Measurements of regional glucose metabolism in studies of motor control.

We used the incorporation of tracer quantities of radiolabeled glucose analogues into muscle and CNS tissues to determine, first, whether unilateral dorsal root deafferentation affects hindlimb flexor and extensor muscles of that side equally. For this we compared the incorporation of [3H]fluorodeoxyglucose into selected muscles in the intact and the deafferented side. The muscles were dissected out after exercise on a treadmill, and tracer incorporation was measured by scintillation counting. Second, we used the [14C]2-DG radioautographic method of Sokoloff to seek confirmation of the involvement of certain CNS structures in locomotor control. We found fascinating side to side asymmetries in glucose metabolism, in the cervical spinal cord, motor cortex, and caudate nucleus. There is still debate about the manner in which "neuronal function", regional blood flow, and glucose metabolism, may be coupled (or even on the existence of such coupling). However, these methods can be useful by their anatomical resolution, and the possibility of making multiple regional measurements from a single subject.