Measurement of the uniaxial mechanical properties of rat brains infected by Plasmodium berghei ANKA.

Degenerative and demyelinating diseases are known to alter the mechanical properties of brain tissue. While few studies have characterized these biomechanical changes, it is clear that accurate characterization of the mechanical properties of diseased brain tissue could be a substantial asset to neuronavigation and surgery simulation through haptic devices. In this study, samples of brain tissue from rats infected with Plasmodium berghei ANKA, an African murine malaria parasite, are evaluated using a uniaxial tensile test machine. Infected brains having different levels of parasitemia are mounted on the testing machine and extended until failure of the tissue. The stress-strain curve of each sample is obtained and compared to healthy rat brain tissue. Young's modulus of each sample is extracted from the Hookean part of the stress-strain diagram. Young's modulus of rats' brain shows considerable difference among the samples having various levels of parasitemia compared with the controls. For instance, the brains with 0% (control), 1.5%, and 9% parasitemia showed a Young's modulus of 46.15, 54.54, and 266.67 kPa, respectively. This suggests sequestration of the stiffened and less deformable parasitized red blood cells in the brain microvasculature.