In an attempt to create a new animal ‘model’ of human depression, researchers in Japan have developed a robotic rat with the sole purpose of terrorising living rats in laboratories.
The ‘rat-bot’, called WR-3, is an attack robot that bullies rats into a state of depression. The robot is about the same size as a regular rat, has motorised wheels so that it can move and is programmed to operate in three different modes; ’chasing‘, ’continuous attack’ and ’intermittent attack‘. In chasing mode, the robot closely follows the rat at all times in order to scare the animal, in continuous attack mode, the robot aggressively knocks into the rat non-stop, and in intermittent attack mode, the robot attacks the rat for five seconds whenever it moves and then stops – both of the attack modes are designed to cause severe stress induced by psychological fear and physical pain.
The researchers set the robot to continuous attack mode and let it loose on two groups of young rats once a day for five days. It was concluded that the deepest depression was triggered by intermittent attacks on mature rats that had been constantly harassed when they were younger.
The researchers hope that they can use this new model of depression to test new drugs. But, like all other animal models of depression the measure of ‘depression’ they use is very crude (activity levels) and cannot hope to accurately predict highly complex and variable human psychological disorders.