David I. Shreiber

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Although glia have been historically classified as the structurally supporting cells of the central nervous system, their role in tissue mechanics is still largely unstudied. The influence of myelin and glia on the mechanical properties of spinal cord tissue was examined by testing embryonic day 18 chick embryo spinal cords in uniaxial tension following(More)
Damage to axons and glial cells in the central nervous system (CNS) white matter is a nearly universal feature of traumatic brain injury, yet it is not clear how the tissue mechanical deformations are transferred to the cellular components of the CNS. Defining how cellular deformations relate to the applied tissue deformation field can both highlight(More)
The microkinematic response of axons to mechanical stretch was examined in the developing chick embryo spinal cord during a period of rapid growth and myelination. Spinal cords were isolated at different days of embryonic (E) development post-fertilization (E12, E14, E16, and E18) and stretched 0%, 5%, 10%, 15%, and 20%, respectively. During this period,(More)
The lack of practicable nonlinear elastic contact models frequently compels the inappropriate use of Hertzian models in analyzing indentation data and likely contributes to inconsistencies associated with the results of biological atomic force microscopy measurements. We derived and validated with the aid of the finite element method force-indentation(More)
The dura mater is the outermost and most substantial meningial layer of central nervous system (CNS) tissue that acts as a protective membrane for the brain and spinal cord. In animal models of traumatic brain injury and spinal cord injury, mechanical insults are often delivered directly to the dura to injure the underlying tissue. As such, including a(More)
Primary damage to the blood-spinal cord barrier (BSCB) is a nearly universal consequence of spinal cord injury that contributes significantly to the overall pathology, including the introduction of reactive species that induce cytotoxicity as well as secondary insults on the BSCB itself. We have characterized quantitatively the extent and severity of(More)
When subject to applied electric pulses, a lipid membrane exhibits complex responses including electrodeformation and electroporation. In this work, the electrodeformation of giant unilamellar vesicles under strong dc electric fields was investigated. Specifically, the degree of deformation was quantified as a function of the applied field strength and the(More)
Axonal injury represents a critical target area for the prevention and treatment of traumatic brain and spinal cord injuries. Finite element (FE) models of the head and/or brain are often used to predict brain injury caused by external mechanical loadings, such as explosive waves and direct impact. The accuracy of these numerical models depends on correctly(More)
Mechanical damage to axons is a proximal cause of deficits following traumatic brain injury and spinal cord injury. Axons are injured predominantly by tensile strain, and identifying the strain experienced by axons is a critical step toward injury prevention. White matter demonstrates complex nonlinear mechanical behavior at the continuum level that evolves(More)
Single-unit recording neural probes have significant advantages towards improving signal-to-noise ratio and specificity for signal acquisition in brain-to-computer interface devices. Long-term effectiveness is unfortunately limited by the chronic injury response, which has been linked to the mechanical mismatch between rigid probes and compliant brain(More)