Cerebral activation by the signals ascending through unmyelinated C-fibers in humans: a magnetoencephalographic study

Tran, Tuan Diep; Inui, Koji; Hoshiyama, Minoru; Lam, Khanh; Qiu, Yunhai; Kakigi, Ryusuke

doi:10.1016/s0306-4522(02)00195-1

Cited by 58 publications

(29 citation statements)

References 44 publications

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“…Activation in the primary somatosensory cortex following A and C fiber activation is still a matter of controversy [17][18][19]. By contrast, a clear difference was found using fMRI [20].…”

Section: Discussionmentioning

confidence: 99%

Tobacco Smoking Can Potentiate C-fiber Evoked Potentials in Human Brain

Miyazaki¹,

Wang²,

Inui³

et al. 2009

TOPAINJ

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Abstract:The effects of smoking and nicotine on ultralate laser evoked potentials (LEPs), the EEG responses to C-fiber stimulation by a laser beam, were investigated in humans. Ultralate LEPs were repeatedly measured in two sessions, one after smoking, and the other in abstinence from smoking. The dominant frequency of the background EEG alpha activity, heart rate and venous plasma nicotine concentration were also measured. The peak-to-peak amplitude of the two major components (N2 and P2) of ultralate LEPs was significantly correlated both with the plasma nicotine concentration and with the background alpha frequency. The results suggest an arousal effect of nicotine on C-fiber mediated pain. The effect of nicotine on C-fiber LEPs was in the opposite direction of that on A fiber LEPs. The difference between C and A fibers might indicate a difference in effects of nicotine on first and second pain responses.

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“…Activation in the primary somatosensory cortex following A and C fiber activation is still a matter of controversy [17][18][19]. By contrast, a clear difference was found using fMRI [20].…”

Section: Discussionmentioning

confidence: 99%

Tobacco Smoking Can Potentiate C-fiber Evoked Potentials in Human Brain

Miyazaki¹,

Wang²,

Inui³

et al. 2009

TOPAINJ

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“…Laser beams applied to a tiny area [4,7,9,28,31,35] have been used to selectively activate C fibers, which is considered difficult to do with electrical stimulation, since C fibers generally have a high threshold to electrical stimulation. However, the present results indicate that this threshold is not so high when appropriate parameters are chosen.…”

Section: Discussionmentioning

confidence: 99%

“…Various techniques (for review, see [1]) have been used to investigate C fiber-related cerebral processing [2][3][4][5][6][7][8] as well as conduction velocity (CV) [9], each with its own strengths and weaknesses.…”

Section: Introductionmentioning

confidence: 99%

Selective Stimulation of C Fibers by an Intra-Epidermal Needle Electrode in Humans

Otsuru

Inui²,

Yamashiro³

et al. 2009

TOPAINJ

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Abstract:We recorded evoked potentials (EPs) induced by intra-epidermal electrical stimulation using a needle electrode with specific parameters. We identified the fibers activated by this specific stimulation by assessing the conduction velocity (CV) of the peripheral nerve. The EPs were recorded from the Cz electrode (vertex) of the International 10-20 system in ten healthy male subjects. The dorsum of the left hand and forearm were stimulated with an intensity of 0.01 mA above the sensory threshold. The mean P1 latency of EPs for the hand and forearm were 1007 ± 88 and 783 ± 80 ms, respectively, and the CV estimated from the latency of P1 was 1.5 ± 0.7 m/s. The CV indicated that the fibers activated by the stimulation were C fibers. Since the method of stimulation is convenient and non-invasive, it should be useful for investigating the functions of small fibers.

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“…The parietal operculum (SII) rather than the anterior insula was found to be involved with raised heat pain thresholds in 6 stroke patients with involvement of SII and/or anterior insula [22], while a patient with a tumour involving the parietal operculum and posterior insula (subsequently removed) had interference with both mechanical and thermal pain sensations [23]. The ipsi- and contralateral parietal opercula were shown to be activated by unspecified painful stimuli [24, 25], a finding endorsed by others; in view of this, it must be emphasized that when CPSP occurs as a result of an SII-insular lesion, the symptoms are always contralateral to the damage. Painful stimuli were shown to activate the opercular (SII) cortex and insula sequentially [26], with a delay of about 50 ms. Jones et al [27] have recently shown that there is a reduction in opioid receptor binding in the insula of patients with central neuropathic pain.…”

Section: Discussionmentioning

confidence: 99%

Somatic Sensation and the Insular-Opercular Cortex: Relationship to Central Pain

Bowsher

2006

Eur Neurol

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We report 5 stroke patients with lesions affecting the insula and parietal operculum sparing the postcentral gyrus (somatosensory cortical area SI); 3 had spontaneous central poststroke pain (CPSP) and 2 did not. All were imaged and underwent quantitative sensory threshold tests, though not all modalities were tested in all subjects. Tactile thresholds were unaltered in all. The patients with CPSP exhibited greatly elevated thresholds for mechanical pain (skinfold pinch), sharpness and thermal sensations; the pain-free patients had distinctly lesser elevations of their skinfold pinch and innocuous and noxious thermal thresholds, and no sharpness deficit. It is therefore suggested that, in the case of similar cortical lesions, the presence or absence of spontaneous pain either modifies the thresholds for some innocuous modalities, or that the degree of deficit of some innocuous modalities determines whether or not central pain occurs.

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Cerebral activation by the signals ascending through unmyelinated C-fibers in humans: a magnetoencephalographic study

Cited by 58 publications

References 44 publications

Tobacco Smoking Can Potentiate C-fiber Evoked Potentials in Human Brain

Tobacco Smoking Can Potentiate C-fiber Evoked Potentials in Human Brain

Selective Stimulation of C Fibers by an Intra-Epidermal Needle Electrode in Humans

Somatic Sensation and the Insular-Opercular Cortex: Relationship to Central Pain

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