Highlight
Retreat on New Imaging Techniques
Achievement/Results
The Volen Center for Complex Systems Retreat, 2011 by Al Hamood and Tilman Kispersky)
The annual Volen Center Retreat was held this week at the bucolic Warren Conference Center and Retreat in Ashland, Massachusetts. The purpose of the one-day retreat is to provide a forum for conversation and encourage collaborations between members of the Brandeis community. The retreat features a distinguished invited speaker, lectures from Volen faculty that highlight the diversity of Neuroscience research at the Center and a poster session covering ongoing research projects of the members of the community. IGERT trainees presented posters.
The director of the Volen Center, Prof. Arthur Wingfield began the proceedings with a brief history of the retreat which is in its 17th consecutive year. While historically the most common location for the retreat has been the Marine Biological Labs in Woods Hole, MA the retreat was held at the 220 acre property of the Warren Conference Center outside of Framingham this year. Prof. Wingfield introduced the theme of the retreat: “Imaging: Recent breakthroughs in visualization – from synapses to circuits”. Each lecture focused on data collected with advanced imaging techniques and highlighted how advanced optical methods had enabled a deeper understand of nervous system.
Lectures
The first lecture was given by Prof. Aniruddha Das from the Columbia University Department of Neuroscience. Prof. Das’ research group developed a method to perform dual-wavelength imaging to measure both the volume of blood present in a given region of cortex as well as the oxygenation level of that blood, two quantities that are combined in traditional fMRI imaging. Using dual-wavelength imaging Prof. Das found a task-related anticipatory haemodynamic signal in the visual cortex of awake monkeys. This signal was unrelated to either single unit activity or any visual stimulation. The finding suggests that cortical circuits increase their blood oxygenation level prior to the expected onset of a task in anticipation of the increased computational load.
The second speaker was Brandeis Professor Stephen Van Hooser. Prof. Van Hooser studies motion detection in the visual system and is specifically interested in how motion selectivity develops and what role sensory inputs play in this process. The ferret visual system, the animal model used by Prof. Van Hooser, develops orientation selectivity prior to receiving any sensory input. However, motion selectivity requires visual inputs and thus develops later, after young ferrets open their eyes. Prof. Van Hooser presented experimental results that employed two-photon imaging to simultaneously measure the activation of hundreds of cells at depths of up to 300 um beneath the cortical surface. By presenting moving visual stimuli Prof. Van Hooser was able to track the emergence of motion selectivity in cortical neurons and was able to influence the course of development by changing the direction of motion of the stimulus.
Following the mid-day poster session, the afternoon portion of the retreat featured a trio of talks covering some of the cutting-edge imaging work currently being done at Brandeis. First up was Dr. Avital Rodal (pictured at right), whose lab employs an innovative, high speed confocal microscopy technique to capture high-resolution images of tagged endosomes on the move in developing fly neurons. By combining different markers in the same experiment, Dr. Rodal has been able to demonstrate transient interactions, undetectable by traditional methods. Potentially, her work could help us understand a range of health issues in which endosomal trafficking has been implicated, including neurodegenerative disease and mental retardation. See the moving endosomes for yourself in a recent blog post covering her exciting work!
The next speaker was able to remind us that sometimes it takes more than biologists to do biology — especially when the task is high-throughput image analysis. Dr. Pengyu Hong, an Assistant Professor of Computer Science here at Brandeis, shared some of his work using High Content Screening, an automated method of analyzing image data and extracting information about cellular phenotypes and neurite length from images of cell cultures. Using data provided by his collaborators around the world, his method is able to quantify neuronal morphology, allowing for high throughput genetic and drug discovery screening at improved levels of accuracy — a previously intractable task.
The final speaker of the retreat shared with us an intriguing work in progress. Dr. David DeRosier (pictured at left), Brandeis Emeritus Professor of Biology, currently a member of the Turrigiano lab, has been developing an imaging technique called “Cryo-PALM”. If it sounds cool, it’s much more than that; it involves holding a biological sample frozen at no more than -140C, while imaging it with a room temperature microscope objective less than a millimeter away. It sounds difficult — and as David told us, it is! — but the potential is huge. Dr. DeRosier hopes to be able to precisely localize fluorescently labeled proteins in the synapse down to sub-nanometer resolution, and provide the most detailed picture ever of synaptic structure.
Address Goals
The Retreat demonstrated a variety of new imaging techniques and their application to a variety of problems. The Retreat directly demonstrated the importance of physics for the understanding of biological systems, and brought together people from many departments and programs around a series of important problems.
