1. A Comparative Analysis of Centrosome and Soma Migration in Neurons Rachel Boerner Calvin College Richard Ward Computational Sciences and Engineering Ryan Kerekes Measurement Science and Systems Engineering August 2009

2. 2Managed by UT-Battelle for the U.S. Department of Energy Overview Background Previous work Methods Results Future work

3. 3Managed by UT-Battelle for the U.S. Department of Energy Neuron structure Basic structures Somas Axons Dendrites Centrosomes http://serendip.brynmawr.edu/bb/kinser/definitions/def-neuron.html Axon Soma Dendrites Actual images of cerebral neurons

4. 4Managed by UT-Battelle for the U.S. Department of Energy Neuron function and migration Function determines structure Migrate http://www.mind.ilstu.edu/curriculum/neurons_intro/neurons_intro.php Migrating neuron along radial glial cell http://glia-uab.infomedia.com/content.asp?id=104968 Examples of different neuron structures based on their function

5. 5Managed by UT-Battelle for the U.S. Department of Energy St. Jude Children’s Research Hospital Neurons migrate during the utero stage or early years of development Abnormal neuron migration has been linked to certain diseases St. Jude’s interested in tracking the neurons for diagnostic purposes Images taken with a Marianas spinning disk confocal microscope Hundreds of images waiting to be manually analyzed Weeks to go through one data set

6. 6Managed by UT-Battelle for the U.S. Department of Energy Oak Ridge National Laboratory Centrosome detection and tracking Filter Threshold Search for small, round, bright objects Use joint probabilistic data association filter (above) A three dimensional plot of centrosome movement in the x-, y-, and z-directions. (above) The right image shows the detections made by Ryan's code. The left image is those detections locations superimposed on the original image.

7. 7Managed by UT-Battelle for the U.S. Department of Energy Current Work Different color schemes show more details

8. 8Managed by UT-Battelle for the U.S. Department of Energy Method Attempted method Gradient and fill Centroid (left) An image after a rotationally symmetric Gaussian lowpass filter is applied. (center) The image after thresholding for intensity and distance from the center of an object. (right) The segmentation of the somas based on regions being larger than a certain radius. Actual method Euclidean transform equation Thresholding Sequence of attempted code for soma segmentation

9. 9Managed by UT-Battelle for the U.S. Department of Energy Results Analyzed visually See random motion Centrosomes move at an average speed of 0.1 μm Somas move at an average speed of 0.03 μm Not much correlation between soma and centrosome migration Chemicals inhibited cell motion Centrosome and soma pairs are difficult to match (below) This graph is the plot of the motion of the soma throughout the various timeframes. Each pixel corresponds to 0.15 μm. (above) The graphs are 3D images of the detections and tracks of somas and centrosomes. The red marks the soma tracks and the blue corresponds to the centrosome tracks. The images were taken ever 16 seconds.

10. 10Managed by UT-Battelle for the U.S. Department of Energy Conclusion Developed code for soma segmentation Detected no correlation between soma and centrosome motion Analyze neuron migration in three dimensions Study and track actin movement Recognize patterns of behavior between neuron migration and specific diseases Build techniques for the alteration or prevention of abnormal neuron migration Future Work

11. 11Managed by UT-Battelle for the U.S. Department of Energy Bibliography R. A. Kerekes, S. S. Gleason, N. Trivedi, and D. J. Solecki, “Automated 3-D tracking of centrosomes in sequences of confocal image stacks,” submitted to EMBC `09, Minneapolis, 2009. "Neuron." Serendip. 2003. 20 July 2009. McCoy, Eric. "Glia as Guides for Neuronal Migration,." UAB Center for Glial Biology in Medicine. UAB. 22 July 2009. "ORNL, St. Jude track neurons to predict and prevent disease." The Oak Ridger, 30 March 2009, sec. A3. Stufflebeam, Robert. "Neurons, Synapses, Action Potentials, and Neurotransmission." Consortium on Cognitive Science Instruction. 2008. The Mind Project. 22 July 2009.

12. 12Managed by UT-Battelle for the U.S. Department of Energy Acknowledgements I would like to thank Richard Ward and Ryan Kerekes for the opportunity to work on this project. Also, thanks to Debbie McCoy, who made provisions for this research experience.

13. 13Managed by UT-Battelle for the U.S. Department of Energy Questions?