Activation of ipsilateral primary sensorimotor cortex by median nerve stimulation

Korvenoja, Antti; Wikström, Heidi; Huttunen, J.; Virtanan, J; Laine, Pauli; Hj, Aronen; Am, Seppäläinen; Ilmoniemi, Risto J.

doi:10.1097/00001756-199512150-00033

Cited by 70 publications

(46 citation statements)

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“…The above-described modulatory effect of ipsilateral input on the SI response to stimulation of the contralateral hand, together with (1) reports by others of neurons with ipsilateral receptive fields in SI of nonhuman primates (for review, see Iwamura et al, 2002), (2) demonstrations of short-latency activation of human SI in response to electrical stimulation of the ipsilateral median nerve (Allison et al, 1989a(Allison et al, ,b, 1992Korvenoja et al, 1995;Nihashi et al, 2005), and (3) the recent discovery that unilaterally applied flutter stimulation of the hand evokes short-latency neuromagnetic activity in both the contralateral and ipsilateral SI of conscious humans (Tan et al, 2004), demonstrates not only that the SI hand representational region receives substantial ipsilateral input but, in addition, shows that ipsilateral input evoked by gentle mechanical skin stimulation can alter the SI response to contralateral flutter stimulation.…”

Section: Discussionmentioning

confidence: 90%

“…Additionally, imaging and neurophysiological studies (in monkeys, Iwamura et al, 2001;Lipton et al, 2006;in humans, Allison et al, 1989a,b;Korvenoja et al, 1995;Nihashi et al, 2005;Hlushchuk et al, 2006) described modifications of SI (area 3b) activity in response to input evoked by either mechanical stimulation of an ipsilateral skin site or electrical stimulation of an ipsilateral peripheral nerve. Human investigations have shown that ipsilateral input can modify the SI response to a subsequent contralateral stimulus.…”

Section: Introductionmentioning

confidence: 99%

“…Schnitzler et al (1995), using magnetoencephalography (MEG), reported that concurrent tactile stimulation of the ipsilateral hand enhances the response of SI to stimulation of the contralateral median nerve. Conversely, (1) Korvenoja et al (1995) reported that the SI activation (detected using MEG) evoked by contralateral median nerve stimulation is suppressed during ipsilateral hand movement, (2) functional magnetic resonance imaging studies in both monkeys (Lipton et al, 2006) and humans (Hlushchuk et al, 2006) showed that an ipsilateral skin stimulus evokes CNS actions that partially suppress the SI response to a contralateral stimulus, (3) destruction of SI in one hemisphere (rats) was shown to be accompanied by the appearance (in the opposite SI) of neurons with bilateral receptive fields [interpreted to indicate that SI activity exerts a suppressive influence on SI neurons in the opposite hemisphere (Pluto et al, 2005)], and (4) low-frequency transcranial magnetic stimulation of sensorimotor cortex (in humans, Pal et al, 2005) was found to reduce excitability in the opposite hemisphere. Viewed collectively, these findings raise the possibility that the response of the SI hand region to a tactile stimulus (and thus the stimulus-evoked perceptual experience) may be subject to modulatory influences arising from the ipsilateral hand.…”

Section: Introductionmentioning

confidence: 99%

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Ipsilateral Input Modifies the Primary Somatosensory Cortex Response to Contralateral Skin Flutter

Tommerdahl

Simons²,

Chiu³

et al. 2006

J. Neurosci.

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We recorded the optical intrinsic signal response of squirrel monkey primary somatosensory cortex (SI) to 25 Hz vibrotactile ("flutter") stimulation applied independently to the thenar eminence on each hand and also to bilateral (simultaneous) stimulation of both thenars. The following observations were obtained in every subject (n ϭ 5). (1) Ipsilateral stimulation was accompanied by an increase in absorbance within the SI hand region substantially smaller than the absorbance increase evoked by contralateral stimulation. (2) The absorbance increase evoked by simultaneous bilateral stimulation was smaller (by ϳ30%) than that evoked by contralateral stimulation. (3) The spatiointensive pattern of the SI response to bilateral flutter was distinctly different than the pattern that accompanied contralateral flutter stimulation: with contralateral flutter, the center of the responding region of SI underwent a large increase in absorbance, whereas absorbance decreased in the surrounding region; in contrast, during bilateral flutter, absorbance decreased (relative to that evoked by contralateral flutter) in the central region of SI but increased in the surround. The results raise the possibility that somatosensory perceptual experiences specific to bimanual tactile object exploration derive, at least in part, from the unique spatiointensive activity pattern evoked in SI when the stimulus makes contact with both hands. It is suggested that modulatory influences evoked by ipsilateral thenar flutter stimulation reach SI via a two-stage pathway involving interhemispheric (callosal) connections between information processing levels higher than SI and subsequently via intrahemispheric (corticocortical) projections to the SI hand region.

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Section: Discussionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ipsilateral Input Modifies the Primary Somatosensory Cortex Response to Contralateral Skin Flutter

Tommerdahl

Simons²,

Chiu³

et al. 2006

J. Neurosci.

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“…The reliability of localization of short-latency activity at the contralateral SI has been verified by superimposition of the calculated source coordinates on individual magnetic resonance images (MRIs) [e.g., Yang et al, 1993]. Recent studies have suggested that somatosensory evoked magnetic fields (SEFs) also get significant contributions from the contralateral parietal cortex posterior to area 3b [Forss et al, 1994], the ipsilateral SI [Korvenoja et al, 1995], and the wall of the interhemispheric fissure [Forss et al, 1996]. Studies using realistic head models and the signal-space-projection method [Uusitalo and Ilmoniemi, 1997] have suggested that even SEFs arising at the cerebellum can be identified [Tesche and Karhu, 1997].…”

Section: Introductionmentioning

confidence: 97%

Activation of multiple cortical areas in response to somatosensory stimulation: Combined magnetoencephalographic and functional magnetic resonance imaging

et al. 1999

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We combined information from functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) to assess which cortical areas and in which temporal order show macroscopic activation after right median nerve stimulation. Five healthy subjects were studied with the two imaging modalities, which both revealed significant activation in the contra- and ipsilateral primary somatosensory cortex (SI), the contra- and ipsilateral opercular areas, the walls of the contralateral postcentral sulcus (PoCS), and the contralateral supplementary motor area (SMA). In fMRI, two separate foci of activation in the opercular cortex were discerned, one posteriorly in the parietal operculum (PO), and one anteriorly near the insula or frontal operculum (anterior operculum, AO). The activation sites from fMRI were used to constrain the solution of the inverse problem of MEG, which allowed us to construct a model of the temporal sequence of activation of the different sites. According to this model, the mean onset latency for significant activation at the contralateral SI was 20 msec (range, 17-22 msec), followed by activation of PoCS at 23 msec (range, 21-25 msec). The contralateral PO was activated at 26 msec (range, 19-32 msec) and AO at 33 msec (range, 22-51 msec). The contralateral SMA became active at 36 msec (range, 24-48 msec). The ipsilateral SI, PO, and AO became activated at 54-67 msec. We conclude that fMRI provides a useful means to constrain the inverse problem of MEG, allowing the construction of spatiotemporal models of cortical activation, which may have significant implications for the understanding of cortical network functioning.

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“…In magnetoencephalographic recordings, long-latency (90 -300 ms) responses have been reported in the ipsilateral SI region to electric median nerve stimuli in healthy adults (Korvenoja et al, 1995(Korvenoja et al, , 1999. However, such findings are rare: only 13 of 401 neurological patients and only 1 of 81 healthy subjects showed ipsilateral responses to median nerve stimulation at area 3b of SI (Kanno et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Transient Suppression of Ipsilateral Primary Somatosensory Cortex during Tactile Finger Stimulation

Hlushchuk¹,

Hari²

2006

J. Neurosci.

218

217

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The whole human primary somatosensory (SI) cortex is activated by contralateral tactile stimuli, whereas its subarea 2 displays neuronal responses also to ipsilateral stimuli. Here we report on a transient deactivation of area 3b of the ipsilateral SI during long-lasting tactile stimulation.We collected functional magnetic resonance imaging data witha3Tscanner from 10 healthy adult subjects while tactile pulses were delivered at 1, 4, or 10 Hz in 25 s blocks to three right-hand fingers. In the contralateral SI cortex, activation [positive blood oxygenation level-dependent (BOLD) response] outlasted the stimulus blocks by 20 s, with an average duration of 45 s. In contrast, a transient deactivation (negative BOLD response) occurred in the ipsilateral rolandic cortex with an average duration of 18 s. Additional recordings on 10 subjects confirmed that the deactivation was not limited to the right SI but occurred in the SI cortex ipsilateral to the stimulated hand. Moreover, the primary motor cortex (MI) contained voxels that were phasically deactivated in response to both ipsilateral and contralateral touch.These data indicate that unilateral touch of fingers is associated, in addition to the well known activation of the contralateral SI cortex, with deactivation of the ipsilateral SI cortex and of the MI cortex of both hemispheres. The ipsilateral SI deactivation could result from transcallosal inhibition, whereas intracortical SI-MI connections could be responsible for the MI deactivation. The shorter time course of deactivation than activation would agree with stronger decay of inhibitory than EPSP at the applied stimulus repetition rates.

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Activation of ipsilateral primary sensorimotor cortex by median nerve stimulation

Cited by 70 publications

References 0 publications

Ipsilateral Input Modifies the Primary Somatosensory Cortex Response to Contralateral Skin Flutter

Ipsilateral Input Modifies the Primary Somatosensory Cortex Response to Contralateral Skin Flutter

Activation of multiple cortical areas in response to somatosensory stimulation: Combined magnetoencephalographic and functional magnetic resonance imaging

Transient Suppression of Ipsilateral Primary Somatosensory Cortex during Tactile Finger Stimulation

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