Somatosensory-motor cortex interactions measured using dual-site transcranial magnetic stimulation.
Brain Stimul
; 12(5): 1229-1243, 2019.
Article
en En
| MEDLINE
| ID: mdl-31043330
ABSTRACT
BACKGROUND:
Dual-site transcranial magnetic stimulation (ds-TMS) is a neurophysiological technique to measure functional connectivity between cortical areas. OBJECTIVE/HYPOTHESIS:
To date, no study has used ds-TMS to investigate short intra-hemispheric interactions between the somatosensory areas and primary motor cortex (M1).METHODS:
We examined somatosensory-M1 interactions in the left hemisphere in six experiments using ds-TMS. In Experiment 1 (nâ¯=â¯16), the effects of different conditioning stimulus (CS) intensities on somatosensory-M1 interactions were measured with 1 and 2.5â¯ms inter-stimulus intervals (ISIs). In Experiment 2 (nâ¯=â¯16), the time-course of somatosensoy-M1 interactions was studied using supra-threshold CS intensity at 6 different ISIs. In Experiment 3 (nâ¯=â¯16), the time-course of short-interval cortical inhibition (SICI) and effects of different CS intensities on SICI were measured similar to Experiments 1 and 2. Experiment 4 (nâ¯=â¯13) examined the effects of active contraction on SICI and somatosensory-M1 inhibition. Experiments 5 and 6 (nâ¯=â¯10) examined the interactions between SAI with either 1â¯ms SICI or somatosensory-M1 inhibition.RESULTS:
Experiments 1 and 2 revealed reduced MEP amplitudes when applying somatosensory CS 1â¯ms prior to M1 TS with 140 and 160% CS intensities. Experiment 3 demonstrated that SICI at 1 and 2.5â¯ms did not correlate with somatosensory-M1 inhibition. Experiment 4 found that SICI but not somatosensory-M1 inhibition was abolished with active contraction. The results of Experiments 5-6 showed SAI was disinhibited in presence of somatosensory-M1 while SAI was increased in presence of SICI.CONCLUSION:
Collectively, the results support the notion that the somatosensory areas inhibit the ipsilateral M1 at very short latencies.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Corteza Somatosensorial
/
Potenciales Evocados Motores
/
Estimulación Magnética Transcraneal
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Corteza Motora
/
Inhibición Neural
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Brain Stimul
Asunto de la revista:
CEREBRO
Año:
2019
Tipo del documento:
Article