The rats They create neurological maps of places to avoid after experiencing a threat and think about them when they display worry-related behaviorswhich can provide information on the neuroscience of common psychological disorders such as anxiety.
A team led by the University of Minnesota (USA) did an experiment with rats that were threatened when they went to look for food and analyzed their subsequent behavior when returning to the place, to examine certain parts of their brain.
The study published by Plos indicates that Specific brain cells in rats mark distant places to avoid after negative experiences, and they think about those places even after leaving.
There are many theories about the reasons for anxiety, among them that it is associated with a psychological phenomenon called approach-avoidance conflict, in which a person desires something but contrasts it with an associated negative result.
To examine the neurological basis of this phenomenon, the researchers studied rats as they headed to search for food, which was at the end of an L-shaped path.
Partially hidden in the corner of L, they placed a robot similar to a predator that, at times, charged them, moved a kind of tail and made something resembling claws, to simulate an attack.
After experiencing this situation, the rats began to perform avoidance behaviors, such as hesitating or fleeing to safety, which the researchers propose are associated with worry about the robot.
Some animals were implanted with probes to monitor the hippocampus, the part of the brain believed to be involved in learning and memory, focusing on neurons called “place cells,” which activate when an animal visits a specific location.
The researchers were able to determine, by examining the activity of these neurons, which ones were associated with the location of the food and which ones were associated with the location of the robot.
After being threatened, some rats hesitated to approach the food, and increased activity was observed in place cells associated with the location of the robot and the food.
The researchers consider that this behavior may represent an approach-avoidance conflict between wanting the food and concern for the aggressor.
When the rats turned around mid-stroke, active place cells were primarily associated with the robot’s location.
Normally, place cells are only active when the associated location is directly in front of the animal, but in rats that turned around and fled, those associated with the robot were observed to remain active.
Anxiety is related to the ability to imagine situations, something in which the hippocampus and place cells are known to be involved.
The researchers observed far fewer worry-related behaviors among the rats when they were given the anti-anxiety drug diazepam, which also altered hippocampal activity, reducing neural patterns associated with anxiety behaviors.
Worrying about the future, the authors write, “requires mental representations of imagined negative future outcomes.”
Rats confronted with the predator-like robot guarding a food source developed new mental representations of the robot’s location, causing them to transiently think about where the robot was before searching for food.