Nano mechanics of cells and materials
There is increasing experimental evidence suggesting that extracellular and intracellular mechanical forces, and mechanical micro-environment have a profound influence on a wide range of cell behavior such as growth, differentiation, apoptosis, gene expression, adhesion and signal transduction. Neurons are no exception. We are interested in exploring how neurons respond to their mechanical micro-environment. We have shown, using embryonic fruit flies and nano scale sensors, that motor neurons generate tensile force within two ours of synaptogenesis. This force seems to be essential in clustering neurotransmitter vesicles at the pre-synaptic terminal. Axons of motor neurons maintain this rest tension actively. We are exploring the origin of this force, and its role in axonal transport and vesicle clustering at the presynaptic terminal. We are also studying the effect of force or stretch on the post-synaptic activation using mouse brain slice and crayfish neuro muscular junctions. Our long term goal is to understand the role of forces and the mechanical micro-environment on neuronal function, plasticity and ultimately memory and learning.
Xin Tang, Alireza Tofangchi, Sandeep V. Anand, and Taher A. Saif. (2014) A novel cell traction force microscopy to study multi-cellular systems. Plos Computational Biology, 10(6), e1003631, June 5, 2014, DOI: 10.1371/journal.pcbi.1003631
Ahmed, W. and T. A. Saif. (2014) Active transport of vesicles in neurons is modulated by mechanical tension. Scientific Reports 4, Article number: 4481, March 27, 2014.
Ahmed W., B. Williams, A. Silver, and T. A. Saif. (2013) Measuring the non-equilibrium vesicle dynamics in neurons under tension. Lab on a Chip, 2013 (DOI:10.1039/C2LC41109A).
Tang, X., M. Y. Ali, and M. T. A. Saif. (2012) A novel technique for micro-patterning proteins and cells on polyacrylamide gels. Soft Matter, 8(27), pp. 7197-7206.
Ahmed, W. W., T. C. Li, S. S. Rubakhin, A. Chiba, J. V. Sweedler, and T. A. Saif. (2012) Mechanical tension modulates local and global vesicle dynamics in neurons. Journal of Cellular and Molecular Bioengineering, Vol 5(2), pp 155-164.
Tang, X., P. Bajaj, R. Bashir, and M. T. A. Saif. (2011) How far cardiac cells can see each other mechanically. Soft Matter 7, 6151-6158.
Tang, X., T. B. Kuhlenschmidt, M. S. Kuhlenschmidt, and M. T. A. Saif. (2010) Mechanical force affects expression of an in vitro metastasis-like phenotype in HCT-8 cells. Biophysical Journal, Volume 99, Issue 8, 2460-2469, 20 October 2010.
Rajagopalan, J., A. Tofangchi, and M. T. A. Saif. (2010) Drosophila neurons actively regulate tension in their axons in vivo. Biophysical Journal, 99(10) pp. 3208 – 3215, 17 November 2010.
Siechen S., Yang S., Chiba A., and Saif T. (2009) Mechanical tension contributes to clustering of neurotransmitter vesicles at presynaptic terminals. PNAS 106(31), 12611-12616.