When scared or threatened, mammals can
respond in different ways. They can freeze, fight or run away. Now scientists have been studying mice to identify the brain regions involved in
this split-second decision. They showed the mice a looming overhead threat. The mice responded in the typical ways either: by freezing seeking shelter or aggressively rattling their tails. The scientists monitored the mices’ brain
activity during the experiment to find the pathways involved in the different responses. They found that mice who had been scared before were more likely to respond aggressively. This reinforcement of aggressive behaviour is a survival
mechanism but it could malfunction. In humans, exploring this mechanism could
help researchers understand conditions like PTSD and phobias.