When glial proliferation in primary neuronal cultures was inhibited with 1 μM cytosine arabinoside (AraC), followed by infection with RML or uninfected CD1 control homogenates, Map2-positive neurons with fibril-like PrPd aggregates were visible upon RML infection (Fig. 1I), demonstrating that this fibrillar PrPd phenotype is prevalent in neurons as well. The gene discussed is MAP2; the disease is infection.