Effects of swelling on brain tissue mechanical properties by indentation

Abstract

Constructing more in-depth models of the brain’s behavior has gained significant attention in recent years, particularly for the goal of modeling brain injury and function. Mechanical studies have improved in effectiveness with the development of more standard testing protocols and the contribution of mechanistic models to understanding the brain’s behavior. Due to the complexity of the brain’s structure and pathophysiology of diseases and conditions related to swelling, studies have mainly focused on identifying the mechanisms underlying brain tissue swelling. Most commonly, magnetic resonance imaging techniques have been used, particularly with the development of magnetic resonance elastography, to study swelling in vivo. However, localized testing on in vitro tissue slices have become useful alternatives as models of study with atomic force microscopy and nanoindentation. Here, the method of nanoindentation is applied to brain tissue slices to identify the effects of swelling on the tissue’s mechanical properties. The stiffness and relaxation properties of brain tissue slices are identified, suggesting a useful and simple alternative to in vivo imaging for identifying the effects of diseases such as edema or hydrocephalus on the brain.