Reproducible and persistent weakness in adult rats after surgical resection of motor cortex: evaluation with limb placement test.

OBJECT

The purpose of this study was to develop a new rat model for surgical brain injury with motor weakness and to find an adequate behavior test for the application of the model.

METHODS

Thirty rats were divided into three groups: craniectomy (n = 10), durotomy (n = 10), and corticectomy (n = 10) groups. The coordinates of the three points from the bregma (coordinate A = +4,+1, B = -2,+1, and C = +4,+6). We evaluated right limb motor performance by the modified limb placement test and the cylinder test.

CONCLUSION

Persistent motor weakness was observed for 2 months in the corticectomy group by the limb placement test, whereas the cylinder test could not detect the weakness. We established a reproducible and persistent rat brain injury model and found that the modified limb placement test is sensitive enough to evaluate residual subtle weakness in this model.