胎儿海马结构的半球间不对称性与性别二态性

The present research has confirmed that there are hemispheric asymmetry and sexual dimorphism in the adult hippocampal formation, so as in the children or neonate. However, little is known about the hemispheric asymmetry and sexual dimorphism in the fetal hippocampal formation. 310 human fetal specimens, including 155 males and 155 females, of 10-40 weeks gestational age with appropriately developmental brains are selected and the brains are scanned by 7.0T MRI. The morphology, hemispheric asymmetry and sexual dimorphism of the human fetal hippocampal formation (includig the dentate gyrus, cornu ammonis, subiculum and parahippocampal gyrus)are analyzed on the postmortem MRI. As follows: 1. The curved morphological changes and the laminar organization of the hippocampal formation at different gestational age are analyzed; 2. The hippocampal formation is divided into the dentate gyrus (including CA4), cornu ammonis(CA1-3) and subiculum using the Amira software according to the histological sections of the same gestational age, then the three dimensional visualization models are obtained. The diameters and volume of each segmented area are obtained. The degree, the exact area, the original gestational age, and the developmental changes of the hemispheric asymmetry and sexual dimorphism of the human fetal hippocampal formation are obtained. This study can supply morphological and diagnostic basis for the assessment of fetal hippocampal formation in the uterus in clinical settings, increase the number of healthy newborns and improveme the survival rate of prematures.

现有研究证实成人海马结构存在半球间不对称性与性别二态性，并可追溯至儿童或新生儿，但上述现象在胎儿中的存在状况尚知之甚少。 本研究选取310例10-40周脑发育正常的人类胎儿标本，男、女各半，进行7.0T MRI扫描，于标本MRI上分析海马结构（含齿状回、海马角、下托与海马旁回）的形态发育规律及其半球间不对称性与性别二态性。 包括：1. 不同孕龄时期海马结构卷曲发育及其内层状结构的形态变化；2. 利用Amira软件，参照同胎龄组织学切片，将海马结构分割为齿状回（含CA4区）、海马角（含CA1-3区）与下托，进行三维重建，测量上述分割结构的径线及体积，分析其不对称性与性别二态性的大小、起始胎龄、存在部位及发育变化。 本研究可为临床宫内胎儿海马结构发育异常相关疾病提供形态学基础或诊断参考，以提高人口素质，利于优生。

现有研究证实成人海马结构存在半球间不对称性与性别二态性，并可追溯至儿童或新生儿，但上述现象在胎儿中的存在状况尚知之甚少。 本研究搜集了300余例10-40周脑发育正常的人类胎儿标本，全部进行了3.0TMRI扫描，妊娠中期部分(约100例)进行7.0T MRI扫描，于标本MRI上分析海马结构（含齿状回、海马角、下托与海马旁回）的形态发育规律及其半球间不对称性与性别二态性。 包括：1. 不同孕龄时期海马结构卷曲发育及其内层状结构的形态变化；2. 利用Amira软件，参照同胎龄组织学切片，将海马结构分割为齿状回（含CA4区）、海马角（含CA1-3区）与下托，进行三维重建，测量上述分割结构的径线及体积，分析其不对称性与性别二态性的大小、起始胎龄、存在部位及发育变化；3.分析了胎儿肾上腺与眼球的形态发育变化。本研究可为临床宫内胎儿形态发育异常相关疾病提供形态学基础或诊断参考，以提高人口素质，利于优生。