京都大学 大学院医学研究科 人間健康科学系専攻 病理学研究室（形態形成医療科学）

熊谷さんの卒業研究がAnat Recに受諾されました。１次脳溝（脳のしわ）が、どのように最初できてくるかを検討しました。

• 妊娠11週から16週までの33のサンプルから得られた高解像度の磁気共鳴画像(頭殿長<130 mm)を使用して、脳溝形成の出現時期と形態学的および形態計測学的特徴を特定。
• 検出時期は、脳梁では12週未満、海馬、鳥骨、頭頂後頭溝では13週未満、円形島状溝では15週未満、嗅溝はときおり検出され、帯状溝は特定されていない。円形の島状溝が徐々に現れ形を変える
• 測定された溝はどれも頭殿長と相関しない。溝はある程度の距離にわたって同時に発生する可能性あり。 出生前診断や神経発達障害の研究に大きな影響を与える可能性

70. Kumagai M, Kanahashi M,  Imai H, Otani H, Takakuwa T.
Primary sulci formation in human cerebral cortex development. Anat Rec (Hoboken) 2025, in press 

Abstract

We aimed to determine the timing of appearance and the morphologic and morphometric features of the initial human cerebral sulcal formation. Using high-resolution magnetic resonance images obtained from 33 samples between 11 and 16 weeks (w) of gestation (crown-rump length <130 mm), the cerebral surface and internal structures on serial two-dimensional planes and all possible sulci on three-dimensional reconstructions were marked, allowing comparison of the positions of the sulci in the samples and inter-samples. Our method provided accurate conclusions regarding the timing of sulcal formation. Detection timing was as early as and earlier than those in previous studies using anatomical dissection and magnetic resonance imaging (MRI), respectively: <12 w for the callosum, <13 w for the hippocampal, calcarine, and parieto-occipital sulci, and <15 w for the lateral sulcus. Occasionally, an olfactory sulcus was detected. However, the cingulate sulcus could not be definitely identified. The lateral sulcus gradually appeared and changed shape. The lengths of the left and right sides of the olfactory sulci and the left side of the hippocampal sulcus increased linearly with the CRL. The length of the right side of the hippocampal sulcus and the left and right sides of the calcarine, parieto-occipital, and not determined_a sulci did not increase with the CRL The depth of the all sulci, except for the parieto-occipital sulci, increased linearly with the CRL. The sulci might not arise as if they elongate gradually but arise simultaneously over some distance. We determined the timing of the initial sulcal formation using high-resolution MRI. Our findings may significantly impact prenatal diagnosis and research on neurodevelopmental disorders.