Amyloid-β Effects on Peripheral Nerve: A New Model System

Although there are many biochemical methods to measure amyloid-beta (A beta)42 concentration, one of the critical issues in the study of the effects of A beta 42 on the nervous system is a simple physiological measurement. The in vitro rat sciatic nerve model is employed and the nerve action potential (NAP) is quantified with different stimuli while exposed to different concentrations of A beta 42. A beta 42 predominantly reduces the NAP amplitude with minimal effects on other parameters except at low stimulus currents and short inter-stimulus intervals. The effects of A beta 42 are significantly concentration-dependent, with a maximum reduction in NAP amplitude at a concentration of 70 nM and smaller effects on the NAP amplitude at higher and lower concentrations. However, even physiologic concentrations in the range of 70 pM did reduce the NAP amplitude. The effects of A beta 42 became maximal 5-8 h after exposure and did not reverse during a 30 min washout period. The in vitro rat sciatic nerve model is sensitive to the effects of physiologic concentrations of A beta 42. These experiments suggest that the effect of A beta 42 is a very complex function of concentration that may be the result of amyloid-related changes in membrane properties or sodium channels.

Automated summary

This study used an in vitro rat sciatic nerve model to investigate the effects of A beta 42 on the nervous system. The results showed that A beta 42 primarily reduces the amplitude of the nerve action potential, and this effect is significantly concentration-dependent.