Key terms: NMDA receptor, calcium, iron, oxidative stress, MAPK/ERK, hippocampal slices, long-term potentiation These findings underline the relevance of iron in normal neuronal function. We found that iron-dependent generation of hydroxyl radicals is likely to modulate Ca 2+ signaling through RyR calcium channel activation, which, in turn, activates the MAPK/ERK pathway. In this work, we studied the effect of iron in the activation of MAPK/ERK pathway and on Ca 2+ signaling in neuronal PC12 cells. For example, activation of N-Methyl-D-Aspartate receptor results in the production of ROS, which appears to be critical for synaptic plasticity, one of the cellular mechanisms that underlie learning and memory. Recent evidence suggests that reactive oxygen species function as second messenger molecules in normal physiological processes. NÚÑEZ 3ġPhD Program in Cell, Molecular and Neural Biology, Faculty of Sciences, Universidad de Chile 2Fondap Center for Molecular Studies of the Cell and 3 Biology Department and Cell Dynamics and Biotechnology Research Center, Faculty of Sciences, Universidad de Chile PABLO MUÑOZ 1, GABRIELA ZAVALA 3, KAREN CASTILLO 3, PABLA AGUIRRE 3, CECILIA HIDALGO 2 and MARCO T. POSTER PRESENTATION - SHORT COMMUNICATIONĮffect of iron on the activation of the MAPK/ERK pathway in PC12 neuroblastoma cells