A new study, published in the journal Nature Neuroscience, sheds light on what really happens in the brain during the recovery and expression of fear memories. The reaction of fear to traumatic or threatening situations helps us to avoid or escape the danger. At the same time, this fear reaction causes its learning (a fear-raising formation) in the form of a link between the stimulus and the presence of a stressor (eg natural hazard).
“This connection is very strong and forms a trace of memory that remains for years after experience, creating profound structural and functional changes in the brain that can potentially evolve into post-traumatic stress and other anxiety-related disorders,” the study researchers.
The formation of the memory of fear and its recovery is characterized by a terrible behavioral pattern associated with a series of unique physiological correlations, such as sweating, trembling and increased heart rate. Previous studies have identified multiple areas of the brain involved in the associative learning of fear, including dorsal cortex (dmPFC) and basal lateral tonsillar (BLA), which are seen as two critical structures for learning and expressing fear .
In order for the researchers to understand what is happening in the brain during the recovery of a fear reminiscence, they have focused their attention on the study of nerve processes related to “freezing” behavior, the moment when our bodies are in a threatening or terrifying state ” freezes “.
To achieve this, they combined electrophysiological activities of local and unified neural groups as well as data collected from the visual manipulation of dmPFC and BLA networks in mice.
“Our study shows for the first time that the freezing behavior is closely related to a cerebral brain condition that is manifested dynamically in the dmPFC and BLA networks with a 4 Hz oscillation,” the researchers said. “This brain condition allows the synchronous activation of individual neurons believed to be involved in information flow processes and synaptic plasticity.”
“Using the data we collected, we found that prefrontal cortical neuron activation preceded basal tarsal neurons with each 4 Hz oscillation cycle, indicating the role of the prefrontal cortex in controlling the recovery and expression of fear memories.” researchers in their study. “The use of visual manipulation showed that oscillations in the dmPFC network were sufficient to promote” freezing “behavior and resulted in a long-term memory of fear.”