Leonard C M, Puranik C, Kuldau J M, Lombardino L J
Department of Neuroscience, University of Florida, Gainesville 32610, USA.
Cereb Cortex. 1998 Jul-Aug;8(5):397-406. doi: 10.1093/cercor/8.5.397.
Interpersonal communication via the auditory modality is fundamental to normal human development. One of the prominent anatomical specializations supporting this communication is the transverse gyrus of Heschl on the superior surface of the temporal lobe. This gyrus frequently appears duplicated, either by a sulcus indenting the crown of an initially single gyrus (common stem), or by a complete posterior duplication. The frequency of these duplications has been reported to be elevated in populations with learning disabilities and genetic anomalies. The significance of this observation is unclear, however, due to conflicting reports of the base rate of duplication and the location of relevant sulcal landmarks. In this study we report the variation in frequency and location of the sulcal boundaries of Heschl's gyrus in volumetric magnetic resonance imaging scans of 105 normal controls aged 5-65. The major results were as follows: (i) duplications were unstable--the frequency of duplication ranged from 20 to 60% depending on distance from the midline; (ii) common stem duplications were more frequent than posterior duplications, particularly in the right hemisphere. Intra- and interindividual instability in sulcal landmarks pose serious obstacles to the attempt to map behavioral function onto the brain. Novel methods for dealing with structural variation are needed to facilitate the development of valid mapping techniques.
通过听觉通道进行的人际交流对于人类的正常发育至关重要。支持这种交流的一个突出的解剖学特化结构是颞叶上表面的赫氏横回。这个脑回经常出现重复，要么是由一条沟切入最初单一脑回的顶部（共同干），要么是完全向后重复。据报道，在有学习障碍和遗传异常的人群中，这些重复的频率有所升高。然而，由于关于重复的基础发生率和相关沟回标志位置的报道相互矛盾，这一观察结果的意义尚不清楚。在本研究中，我们报告了105名年龄在5至65岁的正常对照者的容积磁共振成像扫描中赫氏脑回沟边界频率和位置的变化。主要结果如下：（i）重复是不稳定的——重复频率根据距中线的距离在20%至60%之间变化；（ii）共同干重复比后重复更常见，尤其是在右半球。沟回标志的个体内和个体间不稳定性对将行为功能映射到大脑的尝试构成了严重障碍。需要新的方法来处理结构变异，以促进有效映射技术的发展。
