β amyloid-induced disruption of ionic balance:: studies on the isolated frog labyrinth

The beta -amyloid pepticle (A beta) is a key player in the pathogenesis of Alzheimer's disease. Although its mechanisms of action are not fully elucidated, a disruption of ionic homeostasis has been suggested, and A beta aggregation in fibrils seems correlated to its toxic potential. In the present work, we studied the effects of different A beta fragments on the activity of frog ampullar nerve fibers. Our results show that A beta fragments are able to reduce ampullar nerve responses, with a potency correlated to their fibrillogenic capability. This study may have clinical implications, since vestibular problems are often reported in Alzheimer patients, and provide a model for the dissection of AP effects in a simple multicomponent system. NeuroReport 12:2493-2497 (C) 2001 Lippincott Williams & Wilkins.