Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

Unilateral lesions of the forelimb sensorimotor cortex (FLsmc) of adult rats result in dendritic growth and synaptogenesis in the motor cortex opposite the lesions. It has previously been hypothesized that these structural changes result from an interaction between lesion-induced degeneration and forelimb behavioral changes. Two studies are presented which examine effects of behavioral experience on lesion-induced neural plasticity. The first study independently manipulated degeneration in the motor cortex, via corpus callosum transections, and forelimb behavioral asymmetries, via restriction of a single forelimb. In rats forced to rely on one forelimb, callosal transections resulted in increased dendritic arborization in the motor cortex opposite the forced-use limb in comparison to animals that had transections alone or forced-use alone. These data suggest that mild degeneration may facilitate neuronal growth when accompanied by appropriate behavioral demand. A second study assessed cerebellar structural changes in rats given unilateral FLsmc lesions, with and without post-injury training on a complex motor skills task. Lesion rats receiving skills training showed increases in Purkinje neuron cell body size and tissue volume per neuron ipsilateral but not contralateral to the lesion. In contrast, skills training resulted in bilateral increases in sham rats relative to sham motor controls. Together, these findings further support an interaction between experience induced and lesion induced neural plasticity and that this interaction extends to remote (to the lesion) brain areas.

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Presentation Number SAbury0827
Keywords: forelimb, recovery, motor cortex, cerebellum, lesions