Recent progress in the elucidation of the mechanisms of chemotherapy-induced cognitive impairment

The term "chemobrain" refers to the cognitive dysfunction that occurs after chemotherapy, and it is also known as chemotherapy-induced cognitive impairment or "chemofog". The aim of this review is to bring together the findings of existing literature on the topic and summarize the current knowledge on the potential mechanisms of chemobrain. According to the reviewed studies, the mechanisms by which chemotherapy could cause chemobrain include disruption of hippocampal cell proliferation and neurogenesis, hormonal changes, increased oxidative stress and reactive oxygen species production, chronic increase in inflammation, and alterations in synaptic plasticity and long-term potentiation. While the effects of inflammation and oxidative stress on neurogenesis and their role in chemotherapy-induced cognitive impairment have been widely studied, the chemotherapy-induced cognitive impairment mechanisms that involve mitochondrial dysfunction, estrogen dysregulation, and increased transglutaminase 2 are still unclear. Further studies on these mechanisms are necessary to understand the effects of chemotherapy at the cellular and molecular level and facilitate the development of preventive and therapeutic strategies against chemotherapy-associated cognitive impairment or chemobrain.