Amyloid beta modulation of neuronal network activity in vitro

In vitro assays offer a means of screening potential therapeutics and accelerating the drug development process. Here, we utilized neuronal cultures on planar microelectrode arrays (MEA) as a functional assay to assess the neurotoxicity of amyloid-beta 1-42 (A beta(42)), a biomolecule implicated in the Alzheimer's disease (AD). In this approach, neurons harvested from embryonic mice were seeded on the substrate-integrated microelectrode arrays. The cultured neurons form a spontaneously active network, and the spiking activity as a functional endpoint could be detected via the MEA. A beta(42) oligomer, but not monomer, significantly reduced network spike rate. In addition, we demonstrated that the ionotropic glutamate receptors, NMDA and AMPA/kainate, play a role in the effects of A beta(42) on neuronal activity in vitro. To examine the utility of the MEA-based assay for AD drug discovery, we tested two model therapeutics for AD, methylene blue (MB) and memantine. Our results show an almost full recovery in the activity within 24 h after administration of A beta(42) in the cultures pre-treated with either MB or memantine. Our findings suggest that cultured neuronal networks may be a useful platform in screening potential therapeutics for A beta induced changes in neurological function. (C) 2015 Elsevier B.V. All rights reserved.