Mad Science 2006 : Deliberate brain damage to rats slows
A team of scientists at The Brain Repair Group at Cardiff University investigated various brain functions in rats, based on previous test studies and observations in monkeys and in humans.
Twenty-seven adult male rats were trained to press a lever in order to obtain a food reward. During this training period, their access to food was so severely restricted that the animals lost 10 per cent of their bodyweight. The second part of their ‘training’ involved forced swimming in a water maze, where an escape platform was provided but was hidden from their view.
After the training period, all the rats were anaesthetised and divided into three groups. Ten rats were injected with a toxic chemical to destroy a particular area of the brain. Another ten received the same injection but to a different part of the brain. The remaining seven rats served as a ‘control’ and received an injection of saline into the brain - an invasive and painful experience, nonetheless. Two weeks after the surgery, the animals were subjected to an intensive re-testing regi- men. The researchers noted that all of the rats whose brains had been damaged with the toxic chemical still coped quite well with pressing levers, but did poorly in the water maze.
The researchers concluded that there was a need for more such animal experiments to study brain damage.
This study was funded by the government’s Medical Research Council.
Ref. Sloan HL, Good M, Dunnett SB. Behavioural Brain Research 2006; 171:116-126. ‘Double dissociation between hippocampal and prefrontal lesions on an operant delayed matching task and a water maze reference memory task.’