[Three simple maze tests employing mice housed in maze apparatuses]

This report deals with three different maze methods using spontaneous learning behavior. Forty-eight mice housed in an apparatus with a multiple maze mastered the maze task on the 5th day after the start of housing. Then they were divided into four groups, and two of the groups were treated with AF64A (3.5 nmol, i.c.v.) or trimethyltin (TMT, 3 mg/kg, p.o.), and the other two groups were treated with the vehicle as the respective control. Seven days after the treatment, their memory retrieval was tested. Subsequently, the same mice were housed in the apparatus with a T-maze. After the finish of the experiment using the T-maze, they were housed in the apparatus with an eight arm radial maze. The control groups mastered the T-maze task with a 3-sec delay on the 4th day after the start of housing and the radial maze task on the 10th day after the start of housing. Both the treatments lowered the performance in all maze tasks. These results show that the mice housed in the apparatus with maze learned to negotiate the maze spontaneously, and the apparatuses are useful for estimating memory in mice with little effort.