Dr. McMahan's lab uses three-dimensional reconstructions of tissue sections generated by electron microscope tomography to study the organization and behavior of macromolecules at the nervous system’s synapses. The information we obtain provides insights unobtainable in any other way about the molecular mechanisms involved in synaptic impulse transmission and the sequence of steps in synapse formation. To augment our studies we are developing methods for localizing known proteins to specific macromolecules observed by tomography and for the quantitative analysis of tomographic data, technologies that can be applied to the investigation of macromolecules in any tissue.