1. Sections on Clinical NeurocardiologyNational Institutes of Health Bethesda Maryland USA
2. Sections on Neural DevelopmentNational Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda Maryland USA
3. Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health Bethesda Maryland USA
4. Department of Neuroscience, Department of Anatomy, Department of Cell BiologyTufts University Medical School Boston Massachusetts USA