The hippocampus - the part of the brain that deals with learning and memory - had on average 15 per cent more neurons in the "enriched" mice than those brought up in dull surroundings. They also performed better in tasks such as escaping a water-filled maze.
The group of 12 "standard" mice were brought up with four sharing a single bare cage. The other 12 were put in a specially designed cage with a square metre of ground area equipped with paper tubes, nesting material, a adjustable set of plastic tubes, a sisal tunnel with various openings and a running wheel.
As well as their normal food, the mice in the luxury cage were given extra treats including cheese, crackers, apples, popcorn, and whole-grain nibble bars. Charles ArthurReuse content