Plaque-f ree dementia

摘要

Danish dementia is a rare condition that resembles Alzheimer's disease, but is caused by an autosomal domi- nant mutation in the BRI2/ITM2b gene. The popular Amyloid Cascade hypothesis attributes genetic forms of dementia to the accumulation of amyloid plaques in the brain. But recent studies have shown that large amyloid plaques do not impair cognition or memory in a young transgenic mouse model of Danish dementia, suggesting that another mechanism may contribute to the disease. Robert Tamayev et al. (pp. 20822-20827) studied knock-in mice that, similar to humans with Danish dementia, exhibited reduced expression of Bri2 and severe memory loss as well as reduced plasticity in the nervous system. The mice developed symptoms of Danish dementia without the accumulation of amyloidogenic peptide plaques.