Purpose: To examine neuronal activation in the spinal cord due to secondary hyperalgesia resulting from intrajoint capsaicin injection, and the effect of physiotherapy manipulation, using functional magnetic resonance imaging (fMRI), in ␣-chloralose anesthetized rats. Materials and Methods:FMRI of the rat lumbar spinal cord was performed at 9.4 Tesla. Stimuli included injection of 25 L of capsaicin (128 g/mL in 7.5% dimethyl sulfoxide [DMSO]) into the right forepaw or 75 L into the right ankle joint followed by a light touch stimulus, with and without physiotherapy manipulation.Results: Activation of pain areas of the spinal cord (dorsal horn) was found in all animals after injection of capsaicin into the plantar surface of the rat hindpaw and ankle joint. Overlay maps depicting activations and deactivations showed significant reproducibility between experiments. Greater overlay of activations were observed for intrajoint compared to intradermal capsaicin injection. The distribution of activations after stimulation of the hindpaw using a light touch stimulus was somewhat more varied; activation of the dorsal horn was evident, with greater overlap resulting when joint mobilization was not performed. Conclusion:Results suggest a trend toward decreased areas of activation in the spinal cord associated with pain, as a result of hyperalgesia, following physiotherapy joint mobilization. JOINT MOBILIZATION AND MANIPULATION has been used by physiotherapists and other practitioners for many years to manage painful musculoskeletal disorders. It appears that these treatments can exert a painrelieving effect and contribute to improved function in patients with neck and back pain (1-4).The mechanism of pain relief remains the subject of ongoing investigations. It has been suggested that activation of segmental pain inhibitory mechanisms and descending pain inhibitory systems projecting from brain to spinal cord might be important for mediating manipulation-induced analgesia in the period immediately after treatment application (5).The results of multiple studies clearly demonstrate that mobilization of the cervical spine induces an immediate-onset hypoalgesic or antihyperalgesic effect in patients with lateral epicondylalgia; patients with insidious cervical joint pain; and in pain-free, normal volunteers (6 -10). A consistent observation has been that application of joint mobilization treatments produces a significant elevation of pressure pain thresholds and other measures of mechanical hyperalgesia, but that these treatments have absolutely no influence on thermal pain measures. As well as influencing pain related measures, joint mobilization techniques also produce changes in measures related to motor function and autonomic nervous system function (6,8). A strong correlation between changes in pain-related measures and changes in autonomic nervous system-related measures have been demonstrated. Sluka and Wright (11) provided evidence of an antihyperalgesic effect of peripheral joint mobilization in the rat, using an intr...

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Cy5.5‐lectin, a non‐toxic conjugate, combines the benefits of near‐infrared (NIR) imaging, such as significant reduction of background fluorescence and increased tissue depth penetration, with its affinity for vascular endothelial cells. When compared to endothelial staining methods using FITC‐lectin and ICAM2 antibodies, Cy5.5‐lectin was confirmed to specifically bind endothelial cells and produce a fluorescence signal both in real‐time and post‐infusion. Ex‐vivo experiments with isolated hearts demonstrated that binding was limited to perfused areas of the myocardium. With mouse in‐vivo tail‐vein injections, other organs such as the liver, spleen, and kidney were also stained and yielded similar quality images of the heart. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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