WEKO3
アイテム
Somatosensory Evoked Magnetic Fields In Humans
https://ir.soken.ac.jp/records/1097
https://ir.soken.ac.jp/records/1097a3125abc-783f-4547-8b2a-57e9230d9812
名前 / ファイル | ライセンス | アクション |
---|---|---|
要旨・審査要旨 / Abstract, Screening Result (353.2 kB)
|
||
本文 (10.4 MB)
|
Item type | 学位論文 / Thesis or Dissertation(1) | |||||
---|---|---|---|---|---|---|
公開日 | 2010-02-22 | |||||
タイトル | ||||||
タイトル | Somatosensory Evoked Magnetic Fields In Humans | |||||
タイトル | ||||||
タイトル | Somatosensory Evoked Magnetic Fields In Humans | |||||
言語 | en | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_46ec | |||||
資源タイプ | thesis | |||||
著者名 |
下条, 素子
× 下条, 素子 |
|||||
フリガナ |
シモジョウ, モトコ
× シモジョウ, モトコ |
|||||
著者 |
SHIMOJO, Motoko
× SHIMOJO, Motoko |
|||||
学位授与機関 | ||||||
学位授与機関名 | 総合研究大学院大学 | |||||
学位名 | ||||||
学位名 | 博士(医学) | |||||
学位記番号 | ||||||
内容記述タイプ | Other | |||||
内容記述 | 総研大甲第412号 | |||||
研究科 | ||||||
値 | 生命科学研究科 | |||||
専攻 | ||||||
値 | 20 生理科学専攻 | |||||
学位授与年月日 | ||||||
学位授与年月日 | 1999-03-24 | |||||
学位授与年度 | ||||||
値 | 1998 | |||||
要旨 | ||||||
内容記述タイプ | Other | |||||
内容記述 | She mainly studied MEG results on somatosensory functions in humans, termed "somatosensory evoked magnetic fields (SEF)". By examining SEF, detailed functional anatomy of the primary and secondary somatosensory cortex (SI and SII) in humans have been elucidated. <br /> She reported three studies on SEF in this thesis. In the first study, she analyzed receptive fields in SI for lower limb stimulation in detail. This is the first systematic study on this matter. In the second and third studies, she analyzed the intracerebral interactions caused by simultaneous stimulation of the same nerve of the upper limb (median nerve) and lower limb (posterior tibial nerve). By these studies, they found that not only SI but also SII is the most important area for sensory processing of stimulation applied to the bilateral sides of the body. <br /><br />1. Differentiation of receptive fields in the sensory cortex following stimulation of varuous nerves of the lower limb in humans: a magnetoencephalographic study. <br /><br /> They investigated magnetoencephalography (MEG) following siimulation of the posterior tibial (PT) and sural nerve (SU) at the ankle, the peroneal nerve (PE) at the knee and the femoral nerve (FE) overlying the inguinal ligament in 7 normal subjects (14 limbs), and confirmed its usefulness to clarify the detailed differentiation of the receptive fields in the lower limb area of the primary sensory cortex (SI) in humans. The results were summarized as follows; (1) The location of the equivalent current dipole (ECD) estimated by the magnetic fields following stimulation of the PT and SU were very close to each other, along the interhemispheric fissure in all 14 limbs. They were directed horizontally to the hemisphere ipsilateral to the stimulated nerve. (2) ECD following stimulation of FE was clearly different from others, in terms of the location and/or direction,in all 14 limbs. The ECD of 14 limbs were classified into two types according to the distance of ECD location between PT and FE; type 1 (longer than 1 cm, 9 limbs) and type 2 (shorter than 1 cm, 5 limbs). The ECD following FE stimulation was located on the crown of the postcentral gyrus, or at the edge of the interhemispheric fissure in type 1, and was close to those following PT and SU stimulation along the interhemispheric fissure in type 2. (3) ECD following PE stimulation was along the interhemispheric fissure in all 14 limbs like PT and SU. Its location was slightly but significantly higher than that of PT and SU in type 1, and was close to those following PT and SU in type 2. The present findings indicated that approximately 65 % (9/14) of the limbs show the particular receptive fields compatible with the homunculus. Large inter- and the intraindividual (left-right) difference found in the present study indicated a large anatomical variation in the area of the lower limb in SI in humans. <br /><br />2. Magnetoencephalographic study of intracerebral interaction caused by bilateral posterior tibial nerve stimulation in man. <br /><br /> They studied somatosensory evoked magnetic fields (SEFs) following stimulation of bilateral posterior tibial nerves ("bilateral" waveform) in normal subjects to determine the inter- and intra-hemispheric interference effects caused by activation of sensory areas in bilateral hemispheres. Activated areas in the primary and second sensory cortices (SI and SII) in each hemisphere following bilateral stimulation were clearly identified by estimation of the double best-fitted equivalent current dipoles (ECD) using the spherical head model, and the large inter-individual differences were identified. SEFs following the right posterior tibial nerve stimulation and those following the left stimulation were summated ("summated" waveform). The "difference" waveform was induced by a subtraction of "bilateral" waveforms from the "summated" waveform. Short-latency deflections showed no consistent changes between the "summated" and "bilateral" waveforms, but the long-latency deflection, the N100m-P100m, in the "bilateral" waveform was significantly (P<0.02) reduced in amplitude as compared with the "summated" waveform. The differences were clearly identified in the "difference" waveform, in which the main deflections, U100m-D100m, were found. The ECDs of the short-latency deflections were located in SI contralateral to the stimulated nerve, but the ECDs of the N100m-P100m were located in bilateral SII which are considered to receive ascending signals from the body bilaterally. Therefore, some inhibitory interactions might take place in SII by receiving inputs from the body bilaterally. <br /><br />3. Intracerebral interactions caused by bilateral median nerve stimulation in man. A magnetoencephalographic study. <br /><br /> Somatosensory evoked magnetic fields (SEFs) following stimulation of the median nerves bilaterally ("bilateral" waveform) were examined in normal subjects to determine the interference effects of activations of sensory areas in bilateral hemispheres. SEFs following right median nerve stimulation and those following left median nerve stimulation were summated ("summated" waveform). A "difference" waveform was induced by subtraction of the "bilateral" waveform from "summated" waveform. Short-latency deflections showed no consistent differences between the "summated" and "bilateral" waveforms, but the middle-latency deflection, N60m-P60m, in the "bilateral" waveform was significantly (P<0.01) smaller than that in the "summated" waveform. The long-latency deflection, the N90m-P90m, in the "bilateral" waveform was markedly (P<0.001) reduced in amplitude as compared with "summated" waveform. The differences were clearly identified in the "difference" waveform, in which the main deflections, U90m-D90m, were found in all subjects. Equivalent current dipoles (ECDs) of the short- and middle- latency deflections were located in the primary sensory cortex (SI) contralateral to the stimulated nerve, but ECDs of the N90m-P90m and U90m-D90m were located in bilateral second sensory cortices (SII) which are considered to receive ascending signals from bilateral sides of the body. | |||||
所蔵 | ||||||
値 | 有 | |||||
フォーマット | ||||||
内容記述タイプ | Other | |||||
内容記述 | application/pdf |