The Hebb-Williams test to assess recovery of learning after limbic lesions in mice.

A scaled-down Hebb-Williams closed-field maze was constructed and adapted for use with mice. In a first experiment, the acquisition performance of the original 12 Hebb-Williams mazes by BALB/c mice was studied in order to re-group the mazes into 3 main groups of difficulty (low, moderate and high). In a second experiment different problems from each class of difficulty were presented at 3 times intervals (between 3 and 7 weeks after surgery) to mice with lesions of the cingulate cortex. The rate of acquisition in lesioned mice was observed to be facilitated between 3 and 5 weeks after surgery for the most difficult mazes. This effect was reversed (impairment) at 7 weeks post-lesion. The observed biphasic behavioral modifications constitute evidence that our present protocol provides a useful tool to evaluate the time-course of changes in learning performance following brain injury.