Altered linear coupling between stimulus-evoked blood flow and oxygen metabolism in the aging human brain

Monroe P. Turner, Yuguang Zhao, Dema Abdelkarim, Peiying Liu, Jeffrey S Spence, Joanna L. Hutchison, Dinesh K. Sivakolundu, Binu P Thomas, Nicholas A. Hubbard, Cuimei Xu, Kamil Taneja, Hanzhang Lu, Bart Rypma

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Neural-vascular coupling (NVC) is the process by which oxygen and nutrients are delivered to metabolically active neurons by blood vessels. Murine models of NVC disruption have revealed its critical role in healthy neural function. We hypothesized that, in humans, aging exerts detrimental effects upon the integrity of the neural-glial-vascular system that underlies NVC. To test this hypothesis, calibrated functional magnetic resonance imaging (cfMRI) was used to characterize age-related changes in cerebral blood flow (CBF) and oxygen metabolism during visual cortex stimulation. Thirty-three younger and 27 older participants underwent cfMRI scanning during both an attention-controlled visual stimulation task and a hypercapnia paradigm used to calibrate the blood-oxygen-level-dependent signal. Measurement of stimulus-evoked blood flow and oxygen metabolism permitted calculation of the NVC ratio to assess the integrity of neural-vascular communication. Consistent with our hypothesis, we observed monotonic NVC ratio increases with increasing visual stimulation frequency in younger adults but not in older adults. Age-related changes in stimulus-evoked cerebrovascular and neurometabolic signal could not fully explain this disruption; increases in stimulus-evoked neurometabolic activity elicited corresponding increases in stimulus-evoked CBF in younger but not in older adults. These results implicate age-related, demand-dependent failures of the neural-glial-vascular structures that comprise the NVC system.

Original languageEnglish (US)
Pages (from-to)135-151
Number of pages17
JournalCerebral cortex (New York, N.Y. : 1991)
Issue number1
StatePublished - Dec 15 2022


  • aging
  • calibrated fMRI
  • cerebral blood flow
  • cerebral oxygen metabolism
  • neurovascular coupling

ASJC Scopus subject areas

  • Cognitive Neuroscience
  • Cellular and Molecular Neuroscience


Dive into the research topics of 'Altered linear coupling between stimulus-evoked blood flow and oxygen metabolism in the aging human brain'. Together they form a unique fingerprint.

Cite this