Characterizing the Mechanical Properties of Rat Brain Tissue in Tension

Characterizing the mechanical properties of brain tissue is deemed important for developing a comprehensive knowledge of the mechanisms underlying brain diseases. Mechanical properties of very soft tissues، such as brain until recently have been attracted the attention of researchers because these tissues do not tolerate mechanical loads. The mechanical properties of brain tissue، however، can change in some disease. Plasmodium falciparum (P. falciparum) is one of the hazardous types of malaria that can alter the brain tissue properties by parasitized red blood cell (PRBC). The most severe and challenging complication of P. falciparum infection is cerebral malaria (CM). CM is a clinically complex syndrome and during the CM، PRBCs sequestered in cerebral microvasculature and cause coma and eventually patient will die of it. Therefore it seems noticeable to investigate on variation of mechanical properties of brain tissue after infection. The mixed gray and white matter samples are excised from seven rats which were infected by Plasmodium berghei-ANKA (PbA) strain and two rats as the control group. Then each removed brain tissue is carried out on uniaxial tensile apparatus and the stress-strain diagram for each brain tissue is obtained. The results are shown that with increasing the level of parasitemia from 1. 5% to 6%، the elastic modulus of brain tissue is increased about 3. 44 times. The comparison between the 5. 5% and 6% level of parasitemia is indicated 1. 87 times increasing in elastic modulus. The comparison between the control group (0%) and 6% of parasitemia is depicted more than 4. 07 times increasing in brain tissue stiffness. It can be concluded that، brain’s rigidity is resulted from stiff PRBCs which were sequestered in brain’s microvasculature. This suggests sequestration of the stiffened and less deformable parasitized red blood cells in the brain microvasculature.