Neuroscience research
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Neuroscience research · Mar 2015
Motor imagery of voluntary muscle relaxation induces temporal reduction of corticospinal excitability.
Voluntary muscle relaxation is an "active process" requiring cortical activation. However, cortical activation during motor imagery of muscle relaxation has not been well understood. The purpose of this study was to clarify time-dependent changes in corticospinal excitability during the imagery of muscle relaxation. ⋯ Motor evoked potentials (MEPs) were recorded from the right hand and forearm muscles. The MEP amplitudes of the FDI and the synergist temporally decreased after the auditory cue as compared with those present in the resting condition. Our finding indicates that motor imagery of muscle relaxation induces a temporal reduction of the corticospinal excitability related to the targeted muscle.
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Neuroscience research · Mar 2015
Effect of protons on the mechanical response of rat muscle nociceptive fibers and neurons in vitro.
Strong exercise makes muscle acidic, and painful. The stimulus that activates muscle nociceptors in such instance may be protons. Reportedly, however, not many afferents are excited by protons alone. ⋯ Their response magnitude was increased by both pH 6.2 and pH 6.8; in addition the mechanical threshold was lowered by pH 6.2. Decrease in the threshold by pH6.2 was also observed in MA currents. Presently observed sensitization by protons could be involved in several types of ischemic muscle pain, and may also be involved in cardiovascular and respiratory controls during exercise.