Correlation between behavioral status and cerebral glucose utilization in rats following freezing lesion.

Standard small, superficial freezing lesions placed along the anterior-posterior plane of the left cortex produced behavioral changes in rats. One to 3 days following the lesion, rats showed asymmetries in somatosensory responsiveness, decreases in running wheel activity and difficulty with limb coordination. No changes in spontaneous circling were seen. At the completion of the behavioral testing on day 3 the [14C]2-deoxyglucose method confirmed the presence of widespread depression in local cerebral glucose utilization with cortical areas ipsilateral to the lesion being most affected. At this time the degree of the somatosensory deficit was significantly correlated with the extent of the depression of glucose utilization in the cortical areas of the lesioned hemisphere. At 6 days following the lesion only deficits in limb coordination remained, while local cerebral glucose utilization had returned to within normal limits. It is concluded that the demonstrated behavioral changes were a manifestation of widespread functional depression, as reflected by decreased cortical glucose utilization throughout the lesioned hemisphere.