Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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Dissociating the Recovery of Reaching Success From Compensatory Changes in Skilled Forelimb Movements, After Dorsal Column Lesions in Rats. John E. McKenna and Ian Q. Whishaw, Department of Psychology and Neuroscience, University of Lethbridge, Alberta, Canada, T1K 3M4. The dorsal columns (DC) convey primary afferent input to the rat ventrobasal thalamus and sensorimotor cortex. It is well known that damage to the DC results in impairments in limb use in primates, but the effects of lesions in rodents are not well documented. In the present study, female Long-Evans rats were trained to reach for food pellets with a forelimb and then received ipsilateral DC lesions at the C2 level. Reaching success recovered within a few days of DC injury. Nevertheless, a detailed analysis of high-speed videorecordings revealed that rotatory movements (aiming, pronation, supination, etc.) were irreversably impaired. Compensation was achieved with whole body and alternate limb movements. These results indicate that: (1) sensory input conveyed by the DC contributes to rats' performance of dexterous tasks; (2) other sensorimotor pathways support successful reaching in the absence of the DC; and, (3) detailed behavioral analyses are necessary to describe the effects of injury and enable behavioral compensation to be differentiated from functional recovery. Supported by the Alberta Heritage Fund for Medical Research.

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Presentation Number SAmckenna0705
Keywords: dorsal column, lesion, forelimb, skilled movement, reaching