Project Summary Chemotherapy is an extremely effective treatment for cancer; however, along with chemotherapy’s benefits there are many undesirable consequences including chemotherapy-related cognitive impairments (CRCI) and accelerated aging. Despite impacts on quality of life, these areas are relatively understudied and there are currently no FDA approved treatments available. A sophisticated animal model to address this problem will be extremely valuable, both to our understanding of the long-term consequences and to the development of potential treatments. Currently, CRCI and chemotherapy-related accelerated aging is studied in rodents, but a nonhuman primate model will significantly enhance the validity of studies addressing this still under-researched phenomenon. In this proposed study, we aim to establish a baboon model of CRCI and accelerated aging. We will further define healthy aging in a baboon sample, then investigate whether chemotherapy induces cognitive decline and accelerates brain aging in baboons as it does in humans and test an intervention which has been effective in mice. We will collect brain imaging, cognitive, and aging molecular biomarker data from baboons prior to treatment with cisplatin only or cisplatin followed by an HDAC6 inhibitor. We will then collect further brain, cognitive, and aging data post-treatment to examine changes related to the chemotherapy regimen and whether the HDAC6 inhibitor reverses cognitive declines and neurodegeneration. These data will be used to propose further studies as well as techniques to potentially mitigate these consequences of chemotherapy in humans.