TY - JOUR
T1 - Drosophila neurons actively regulate axonal tension in vivo
AU - Jagannathan Rajagopalan, Rajagopalan
AU - Alireza Tofangchi, Tofangchi
AU - Saif, M. Taher A.
N1 - Funding Information:
This work was supported by the National Institutes of Health (NINDS NS063405-01) and the National Science Foundation (ECS 05-24675, CMMI 0800870, and ECCS 0801928). The force sensors were fabricated in the Micro-Nano-Mechanical Systems Cleanroom at the University of Illinois at Urbana-Champaign.
PY - 2010/11/17
Y1 - 2010/11/17
N2 - Several experiments have shown that mechanical forces significantly influence the initiation, growth, and retraction of neurites of cultured neurons. A similar role has long been suggested for mechanical forces in vivo, but this hypothesis has remained unverified due to the paucity of in vivo studies of neuronal mechanical behavior. In this study, we used high-resolution micromechanical force sensors to study the mechanical response of motor neurons in live Drosophila embryos. Our experiments showed that Drosophila neurons maintained a rest tension (1- 13 nN) and behaved like viscoelastic solids (i.e., with a linear force-deformation response followed by force relaxation to steady state) in response to sustained stretching. More importantly, when the tension was suddenly diminished by a release of the externally applied force, the neurons contracted and actively generated force to restore tension, sometimes to a value close to their rest tension. In addition, axons that were slackened by displacing the neuromuscular junction contracted and became taut in 10- 30 min. These observations are remarkably similar to results from in vitro studies and suggest that mechanical tension may also strongly influence neuronal behavior in vivo.
AB - Several experiments have shown that mechanical forces significantly influence the initiation, growth, and retraction of neurites of cultured neurons. A similar role has long been suggested for mechanical forces in vivo, but this hypothesis has remained unverified due to the paucity of in vivo studies of neuronal mechanical behavior. In this study, we used high-resolution micromechanical force sensors to study the mechanical response of motor neurons in live Drosophila embryos. Our experiments showed that Drosophila neurons maintained a rest tension (1- 13 nN) and behaved like viscoelastic solids (i.e., with a linear force-deformation response followed by force relaxation to steady state) in response to sustained stretching. More importantly, when the tension was suddenly diminished by a release of the externally applied force, the neurons contracted and actively generated force to restore tension, sometimes to a value close to their rest tension. In addition, axons that were slackened by displacing the neuromuscular junction contracted and became taut in 10- 30 min. These observations are remarkably similar to results from in vitro studies and suggest that mechanical tension may also strongly influence neuronal behavior in vivo.
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U2 - 10.1016/j.bpj.2010.09.029
DO - 10.1016/j.bpj.2010.09.029
M3 - Article
C2 - 21081068
AN - SCOPUS:78649285851
SN - 0006-3495
VL - 99
SP - 3208
EP - 3215
JO - Biophysical journal
JF - Biophysical journal
IS - 10
ER -