These proinflammatory cytokines disrupt the production of plasticity-related molecules such as BDNF (brain-derived neurotrophic factor) and IGF-1 (insulin-like growth factor 1), which impairs synaptic plasticity and neuronal function, causing brain damage and leading to neurodegenerative diseases like Alzheimer’s disease, Parkinson’s disease, and stroke.64 Here, BDNF is linked to neurodegenerative disease.