Adams JN, et al. - Researchers measured associations between tau and glucose metabolism in cognitively normal older adults via using [¹⁸F] AV-1451, [¹⁸F] Fluorodeoxyglucose, and [¹¹C] Pittsburgh Compound-B (PiB) PET. Medial temporal lobe tau was noted to be associated with widespread hypometabolism, while tau outside of the medial temporal lobe was associated with decreased and increased glucose metabolism in PiB+ subjects. Regions with earlier tau spread were also associated with stronger negative correlations with glucose metabolism. Findings thereby suggest that low levels of tau are associated with a phase of increased metabolism, while high levels of tau in the presence of amyloid-β are associated with hypometabolism at downstream sites in normal aging.