Abstract:

With the rapid growth of neuroscience studies in recent years, the essential role of mechanical and physical stimuli, besides conventional biochemical cues, in various neurological processes has been widely recognized. For this reason, the field of neuron mechanics, studying how mechanical forces influence the behavior of neural cells, has received increasing attention, especially when investigating phenomena like axon outgrowth, neuronal injury and repair.

This seminar will present our recent work in neuron mechanics. Specifically, I will discuss our effort in developing an AFM-based in vitro method to quantitatively examine the injury response of neurons. We showed that the retracting motion of a well-developed axon can be arrested by strong neuron-substrate adhesion and axonal retraction could be re-triggered, albeit with a lower amplitude, if a second transection was introduced. In addition to retraction, beading of transected axon was also observed, with the beading wavelength tightly correlated with the integrity of the axonal cytoskeleton. After that, mechanical stress induced signal activation within neurons will be discussed. In particular, we found that the threshold compressive stress for triggering calcium response in dorsal root ganglions, with TRPV1 highly expressed, decreases from 6.7 kPa to almost zero when medium osmolarity increases from 300 (isotonic) to 330 mOsm. On the other hand, this threshold stress increases with increasing surrounding osmolarity in cells where TRPV1 is inhibited, highlighting its critical role in the mechano-transduction of neurons.  Finally, I will discuss our on-going effort in development a micro-loading platform for studying the force-regulated signal transmission between neural cells.

ALL INTERESTED ARE WELCOME