Functional magnetic resonance imaging (fMRI) is increasingly being used for animal studies studying the transmission of nociceptive information. Application of noxious mechanical stimuli is widely used for animal and human assessment of pain processing. Any accessory hardware used in animal imaging studies must, however, be sufficiently small to fit in the magnet bore diameter and be non-magnetic. We have developed a system that can apply mechanical stimuli simultaneously with fMRI. This system consists of a standardized instrument to deliver mechanical stimuli (VonFrey monofilament) and a gas-pressured mechanical transducer. These components were integrated with a computer console that controlled the period of stimuli to match acquisition scans. Preliminary experiments demonstrated that the force-stimulus transducer did not influence MRI signal to noise ratio. Mechanical stimulation of the hindpaw significantly increased blood oxygen level dependent (BOLD) signal intensity in several midbrain regions involved in the processing of nociceptive information in the rat (p<0.001, uncorrected for multiple comparisons). This system can be applied to both animal and human imaging studies and has a wide range of applications for studies of nociceptive processing.
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http://dx.doi.org/10.1016/j.jneumeth.2007.02.006 | DOI Listing |
Trends Biotechnol
January 2025
State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310058, People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China. Electronic address:
Replicating the contractile function of arterial tissues in vitro requires precise control of cell alignment within 3D structures, a challenge that existing bioprinting techniques struggle to meet. In this study, we introduce the voxel-based embedded construction for tailored orientational replication (VECTOR) method, a voxel-based approach that controls cellular orientation and collective behavior within bioprinted filaments. By fine-tuning voxel vector magnitude and using an omnidirectional printing trajectory, we achieve structural mimicry at both the macroscale and the cellular alignment level.
View Article and Find Full Text PDFOcul Surf
January 2025
Department of Physiology, Showa University Graduate School of Medicine, 1-5-8 Hatanodai, Shinagawa, Tokyo 142-8555, Japan.
Purpose: Mechanical stress on the ocular surface, such as from eye-rubbing, has been reported to lead to inflammation and various ocular conditions. We hypothesized that the mechanosensitive Piezo1 channel in the conjunctival epithelium contributes to the inflammatory response at the ocular surface after receiving mechanical stimuli.
Methods: Human conjunctival epithelial cells (HConjECs) were treated with Yoda1, a Piezo1-specific agonist, and various allergens to measure cytokine expression levels using qRT-PCR.
Arch Oral Biol
January 2025
Department of Dentistry-Orthodontics and Craniofacial Biology, Research Institute for Medical Innovation, Radboud university medical center, Philips van Leydenlaan 25, Nijmegen 6525 EX, the Netherlands. Electronic address:
Objectives: To investigate in vivo whether myofibroblasts formed in the PDL after exposure to short-term high experimental orthodontic forces in rats survive. To study in vitro whether human PDL fibroblasts can differentiate into myofibroblasts and survive when chemical or mechanical stimuli are removed.
Design: Nine 6-week-old male Wistar rats were used in this experiment.
Front Syst Neurosci
December 2024
Universidade Federal de Goias, School of Electrical, Mechanical and Computer Engineering, Goiânia, Brazil.
Dysfunction in fear and stress responses is intrinsically linked to various neurological diseases, including anxiety disorders, depression, and Post-Traumatic Stress Disorder. Previous studies using in vivo models with Immediate-Extinction Deficit (IED) and Stress Enhanced Fear Learning (SEFL) protocols have provided valuable insights into these mechanisms and aided the development of new therapeutic approaches. However, assessing these dysfunctions in animal subjects using IED and SEFL protocols can cause significant pain and suffering.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
Organic room-temperature phosphorescence (RTP) emitters with long lifetimes, high exciton utilizations, and tunable emission properties show promising applications in organic light-emitting diodes (OLEDs) and biomedical fields. Their excited-state properties are highly related to single molecular structure, aggregation morphology, and external stimulus (such as hydrostatic pressure effect). To gain a deeper understanding and effectively regulate the key factors of luminescent efficiency and lifetime for RTP emitters, we employ the thermal vibration correlation function (TVCF) theory coupled with quantum mechanics/molecular mechanics (QM/MM) calculations to investigate the photophysical properties of three reported RTP crystals (Bp-OEt, Xan-OEt, and Xan-OMe) with elastic/plastic deformation.
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