BBB seminar: Winfried Denk
Watching the brain compute and tracing its wires: new methods to solve old riddles
Department of Biomedical Optics, Max Planck Institute for Medical Research, Heidelberg, Germany
Volume-imaging methods are crucial to the understanding of organ function. No organ is more interconnected in 3 dimensions than the brain, with each neuron typically having thousands of neighbors. At one extreme are imaging methods that allow us to map activity in the intact – preferably awake – brain. Among those the only method with sub-cellular 3D resolution is multi-photon microscopy, which we have extended to imaging depths of close to 1000 microns and have shown to operate on behaving animals. At the other extreme are methods, mostly based on electron microscopy, that provide images at deep sub-micron resolution. We have recently developed serial block-face scanning electron microscopy (SBFSEM), which allows the acquisition of intrinsically aligned volume data at a resolution sufficient to trace the thinnest neural processes with the goal to completely reconstruct neural circuits.
Host: Clive Bramham, Department of Biomedicine
Professor Winfried Denk is a pioneer of microscopic techniques for exploring brain function in live animals at the cellular and subcelluar levels. He is widely recognized for his groundbreaking development of multiphoton laser-scanning microscopy for imaging deep within the cerebral cortex, and his innovative combination of this method with whole-cell voltage clamp recording of single neurons in live animals.
Selected papers: Helmchen, F. and Denk, W. Deep tissue two-photon microscopy. Nat Methods 2, 932-940 (2005). Denk, W. and Horstmann, H. Serial block-face scanning electron microscopy to reconstruct three-dimensional tissue nanostructure. PLoS. Biol. 2, e329 (2004).