How repetitive eye movements can suppress trauma

Neuroscientists have uncovered the neural basis behind a treatment for post-traumatic stress disorder.

One way to treat post-traumatic stress disorder is to present visual stimuli to a patient that stimulate repetitive eye movements while getting them to recall a trauma. This treatment can result in long-lasting healing in some cases, but no-one knew how it worked.

Now, by using optogenetics to investigate the effect of the therapy in the brains of traumatized rats, a team led by researchers at the Institute for Basic Science in South Korea has discovered the neural pathway behind the treatment.

Rats that received the treatment exhibited enhanced activity between two brain regions: the superior colliculus (a brain region associated with eye movement and attention) and the mediodorsal thalamus (a brain area connected to the superior colliculus). The mediodorsal thalamus in turn communicates with the basolateral amygdala, a brain area that controls fear expression and stores fear memory.

Nature 566, 339–343 (2019). doi: 10.1038/s41586-019-0931-y