Division of Diagnostic and Interventional Neuroradiology, Department of Radiology, University of Basel Hospital, Petersgraben 4, 4031, Basel, Switzerland.
Department of Neuroradiology, University of Heidelberg Medical School, INF 400, 69120, Heidelberg, Germany.
Brain Struct Funct. 2017 Nov;222(8):3587-3603. doi: 10.1007/s00429-017-1419-x. Epub 2017 Apr 10.
Morphological variations of the first transverse Heschl's gyrus (HG) in the human auditory cortex (AC) are common, yet little is known about their functional implication. We investigated individual morphology and function of HG variations in the AC of 41 musicians, using structural and functional magnetic resonance imaging (fMRI) as well as magnetoencephalography (MEG). Four main morphotypes of HG were (i) single HG, (ii) common stem duplication (CSD), (iii) complete posterior duplication (CPD), and (iv) multiple duplications (MD). The vast majority of musicians (90%) exhibited HG multiplications (type ii-iv) in either one (39%) or both (51%) hemispheres. In 27% of musicians, MD with up to four gyri were found. To probe the functional contribution of HG multiplications to auditory processing we performed fMRI and MEG with auditory stimulation using analogous instrumental tone paradigms. Both methods pointed to the recruitment of all parts of HG during auditory stimulation, including multiplications if present. FMRI activations extended with the degree of HG gyrification. MEG source waveform patterns were distinct for the different types of HG: (i) hemispheres with single HG and (ii) CSD exhibited dominant N1 responses, whereas hemispheres with (iii) CPD and (iv) MD exhibited dominant P1 responses. N1 dipole amplitudes correlated with the localization of the first complete Heschl's sulcus (cHS), designating the most posterior anatomical border of HG. P2 amplitudes were significantly higher in professional as compared to amateur musicians. The results suggest that HG multiplications occur much more frequently in musicians than in the general population and constitute a functional unit with HG.
人类听觉皮层（AC）第一横回（HG）的形态变异很常见，但它们的功能意义知之甚少。我们使用结构和功能磁共振成像（fMRI）以及脑磁图（MEG）研究了 41 位音乐家的 AC 中 HG 变异的个体形态和功能。HG 有四种主要的形态类型：（i）单个 HG，（ii）常见干重复（CSD），（iii）完全后重复（CPD）和（iv）多重重复（MD）。绝大多数音乐家（90%）在一个（39%）或两个（51%）半球中表现出 HG 重复（类型 ii-iv）。在 27%的音乐家中，发现 MD 多达四个回。为了探究 HG 重复对听觉处理的功能贡献，我们使用类似的乐器音范式进行了 fMRI 和 MEG 听觉刺激。这两种方法都表明，在听觉刺激期间，HG 的所有部分都被募集，包括如果存在重复。FMRI 激活随着 HG 回波的程度而扩展。MEG 源波形模式因 HG 的不同类型而异：（i）具有单个 HG 的半球和（ii）CSD 表现出主导的 N1 反应，而具有（iii）CPD 和（iv）MD 的半球表现出主导的 P1 反应。N1 偶极子幅度与第一完整 Heschl 沟（cHS）的定位相关，该定位表示 HG 的最后解剖边界。与业余音乐家相比，专业音乐家的 P2 幅度明显更高。结果表明，HG 重复在音乐家中比在普通人群中更常见，并且构成了与 HG 相关的功能单元。
