The effects of confinement on neuronal growth cone morphology and velocity.
Optimizing growth cone guidance through the use of patterned substrates is important for designing regenerative substrates to aid in recovery from neuronal injury. Using laser ablation, we designed micron-scale patterns capable of confining dissociated mouse cerebellar granule neuron growth cones to channels of different widths ranging from 1.5 to 12 μm. Growth cone dynamics in these channels were observed using time-lapse microscopy. Growth cone area was decreased in channels between 1.5 and 6 μm as compared to that in 12 μm and unpatterned substrates. Growth cone aspect ratio was also affected as narrower channels forced growth cones into a narrow, elongated shape. There was no difference in the overall rate of growth cone advance in uniform channels between 1.5 and 12 μm as compared to growth on unpatterned substrates. The percentage of time growth cones advanced, paused, and retracted was also similar. However, growth cones did respond to changes in confinement: growth cones in narrow lanes rapidly sped up when encountering a wide region and then slowed down as they entered another narrow region. Our results suggest that the rate of neurite extension is not affected by the degree of confinement, but does respond to changes in confinement.
Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC 20057, USA; Department of Physics and the Institute for Soft Matter Synthesis and Metrology, Georgetown University, 320 Regents Hall, Washington, DC 20057, USA.
Michael S
MS
Smirnov
Developmental Neurobiology Section, Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Katelyn A
KA
Cabral
Developmental Neurobiology Section, Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Herbert M
HM
Geller
Department of Physics and the Institute for Soft Matter Synthesis and Metrology, Georgetown University, 320 Regents Hall, Washington, DC 20057, USA. Electronic address: urbach@physics.georgetown.edu.
Jeffrey S
JS
Urbach
D000818:Animals; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D020439:Growth Cones / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D007797:Laminin / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009416:Nerve Regeneration / Q000502:physiology*; D055495:Neurogenesis / Q000502:physiology; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*
D020099:Coated Materials, Biocompatible; D007797:Laminin
Laminin; Laser ablation; Nerve regeneration; Neural cell; Polyvinylalcohol