The imaging facility in the Jungers Center for Neurosciences Research houses three state-of-the-art microscopes specifically designed for fluorescence imaging in living cells and organisms. The discovery of green fluorescent protein (GFP) has led to a transformation in our ability to watch how cells work in health and disease. Fluorescent protein technology can be used to monitor gene expression, protein localization and dynamics, protein-protein interactions, and organelle transport. Clever modifications in the structure of GFP allow it to be use as a sensor of pH, ion concentrations, and enzyme activity within different regions of neurons. These approaches can be applied to nearly every important question in neuroscience—from how axons grow and connect together during development, to how synapses change during learning, to how neuronal function is altered in models of neural disease. In recognition of the broad significance of these remarkable developments, the 2008 Nobel Prize for Chemistry was awarded for the discovery and implementation of GFP technology. This technological revolution in imaging is still rapidly evolving – new methods under development will enhance the spatial resolution of light microscopic imaging from the cellular level to the level of individual molecules. Instrumentation to bring this optical “nanoscopy” to the neuroscience laboratory will likely to enter the commercial market in the near future.
The Jungers Imaging Facility offers OHSU neuroscientists imaging setups specialized for capturing dynamic events in different types of specimens. The Zeiss LSM710 laser scanning confocal microscope scans a point of light across the specimen, similar to the technology used in a television. This approach makes it possible to obtain a series of ‘optical sections’ at different levels within the specimen, which can then be rendered into a digital 3D reconstruction of the fluorescence within tissue, or in a small model organism such as a fly or worm. A similar idea is used in the spinning disc confocal microscope, but its mode of image acquisition enables it to capture images much more rapidly than the laser scanning confocal microscope, making this the preferred setup to follow rapid changes in fluorescence. The automated widefield microscope is intended for thinner specimens, like cells in tissue culture. Full automation allows the microscope to follow many different cells at different locations in the culture in order to obtain long-term time-lapse recordings over hours or days.
Gary Banker and Stefanie Kaech direct the Imaging Facility. Banker’s laboratory has pioneered methods to image the transport of proteins in nerve axons in order to determine how this process is disrupted in neurodegenerative disease. His colleague, Stefanie Kaech, was among the first to adapt GFP technology to image the dynamics of living synapses. They offer their expertise in GFP technology to the OHSU neuroscience community, train OHSU researchers in the use of the facility’s instruments, and offer courses and workshops on imaging for graduate students and postdocs.
Stefanie Kaech, Assistant Professor
PhD, Biocenter, University of Basel, 1991
The first time I watched a time-lapse recording of a living cell I became fascinated by the power of digital microscopy. In my opinion, the discovery of GFP and its application to visualize dynamic events inside of cells has revolutionized modern cell biology. I first used this enabling technology to study the structural proteins that give a neuron its shape. One of these cytoskeletal proteins – tubulin – is the building block for the tracks used by motor proteins and my interests in this crucial aspect of neuronal cell biology transported me long-range from Switzerland to the beautiful Northwest of the US of A.