Article,
Mouse brain elastography changes with sleep/wake cycles, aging, and Alzheimer's disease
Contributors
Ge G.R.
0000-0001-9765-8076
[1]
Giannetto M.J.
0000-0002-4338-8709
[2]
Nedergaard M.
0000-0002-9254-5360
(Corresponding author)
[2]
[4]
Parker K.J.
0000-0002-6313-6605
(Corresponding author)
[2]
Affiliations
- [1] University of Rochester [NORA names: United States; America, North; OECD];
- [2] University of Rochester Medical Center [NORA names: United States; America, North; OECD];
- [3] University of Rochester [NORA names: United States; America, North; OECD];
- [4] University of Copenhagen [NORA names: KU University of Copenhagen; University; Denmark; Europe, EU; Nordic; OECD]
Abstract
Understanding the physiological processes in aging and how neurodegenerative disorders affect cognitive function is a high priority for advancing human health. One specific area of recently enabled research is the in vivo biomechanical state of the brain. This study utilized reverberant optical coherence elastography, a high-resolution elasticity imaging method, to investigate stiffness changes during the sleep/wake cycle, aging, and Alzheimer's disease in murine models. Four-dimensional scans of 44 wildtype mice, 13 mice with deletion of aquaporin-4 water channel, and 12 mice with Alzheimer-related pathology (APP/PS1) demonstrated that (1) cortical tissue became softer (on the order of a 10% decrease in shear wave speed) when young wildtype mice transitioned from wake to anesthetized, yet this effect was lost in aging and with mice overexpressing amyloid-β or lacking the water channel AQP4. (2) Cortical stiffness increased with age in all mice lines, but wildtype mice exhibited the most prominent changes as a function of aging. The study provides novel insight into the brain's biomechanics, the constraints of fluid flow, and how the state of brain activity affects basic properties of cortical tissues.
