Quantification of Axonal Outgrowth on a Surface with Asymmetric Topography

ABSTRACTTopographical features are known to influence the axonal outgrowth of neurons. Understanding what kinds of topographical features are most effective at growth cone guidance and how outgrowth responds to these structures is of great importance to the study of nerve regeneration. To this end we analyze axonal outgrowth on tilted nanorod substrates which have been shown to impart directional bias to neuron growth. We utilize the Atomic Force Microscope to characterize the surface features present on these substrates and how such features are influencing the axonal outgrowth. Additionally, using a model which considers the neuronal growth cone as an object influenced by an effective potential we determine an effective force imparted on the growth cone by the surface topography.

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Use of the Atomic Force Microscope To Determine the Effect of Substratum Surface Topography on Bacterial Adhesion

Langmuir ◽

10.1021/la011142p ◽

2002 ◽

Vol 18 (6) ◽

pp. 2343-2346 ◽

Cited By ~ 103

Author(s):

R. D. Boyd ◽

J. Verran ◽

M. V. Jones ◽

M. Bhakoo

Keyword(s):

Atomic Force Microscope ◽

Surface Topography ◽

Bacterial Adhesion ◽

Atomic Force

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Contributions of lunate cells and wax crystals to the surface anisotropy of Nepenthes slippery zone

Royal Society Open Science ◽

10.1098/rsos.180766 ◽

2018 ◽

Vol 5 (9) ◽

pp. 180766 ◽

Cited By ~ 1

Author(s):

Lixin Wang ◽

Dashuai Tao ◽

Shiyun Dong ◽

Shanshan Li ◽

Yu Tian

Keyword(s):

Atomic Force Microscope ◽

Surface Topography ◽

Friction Force ◽

Body Length ◽

Structural Features ◽

Large Displacements ◽

Surface Anisotropy ◽

Atomic Force ◽

Microstructure Examination ◽

Wax Crystals

Nepenthes slippery zone presents surface anisotropy depending on its specialized structures. Herein, via macro–micro–nano scaled experiments, we analysed the contributions of lunate cells and wax crystals to this anisotropy. Macroscopic climbing of insects showed large displacements (triple body length within 3 s) and high velocities (6.16–20.47 mm s −1 ) in the inverted-fixed (towards digestive zone) slippery zone, but failed to climb forward in the normal-fixed (towards peristome) one. Friction force of insect claws sliding across inverted-fixed lunate cells was about 2.4 times of that sliding across the normal-fixed ones, whereas showed unobvious differences (1.06–1.11 times) between the inverted- and normal-fixed wax crystals. Innovative results from atomic force microscope scanning and microstructure examination demonstrated the upper layer of wax crystals causes the cantilever tip to generate rather small differences in friction data (1.92–2.72%), and the beneath layer provides slightly higher differences (4.96–7.91%). The study confirms the anisotropic configuration of lunate cells produces most of the anisotropy, whereas both surface topography and structural features of the wax crystals generate a slight contribution. These results are helpful for understanding the surface anisotropy of Nepenthes slippery zone, and guide the design of bioinspired surface with anisotropic properties.

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Rapid Impact of Progesterone on the Neuronal Growth Cone

Endocrinology ◽

10.1210/en.2013-1175 ◽

2013 ◽

Vol 154 (10) ◽

pp. 3784-3795 ◽

Cited By ~ 11

Author(s):

Laura Olbrich ◽

Lisa Wessel ◽

Ajeesh Balakrishnan-Renuka ◽

Marion Böing ◽

Beate Brand-Saberi ◽

...

Keyword(s):

Progesterone Receptor ◽

Growth Cone ◽

Progesterone Receptors ◽

Laser Scanning Microscopy ◽

Axonal Outgrowth ◽

Neuronal Growth ◽

Drg Neurons ◽

Progesterone Treatment ◽

Neuronal Growth Cone ◽

The Impact

In the last two decades, sensory neurons and Schwann cells in the dorsal root ganglia (DRG) were shown to express the rate-limiting enzyme of the steroid synthesis, cytochrome P450 side-chain cleavage enzyme (P450scc), as well as the key enzyme of progesterone synthesis, 3β-hydroxysteroid dehydrogenase (3β-HSD). Thus, it was well justified to consider that DRG neurons similarly are able to synthesize progesterone de novo from cholesterol. Because direct progesterone effects on axonal outgrowth in peripheral neurons have not been investigated up to now, the present study provides the first insights into the impact of exogenous progesterone on axonal outgrowth in DRG neurons. Our studies including microinjection and laser scanning microscopy demonstrate morphological changes especially in the neuronal growth cones after progesterone treatment. Furthermore, we were able to detect a distinctly enhanced motility only a few minutes after the start of progesterone treatment using time-lapse imaging. Investigation of the cytoskeletal distribution in the neuronal growth cone before, during, and after progesterone incubation revealed a rapid reorganization of actin filaments. To get a closer idea of the underlying receptor mechanisms, we further studied the expression of progesterone receptors in DRG neurons using RT-PCR and immunohistochemistry. Thus, we could demonstrate for the first time that classical progesterone receptor (PR) A and B and the recently described progesterone receptor membrane component 1 (PGRMC1) are expressed in DRG neurons. Antagonism of the classical progesterone receptors by mifepristone revealed that the observed progesterone effects are transmitted through PR-A and PR-B.

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The Effect of an Electrostatic Force on Imaging a Surface Topography by Noncontact Atomic Force Microscope

Japanese Journal of Applied Physics ◽

10.1143/jjap.40.l986 ◽

2001 ◽

Vol 40 (Part 2, No. 9A/B) ◽

pp. L986-L988 ◽

Cited By ~ 11

Author(s):

Tadashi Shiota ◽

Keiji Nakayama

Keyword(s):

Atomic Force Microscope ◽

Surface Topography ◽

Electrostatic Force ◽

Atomic Force

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Atomic Force and Ultrasonic Force Microscopic Surface Characterization of Laser Treated Head Sliders

10.1115/imece2001/nde-25806 ◽

2001 ◽

Author(s):

Carl Druffner ◽

Edward J. Schumaker ◽

Liming Shen ◽

Shamachary Sathish ◽

Ganesh N. Raikar ◽

...

Keyword(s):

Atomic Force Microscope ◽

Surface Topography ◽

Surface Characterization ◽

Atomic Force ◽

Hard Disc Drive ◽

Microscope Imaging ◽

Disc Drive ◽

Microscopic Surface

Abstract The surface of laser treated hard disc drive head sliders has been imaged using the Atomic Force Microscope and Ultrasonic Force Microscope. The contrast of the surface topography image from the Atomic Force Microscope is compared with the elasticity image generated by the Ultrasonic Force Microscope on the same sample region. Images of microcracking in the laser treated regions are presented. The possible reasons for the development of microcracking and the enhanced contrast of the Ultrasonic Force Microscope imaging of these microcracks are discussed.

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