Neurons feel the force: New photonic tools to unravel the development of the nervous system

The development of the central nervous system (CNS) is one of the most spectacular processes in biology. Key aspects include the formation of neuronal axons, their subsequent growth and guidance through thick layers of nerve tissue, and the folding of the brain. All these processes involve motion and are driven by forces. However, while our understanding of the biochemical and molecular control of these processes is increasing rapidly, the contribution of the dynamic interplay between cellular forces and tissue elasticity remains poorly understood – mostly due to a lack of suitable measurement techniques. 

To address this need, in this interdisciplinary project, we will integrate expertise in optics, biophysics and neurobiology to investigate the role of mechanics in CNS development. We propose the construction of a novel photonic toolbox for in situ, label-free and non-contact measurements of cellular forces and elasticity. The project features an international collaboration between Kristian Franze (Cambridge, UK), Malte Gather (Dresden, Germany) and Giuliano Scarcelli (Maryland, USA). 
 
Force sensing (Gather) will be based on spatially mapping nanoscale deformations of an ultra-flexible planar optical microcavity in response to local stress. Elasticity measurements (Scarcelli) will be based on high-resolution Brillouin microscopy. Force and elasticity measurements will be combined to illuminate how forces exerted by neurons contribute to axon formation and neuronal guidance (Franze).
 
Need to include schematic - Schematic of the multimodal microscope combining microcavity-force sensing and Brillouin-elasticity sensing. "Photo is the 3D elasticity map of a cell. So it is the result of one of the 2 instruments described in the word file. Still not neurons though"
 
Giuliano Scarcelli
Fischell Department of Bioengineering
A. James Clark School of Engineering
University of Maryland