A recent study suggests that regular light-intensity exercise (LIE) may help erase fear memories and prevent post-traumatic stress disorder (PTSD). The research indicates that the brain-derived neurotrophic factor (BDNF) plays a crucial role in this process, as it enhances activity in the hippocampus, the region of the brain responsible for memory and learning. This finding could pave the way for new exercise-based treatment and prevention programs, offering hope to PTSD patients who struggle to maintain a consistent exercise routine. Post-traumatic stress disorder, Brain-derived neurotrophic factor
Erasing Fear Memories
According to the research, consistent light-intensity activity may curb traumatic memories as well — an essential part of post-traumatic stress syndrome (PTSD). In rats, a previous study employed an animal treadmill exercise model to explore the impacts of LIE on fear memories (Wu et al., 2019)
In the first experiment, rats were placed in a chamber and exposed to a conditioned stimulus (CS)—two simple tones—followed by electrical stimulation of their feet that leads to fear memories. The rats then spent the following 4 weeks completing LIE training. The fear memories of rats were subsequently tested by returning them to the same chamber and observing how quickly they would freeze –animals tend to freeze in a new environment, learning that only when it goes wrong are their imagery skills at their best. This is an important discovery, as PTSD is typically defined to a significant extent by intrusive memories and increased fear responses to traumatic events.
The Role of BDNF
To understand how fear memories are being erased by LIE, the researchers probed in greater depth into the process. One discovery they made is that the brain-derived neurotrophic factor (BDNF) is particularly involved in this. BDNF is a signaling molecule that typically increases with chronically exercised, and it performs in the hippocampus which is crucial for memory and learning.
Importantly, the exercise-induced reduction in fear memory recall was lost when researchers had previously inhibited BDNF signalling in rats. This new evidence suggests that BDNF out in front may orchestrate the way LIE impairs fear memory and counters PTSW. Animals who receive LIE have an enhanced BDNF activity and a partial restoration of hippocampal- dependent behavior that might be helpful for counteracting the behavioral consequences of PTSD.
Impact and Possible Directions for Future Work
These results can inform on how to treat and prevent the symptoms of PTSD. Depression often emerges with post-traumatic stress symptons and disrupts routine. These findings suggest that the exercise can be carried out in a very low intensity and still anti-relapse potential for PTSD.
The authors suggest that their findings could help pave the way for exercise treatments and preventions programs for PTSD patients. These programs could leverage the effects of BDNF and hippocampal neurogenesis in order to provide non-pharmacological alterations for PTSD management, allowing patients to actively engage in their recovery. As more studies come out regarding the link between exercise and physiology of brain function, and mental health consequences, works like this one offer a solution on how to help humans with PTSD.
