Insights into the Microstructural Origin of Brain Viscoelasticity

Abstract Mechanical aspects play an important role in brain development, function, and disease. Therefore, continuum-mechanics-based computational models are a valuable tool to advance our understanding of mechanics-related physiological pathological processes the brain. Currently, mainly phenomenological material used predict behavior tissue numerically. The model parameters often lack physical interpretation only provide adequate estimates for regions which have similar microstructure age as those calibration. These issues can be overcome by establishing advanced constitutive that microstructurally motivated account regional heterogeneities through microstructural parameters. In this work, we perform simultaneous compressive mechanical loadings analyses porcine identify mechanisms underlie macroscopic nonlinear time-dependent response. Based on experimental insights into link between mechanics cellular rearrangements, propose microstructure-informed finite viscoelastic tissue. We determine relaxation time constant from displacement curves introduce hyperelastic linear functions cell density, determined histological staining tested samples. is calibrated using combination cyclic stress experiments compression. presented considerations constitute step towards microstructure-based tissue, may eventually allow us capture how changes during aging, disease affect mechanics.