Variation in Young's modulus along the length of a rat vibrissa.

J Biomech

Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA.

Published: November 2011

Rats use specialized tactile hairs on their snout, called vibrissae (whiskers), to explore their surroundings. Vibrissae have no sensors along their length, but instead transmit mechanical information to receptors embedded in the follicle at the vibrissa base. The transmission of mechanical information along the vibrissa, and thus the tactile information ultimately received by the nervous system, depends critically on the mechanical properties of the vibrissa. In particular, transmission depends on the bending stiffness of the vibrissa, defined as the product of the area moment of inertia and Young's modulus. To date, Young's modulus of the rat vibrissa has not been measured in a uniaxial tensile test. We performed tensile tests on 22 vibrissae cut into two halves: a tip-segment and a base-segment. The average Young's modulus across all segments was 3.34±1.48GPa. The average modulus of a tip-segment was 3.96±1.60GPa, and the average modulus of a base-segment was 2.90±1.25GPa. Thus, on average, tip-segments had a higher Young's modulus than base-segments. High-resolution images of vibrissae were taken to seek structural correlates of this trend. The fraction of the cross-sectional area occupied by the vibrissa cuticle was found to increase along the vibrissa length, and may be responsible for the increase in Young's modulus near the tip.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jbiomech.2011.08.027DOI Listing

Publication Analysis

Top Keywords

young's modulus
24
modulus
8
vibrissa
8
rat vibrissa
8
average modulus
8
young's
5
variation young's
4
modulus length
4
length rat
4
vibrissa rats
4

Similar Publications

To analyze the motion laws of a magnetic and elastic coupling system under the influence of various factors, this paper proposes a magnetic coupling pendulum based on spring pieces and magnets-a magnetic-mechanical oscillator. By fixing spring pieces onto two non-magnetic bases and attaching magnets to their upper ends, which repel each other, the potential energy during oscillation is expanded using Fourier series. Subsequently, Lagrange equations are solved to study the effects of the first two terms of potential energy.

View Article and Find Full Text PDF

Gelatin is a versatile substance extensively used in medical and pharmaceutical industries for many applications, including capsule shells, X-ray film, infusion for plasma substitute, and the fabricating of artificial tissue. Fish scale gelatin is a profitable alternative source as a halal material despite its inferior quality. An addition of phenolic cross-linker may enhance the qualities of fish scale gelatin.

View Article and Find Full Text PDF

Optical fibers are between the most common implantable devices for delivering light in the nervous system for optogenetics and infrared neural stimulation applications. Tapered optical fibers, in particular, can offer homogeneous light delivery to a large volume and spatially resolved illumination compared to standard flat-cleaved fibers while being minimally invasive. However, the use of tapers for neural applications has up to now been limited to silica optical fibers, whose large Young's modulus can cause detrimental foreign body response in chronic settings.

View Article and Find Full Text PDF

Biomimetic bone cartilage scaffolds based on trilayer methacrylated hydroxyapatite/GelMA composites for full-thickness osteochondral regeneration.

Int J Biol Macromol

January 2025

Department of Pharmaceutical Analysis, Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, The School of Pharmacy, Fujian Medical University, Fuzhou 350122, China. Electronic address:

Since cartilage injury is often accompanied by subchondral bone damage, conventional single-phase materials cannot accurately simulate the osteochondral structure or repair osteochondral injury. In this work, a gradient gelatin-methacryloyl (GelMA) hydrogel scaffold was constructed by a layer-by-layer stacking method to realize full-thickness regeneration of cartilage, calcified cartilage and subchondral bone. Of note, to surmount the inadequate mechanical property of GelMA hydrogel, nanohydroxyapatite (nHA) was incorporated and further functionalized with hydroxyethyl methacrylate (nHA-hydroxyethyl methacrylate, nHAMA) to enhance the interfacial adhesion with the hydrogel, resulting in better mechanical strength akin to human bone.

View Article and Find Full Text PDF

Purpose: To evaluate the posterior scleral stiffness of different regions in high myopic eyes and to explore its associations with macular choroidal and peripapillary retinal nerve fiber layer (pRNFL) thickness and vasculature.

Methods: Thirty subjects with high myopic eyes and 30 subjects with low myopic eyes were included in this study. The elastic modulus of the macular and peripapillary sclera at the temporal, nasal, superior and inferior regions were determined via shear wave elastography (SWE).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!