Abstract
In a recent study, Hervas et al. extracted Orb2 fibrils, that are involved in long-term memory formation, from Drosophila brains, characterised their function, and determined their structure using cryo-electron microscopy (cryo-EM). The fibrils show a remarkable resemblance to amyloid β (Aβ) fibrils associated with Alzheimer's disease, highlighting the subtle difference between functional and dysfunctional amyloid.