Human somatosensory cortical activation strengths:: comparison between males and females and age-related changes
Human somatosensory cortical activation strengths:: comparison between males and females and age-related changes
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DOI：
10.1016/s0006-8993(98)01215-3
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发表时间：
1999-02-13
期刊：
影响因子：
2.9
通讯作者：
Ilmoniemi, RJ
中科院分区：
文献类型：
--
作者：
Huttunen, J;Wikström, H;Ilmoniemi, RJ
许多头皮记录的诱发电位(EP)偏转的幅度女性高于男性，老年人高于年轻受试者。由于EP在很大程度上依赖于头盖骨的电导率，目前尚不清楚这些差异是否反映了神经元激活强度的年龄和性别变化，或者体积导体的变化。诱发磁场不受脑组织电导的显著影响，因此比诱发电位更直接地反映神经元的激活。本文报道了43例(男21例)20~73岁(男51+/-18岁，女51+/-14岁)健康受试者初级躯体感觉皮层(SI)体感诱发野(SEF)的年龄和性别效应。用刺激右侧正中神经后左侧SI的N20m、P35m和P60m偏转峰处的等效电流偶极子(ECDs)来估计神经元的激活强度。女性N20m和P35m(但不包括P60m)的峰潜伏期短于男性。男性N20M潜伏期与年龄呈正相关，与年龄无关。对于任何偏转，男性和女性的ECD幅度没有差异。N20m ECD强度与年龄呈显著正相关(r=0.39，p<；0.01)，而P35m和P60m ECD强度与年龄无显著相关。因此，结果没有揭示躯体感觉皮层激活强度的性别差异，这意味着诱发电位的这种差异可能是由于体积导体的性别差异所致。另一方面，研究结果表明，大脑皮质兴奋性略有随年龄增长而增加。(C)1999 Elsevier Science B.V.保留所有权利。
The amplitudes of many scalp-recorded evoked potential (EP) deflections are higher in females than in males, and in elderly than in young subjects. Since EPs critically depend on the electric conductivity of the cranium, it is not known whether these differences reflect age- and gender-dependent changes in the intensity of neuronal activation, or changes in the volume conductor. Evoked magnetic fields are not significantly affected by the conductivities of the cranial tissues and therefore reflect more directly the neuronal activation than EPs. We report here on the effects of age and gender on somatosensory evoked fields (SEFs) from the primary somatosensory cortex (SI) in 43 healthy subjects (21 males) aged from 20 to 73 years (males 51 +/- 18 years, females 51 +/- 14 years). The intensity of neuronal activation was estimated with equivalent current dipoles (ECDs) found at the peaks of the N20m, P35m and P60m deflections from the left SI after right median nerve stimulation. The peak latencies of N20m and P35m (but not of P60m) were shorter in females than in males. The N20m latency was positively correlated with age in males, but otherwise the latencies did not correlate with age. The ECD amplitudes did not differ between males and females for any of the deflections. The N20m ECD strength showed a significant positive correlation (r = 0.39, p < 0.01) with age while P35m and P60m ECD strengths did not. The results thus did not disclose gender differences in the activation strengths of the somatosensory cortex, implying that such differences in evoked potentials may possibly be due to gender differences in the volume conductor. On the other hand, the results suggest a slight age-related increase in cortical excitability. (C) 1999 Elsevier Science B.V. All rights reserved.