research project 2
Neuronal nanodetection and micro-patterning, engineering sensory neurons for function
Li-Yang Chiang, Jing Hu, and Kate Poole
The mechanosensitive ion channels that are expressed by sensory can be measured using high-resolution electrophysiology techniques. We have recently shown that such ion channels in the membranes of cultured DRG neurons can be activated by stimuli in the nanometer range. We have also gathered considerable evidence that the mechanosensitive channels are actually opened via a protein tether that attaches to laminin-containing extracellular matrices. In order to study the influence of different extracellular matrices on mechanotransduction and to quantify the tiny forces that are required to open mechanosensitive channels we have started to a use variety of new micro-fabrication techniques. For example, we have used micro-patterning of matrix molecules in order force neurons in culture to adopt morphologies that better match the in vivo situation. We can also use such patterning to test the local influence of specific matrix molecules on transduction ability or axon branching behavior. We have shown that sensory neurons can be made to grow to produce highly structured patterns in vivo (see Figure 1). Another application of micro-engineering is to make neurons grow on three dimensional surfaces that allow us to gauge the forces needed to open mechanosensitive ion channels in single cells.
1. Hu, J., Chiang, L., Koch, M. & Lewin, G.R. Evidence for a protein tether involved in somatic touch. EMBO J 29, 855-867 (2010).
2. Hu, J. & Lewin, G.R. Mechanosensitive currents in the neurites of cultured mouse sensory neurones. The Journal of physiology 577, 815-28 (2006).
3. Chiang LY; Poole K; Oliveira BE; Duarte N; Bernal Sierra YA; Bruckner-Tuderman L; Koch M; Hu J; Lewin GR. Laminin-332 coordinates mechanotransduction and growth cone bifurcation in sensory neurons. Nature Neuroscience 14(8): 993-1000 (2011-07-03)
4. Heidenreich M; Lechner SG; Vardanyan V; Wetzel C; Cremers CW; De Leenheer EM; Aranguez G; Moreno-Pelayo MA; Jentsch TJ; Lewin GR. KCNQ4 K(+) channels tune mechanoreceptors for normal touch sensation in mouse and man. Nature Neuroscience : (2011-11-20)