SHORT-RANGE HOMING IN THE HOUSE MOUSE, MUS MUSCULUS - STAGES IN THE LEARNING OF DIRECTIONS

Female house mice readily learn to retrieve their pups 50 cm from the centre of an open arena and take them to their nest outside the arena' s periphery. Experimental manipulation to reveal the spatial-orientati on constituents of this behaviour disclosed three submechanisms. Guide d orientation, the direct response to objects. Path integration, the c ontinuous monitoring of spatial displacements combined with computatio n of the locomotor vector to the starting point of the path. Landmark navigation, the movement by means of distal visual cues toward a goal not directly perceived. Learning to home passes through three stages. First, the exploring mouse is directly guided to objects of interest. Second, the homing mouse adds path integration; that is, it keeps a ru nning, integrated spatial record derived from locomotion. Finally (cir cumstances permitting) the homing mouse links path integration with sp atial references to distal visual landmarks. Sparse comparative eviden ce from other species of rodents suggests that such a system of short- range topographical orientation is universal among rodents.