複雑生命システム動態研究教育拠点


Date: 13. Sep. 2013, 11:00-12:30
Room 410, The Advanced Research Laboratory, Komaba 1 campus, University of Tokyo

Towards a biophysics of organisms: Stochastic dynamics in the reversal motions of C. elegans.


Speaker:
Greg Stephens
Assistant Professor
Biological Physics Theory Unit
Okinawa Institute of Science and Technology



Abstract:

While there has been an explosion in our ability to characterize the molecules, cells, and circuits that generate natural b ehavior, our understanding of behavior itself is less advanced.
Here we use high-resolution video microscopy to record the motions of the nematode C. elegans, freely-wiggling on a flat ag ar plate.
We show that the space of shapes is low-dimensional, with just four dimensions accounting for 95% of the shape va riance.
Projections of worm shape along these four “eigenworms” provide a precise yet substantially complete description of locomotory behavior, capturing both classical motion such as forward crawling, reversals, and Ω-turns and novel behavio rs such as “pause” states at particular postures.
We use the eigenworms to construct a stochastic model of the body wave dynamics that predicts transitions between attractors corresponding to abrupt reversals in crawling direction and we show th at the noise amplitude decreases systematically with increasing time away from food, resulting in longer bouts of forward cr awling and suggesting that worms use noise to adaptive benefit.


see also http://rcis.c.u-tokyo.ac.jp/seminar.html