Soft Brains, Signal Amplification through Noise, and Taking the Bull by its Horns
报告人：Josef A. K?s 教授 德国莱比锡大学
For the brain’s viscoelastic properties （粘弹性，即生物力学性质) single cell measurements reveal the softness of neurons and Glial cells. The mechanosensitive neurons follow in their growth and development the even softer Glial cells. Growth cone motion, the leading motile structure of growing neurons,is determined by competition of stochastic processes responsible for forward and backward movement. Noise tuning of the growth cone’s fluctuations increases neuronal sensitivity to chemotaxis. Spatial interplay of random actin polymerization driving the forward motion and molecular motor-based retrograde flow responsible for stochastic retraction events can be visualized by applying conservation laws (continuity equation and force balance) to genetically altered neurons. By a simple mechanical lever arm effect weak optical gradient forces acting on the spike-like filopodia, the exploring “horns” of growth cones, are sufficient to control the direction of growth cones stochastic forward motion.