Module 12: Figure LTD hypothesis of Alzheimer's disease
LTD hypothesis of Alzheimer's disease.
During the day, brief high concentration (1000 nM) spikes of Ca2+ are responsible for activating long-term potentiation (LTP) that form memories that are held in a temporary memory store. At night, these temporary memories are consolidated following their transfer to a permanent memory store during sleep. The memories in the temporary store are then erased by a period of intermediate elevation of Ca2+ (approximately 300 nM). In Alzheimer's disease, amyloid metabolism results in a permanent elevation of Ca2+ into this intermediate range that continuously erase memories from the temporary memory store soon after they are formed. Memories can still be formed by brief high-intensity spikes of Ca2+, but the persistent amyloid-dependent elevation of Ca2+ erases these temporary memories before they can be transferred to the permanent memory store.