title: Validation of an automated punctate mechanical stimuli delivery system designed for fMRI studies in rodents.
abstract: 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.
authors: School of Biomedical Sciences, University of Nottingham, Nottingham NG7 2UH, UK. rgoverno@fmrib.ox.ac.uk
authors: Ricardo Jose Moylan
authors: RJ
authors: Governo
authors: Malcolm John William
authors: MJ
authors: Prior
authors: Peter Gordon
authors: PG
authors: Morris
authors: Charles Alexander
authors: CA
authors: Marsden
authors: Victoria
authors: V
authors: Chapman
mesh_terms: D000818:Animals; D001921:Brain / Q000098:blood supply*; D001931:Brain Mapping; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010147:Pain Measurement; D010812:Physical Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D010100:Oxygen