Glucose metabolism in the rat frontal cortex recovered without the recovery of choline acetyltransferase activity after lesioning of the nucleus basalis magnocellularis.

We measured the cerebral metabolic rate of glucose (CMRglc) by using positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) and the choline acetyltransferase (ChAT) activity at 3 days and 3 months after destruction of the nucleus basalis magnocellularis (NBM). Although the frontal ChAT activity remained 20% lower than that of controls even at 3 months post-lesioning, the frontal CMRglc, which was reduced by 40% at 3 days, returned to normal at 3 months, namely CMRglc recovered with time without the recovery of ChAT activity with time. Since glucose metabolism reflects mainly presynaptic neuronal activity, we speculate that presynaptic rearrangement may have some relation to the recovery of CMRglc.