We are investigating the subcellular localization and effect of overexpressing neuregulin in hippocampal neurons. We observed that neuregulin exists in clusters in hippocampal neurons. We are examining whether these neuregulin clusters associate with specific subcellular compartments. We are also analyzing the effect of overexpressing neuregulin on the morphogenesis of hippocampal neurons. In addition, we are building expressing constructs for different isoforms of neuregulins, and will compare the difference between their subcellular localization and effect on hippocampal neuron development.