Elevated (+)-maze and hole-board exploration in lurcher mutant mice

The behavior of lurcher mice, a mutant with degeneration of cerebellar cells, was compared to that of normal mice for three days in two tests of exploration; an elevated (+)-maze and a 4 x 4 hole-board. In the elevated (+)-maze, lurcher mutants visited fewer closed arms than normal mice only on the first test day. Lurcher mutants were slower to emerge from the first closed arm but did not differ from normal mice for entry latencies into the first open arm. The time spent by the mutants in the open arms was higher than that of normal mice, an indication of decreased inhibition to open spaces. In the hole-board, lurcher mutants visited fewer holes than normal mice only on the first day of testing. In proportion to the total number of holes explored, lurcher mutants visited fewer center holes and fewer holes situated next to each other. These results may be due to a lesion-induced tendency to explore a more restricted region of a novel spatial environment and to explore it in a more haphazard fashion.