Journal of neuroscience methods
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J. Neurosci. Methods · May 2009
Spinal reflex in human lower leg muscles evoked by transcutaneous spinal cord stimulation.
The H-reflex is one of the most common and useful techniques in the field of motor control. However, the H-reflex technique also involves difficulty in data interpretation when stimulus intensity is high enough to stimulate both sensory and motor fibers (antidromic current). On the other hand, transcutaneous stimulation applied on the spinous processes is able to stimulate the dorsal root, resulting in selective stimulation of only sensory fibers without evoking a direct motor response and antidromic current on the motor fibers. ⋯ Although not significant, H(max) amplitude in SOL by SS (76%) was also greater than that by PS (60%). It is suggested that transcutaneous stimulation is able to evoke H-reflex without a direct motor response. H(max) amplitudes traditionally measured by stimulation applied to a mixed nerve may underestimate the potential connectivity between the sensory and motor systems in humans.
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The reactive tissue response of the brain to chronically implanted materials remains a formidable obstacle to stable recording from implanted microelectrodes. One approach to mitigate this response is to apply a bioactive coating in the form of an ultra-porous silica sol-gel, which can be engineered to improve biocompatibility and to enable local drug delivery. The first step in establishing the feasibility of such a coating is to investigate the effects of the coating on electrode properties. ⋯ The voltammograms revealed a slight increase in charge carrying capacity of the electrodes following coating. Impedance spectrograms showed a mild increase in impedance at high frequencies but a more pronounced decrease in impedance at mid to low frequencies. These results demonstrate the feasibility of applying silica sol-gel coatings to silicon-based microelectrodes and are encouraging for the continued investigation of their use in mitigating the reactive tissue response.
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J. Neurosci. Methods · May 2009
The use of motion analysis to measure pain-related behaviour in a rat model of degenerative tendon injuries.
Chronic tendinopathy is characterized with longstanding activity-related pain with degenerative tendon injuries. An objective tool to measure painful responses in animal models is essential for the development of effective treatment for tendinopathy. Gait analysis has been developed to monitor the inflammatory pain in small animals. ⋯ The change in double stance duration in the collagenase-treated rats was reversible by administration of buprenorphrine (p=0.029), it suggested that the detected gait changes were associated with pain. Comparisons of end-point and follow-up studies revealed the confounding effects of training, which led to higher gait velocities and probably a different adaptive response to tendon pain in the trained rats. The results showed that motion analysis could be used to measure activity-related chronic tendon pain.