Department of Neurosurgery, Rush University Medical Center, 1725 W. Harrison Street, Suite 855, Chicago, IL, 60612, USA.
Department of Psychiatry and Behavioral Sciences, Rush University Medical Center, 1645 W. Jackson Boulevard, Suite 400, Chicago, IL, 60612, USA.
Brain Struct Funct. 2020 Apr;225(3):985-993. doi: 10.1007/s00429-020-02050-5. Epub 2020 Mar 2.
Massa intermedia (MI) is an inconsistent midline structure in the human brain that is absent in approximately 30% of the population. Absence of MI is seen more frequently in schizophrenia spectrum disorder and bipolar disorder. However, very little is known about the normal role of MI in the human brain. The purpose of this study was to investigate the role of human MI in cortical and subcortical cognitive processing as determined by differences between subjects with and without MI. Using the Human Connectome Project database, a cohort of randomly selected participants were selected to (1) identify presence, absence, and size of MI, and (2) explore possible cognitive process mediated by the presence of MI. Four hundred and two brains were included (216 females) in the final analysis. Four independent blind raters identified 360 brains with MI (202 females) and 42 without MI using anatomical T1-weighted MR scans. Presence of MI was significantly more prevalent in female participant (p = 0.005) and they had significantly larger size of MI (p = 0.001 and 0.000 for anteroposterior and craniocaudal dimensions, respectively). There were no statistically significant differences in the presence of MI with regards to age, race and ethnicity. Further analysis revealed gender, flanker test, and loneliness as predictor of the presence of MI in a Firth logistic regression model (p = 0.0004). This is the largest study of human MI to date. MI may contribute to interhemispheric cortical and subcortical connectivity with resulting subtle neuropsychological differences among individuals with a present versus absent MI.
间脑（MI）是人类大脑中一条不一致的中线结构，大约 30%的人群中不存在 MI。MI 缺失在精神分裂症谱系障碍和双相情感障碍中更为常见。然而，关于 MI 在人类大脑中的正常作用知之甚少。本研究旨在通过比较存在和不存在 MI 的受试者之间的差异，研究人类 MI 在皮质和皮质下认知处理中的作用。
使用人类连接组计划数据库，随机选择了一组参与者，（1）确定 MI 的存在、缺失和大小，以及（2）探索 MI 存在介导的可能认知过程。最终分析包括 402 个大脑（216 名女性）。4 名独立的盲评员使用解剖 T1 加权磁共振扫描识别出 360 个具有 MI（202 名女性）和 42 个没有 MI 的大脑。
MI 的存在在女性参与者中更为常见（p=0.005），并且 MI 的大小明显更大（p=0.001 和 0.000，分别用于前后和头尾维度）。MI 的存在与年龄、种族和民族无关，没有统计学差异。进一步的分析表明，性别、侧抑制测试和孤独感是 Firth 逻辑回归模型中 MI 存在的预测因素（p=0.0004）。
这是迄今为止关于人类 MI 的最大研究。MI 可能有助于大脑半球间皮质和皮质下的连接，从而导致存在和不存在 MI 的个体之间存在微妙的神经心理学差异。
