Reproducibility for Everyone (R4E) (@repro4everyone.bsky.social)

Repeated head trauma causes neuron loss and inflammation in young athletes | Nature Repetitive head impacts (RHIs) sustained from contact sports are the largest risk factor for chronic traumatic encephalopathy (CTE)1–4. Currently, CTE can only be diagnosed after death and the events that trigger initial hyperphosphorylated tau (p-tau) deposition remain unclear2. Furthermore, the symptoms endorsed by young individuals are not fully explained by the extent of p-tau deposition2, severely hampering therapeutic interventions. Here we observed a multicellular response prior to the onset of CTE p-tau pathology that correlates with number of years of RHI exposure in young people (less than 51 years of age) with RHI exposure, the majority of whom played American football. Leveraging single-nucleus RNA sequencing of tissue from 8 control individuals, 9 RHI-exposed individuals and 11 individuals with low-stage CTE, we identify SPP1-expressing inflammatory microglia, angiogenic and inflamed endothelial cells, astrocytosis and altered synaptic gene expression in those exposed to R https://doi.org/10.1038/s41586-025-09534-6