BDNF and early-onset autosomal dominant Alzheimer disease: In contrast, sustained patterns of neural network activity may promote the spread of specific proteinopathies (“molecular nexopathies”) (Warren et al., 2013), and BDNF expression might be one mediator of such activity-dependent network degenerations in the setting of proteinopathies, as recently also demonstrated in Alzheimer's disease (Hardy et al., 2017).