genomic Neuroscience, stated, “Experiencing traumatic events is often at the root of trauma-related and stress-related psychiatric conditions, including alcohol use disorder (AUD).”
Observing others go through traumatic experiences can also be a contributing factor to these disorders,” the statement goes on.
Understanding possible threats by seeing how others handle danger can be a useful strategy for avoiding harm in animal models of stress and trauma.
Predisposing factors for trauma and stress-related psychiatric disorders in humans may become clearer when we comprehend how the brain interprets direct experience of a threat versus witnessing another person’s reaction to a threat.
In order to understand how animals reduce their own risk and identify potential dangers by watching how others react to threats, scientists looked at the brain activity of mice that were going through the process of observational fear learning. A part of the brain known to be important for processing social cues and assessing danger in humans, mice, and other animals was the focus of the study: the dorsomedial prefrontal cortex (dmPFC).
Using mice that observed other mice learn to correlate a sound cue with a modest foot shock, the researchers recorded activity along neuronal circuits that lead to and from the dmPFC. Receivers of this cue-shock combination usually teach their animals to “freeze,” or stop moving, in response to auditory cues. The identical dmPFC brain circuits were subsequently used to monitor activity in the observer mice after they were given the sound cue-foot shock pairing. Upon encountering the auditory cue as a “threat,” the researchers observed that the observer mice exhibited a synchronized activation and adjustment of neural circuits that either trigger or inhibit the freezing reaction.
“Whether there are brain mechanisms that differentiate between experiencing a threat directly and witnessing someone else’s response to it remains unclear,” Dr. Holmes explains. “Yet, our research indicates that dmPFC pathways are necessary for mice to learn about threats through observation, and that dmPFC neurons’ activity patterns during observed threat experience differ from those during direct threat experience.”
Researchers believe that one of the main roles of the dmPFC in the observer mice may be to strike a compromise between the survival needs of other vital processes (such risk assessment or soothing others) and the requirement to minimize injury (i.e., freezing). The findings, they add, may potentially indicate a role for dmPFC impairments in trauma- and stress-related mental disorders in people by indicating that maladaptive reactions to socially learnt dangers may result in part from these pathways’ deficiencies.
According to NIAAA Director Dr. George F. Koob, “this study underscores the importance of basic neurobehavioral research in defining the neurocircuits that contribute to elements of post-traumatic stress, a key driver of psychiatric disorders and alcohol use disorder in particular.” “These findings could someday enhance prevention and treatment efforts for AUD and other stress/trauma related diseases by identifying patterns of brain activity that underpin how animals learn about risks from others.”
Support for this research was provided by the National Institute on Mental Health and NIAAA intramural research programs. Grants from the National Institute of Neurological Disorders and Stroke (NIAAA) and other sources contributed extra funds.
Journal Reference
National Institute of Health, Researchers identify brain hub with key role in learned response to direct and indirect threats | National Institutes of Health (NIH)
