五、閱讀測驗(32%)
36.至39.題為題組
         A Cambridge research team studied young and old rat brains to understand the impact of age- relatedbrain stiffening on the function of oligodendrocyte progenitor cells (OPCs). These cells are a type of brainstem cell important for maintaining normal brain function, and for the regeneration of myelin – a protectivecover that surrounds our nerves. Myelin is damaged in multiple sclerosis (MS), a disease in nervous system,which causes physical, mental, and even psychiatric problems. The effects of age on OPCs contributes toMS, but OPCs also gradually lose their function with age in healthy people.
         To determine whether the loss of function in aged OPCs in reversible, the researchers transplantedolder OPCs from aged rats into the soft, spongy brains of younger animals. Remarkably, the older braincells were rejuvenated, and began to behave like the younger, more vigorous cells.
         To fully understand how brain softness and stiffness influences cell behavior, the researchersinvestigated Piezol – a protein found on the cell surface, which informs the cell whether the surroundingenvironment is soft or stiff. When Piezol was removed from the surface of aged brain stem cells, they weretricked into perceiving a soft surrounding environment, even when they were growing on the stiff material.Moreover, when Piezol was deleted in the OPCs within the aged rat brains, the cells becoming rejuvenatedand once again able to assume their normal regenerative function.
         Dr. Susan Kohlhass stated, “The Cambridge team’s discoveries on how brain cells age and how thisprocess might be reversed have important implications for future treatment for MS, because it gives us anew target to address issues associated with aging and MS, including how to regain lost function in thebrain.”
【題組】36. What is the main purpose of this research?
(A) To investigate how myelin is function in MS.
(B) To learn more about the origin of the gene, Piezol.
(C) To know more about oligodendrocyte progenitor cells (OPCs).
(D) To understand more about the disease, multiple sclerosis (MS).