Chronic 14-day exposure to insecticides or methylmercury modulates neuronal activity in primary rat cortical cultures.

There is an increasing demand for in vitro test systems to detect neurotoxicity for use in chemical risk assessment. In this study, we evaluated the applicability of rat primary cortical cultures grown on multi-well micro-electrode arrays (mwMEAs) to detect effects of chronic 14-day exposure to structurally different insecticides or methylmercury on neuronal activity (mean spike rate; MSR). Effects of chronic exposure to α-cypermethrin, endosulfan, carbaryl, chlorpyrifos(-oxon), methylmercury or solvent control [14days exposure, initiated after baseline recording at day in vitro (DIV)7] were studied in five successive recordings between DIV10 and DIV21.