McConnell_2012_Neurotoxicol_33_1048

Microelectrode array MEA approaches have been proposed as a tool for detecting functional changes in electrically excitable cells including neurons exposed to drugs chemicals or particles However conventional single well-MEA systems lack the throughput necessary for screening large numbers of uncharacterized compounds Recently multi-well MEA mwMEA formats have become available to address the need for increased throughput The current experiments examined the effects of a training set of 30 chemicals on spontaneous activity in networks of cortical neurons grown on mwMEA plates Each plate contained 12 wells with 64 microelectrodes/well for a total of 768 channels Of the 30 chemicals evaluated 23 were known to alter neuronal function in vivo positives including 6 GABAergic and 3 glutamatergic antagonists/agonists 4 pyrethroids 3 metals 2 cholinesterase inhibitors 2 nicotinic acetylcholine receptor agonists valproic acid verapamil and fluoxetine Seven compounds expected to have no effect on neuronal function were tested as negatives glyphosate acetaminophen salicylic acid paraquat saccharin d-sorbitol and amoxicillin Following collection of 33min of baseline activity chemical effects 50muM or highest soluble concentration were recorded for 33min Twenty of the positives altered the mean network spike rate by more than the 14 threshold two standard deviations from the mean for DMSO control The three positives without effect were bifenthrin nicotine and imidacloprid None of the negative compounds caused a change in activity beyond the threshold Based on these results the mwMEA assay has both high sensitivity 87 identification of positive compounds and specificity 100 identification of negative compounds These experiments demonstrate the capacity of mwMEAs to screen compounds for neurotoxic effects mediated by a broad variety of mechanisms.