In this study, we aimed to provide a neuroanatomy atlas derived from cross-sectional and magnetic resonance imaging (MRI) of the encephalon of the brown bear (Ursus arctos). A postmortem brain analysis using magnetic resonance imaging (MRI - 1,5T; a high-resolution submillimeter three-dimensional T1-3D FFE) and cross-sectional macroscopic anatomy methods revealed major embryological and anatomical subdivisions of the encephalon, including the ventricular system. Most of the internal structures were comparably identifiable in both methods. The tractus olfactorius medialis, corpus subthalamicum, brachium colliculi rostralis, fasciculus longitudinalis medialis, nuclei vestibulares, velum medullare rostrale, nucleus fastigii, fasciculi cuneatus et gracilis were identified entirely by cross-sectional macroscopic analysis. However, the glandula pinealis, lemniscus lateralis and nuclei rhaphe were visualized only with MRI. Gross neuroanatomic analysis provided information about sulci and gyri of the cerebral hemispheres, components of the vermis and cerebellar hemispheres, and relative size and morphology of constituents of the rhinencephalon and cerebellum constituents. Similarities and discrepancies in identification of structures provided by both methods, as well as hallmarks of the structures facilitating identification using these methods are discussed. Finally, we compare the brown bear encephalon with other carnivores and discuss most of the identified structures compared to those of the domestic dog, the domestic cat, Ursidae and Mustelidae families and Pinnipedia clade.

中文翻译：

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棕熊（食肉目，Ursus arctos L.，1758）与其他食肉动物的大脑解剖结构比较：使用 MRI 的横断面研究。

在这项研究中，我们的目的是提供从棕熊（Ursus arctos）脑部的横截面和磁共振成像（MRI）中获得的神经解剖学图谱。使用磁共振成像（MRI - 1,5T；高分辨率亚毫米三维 T1-3D FFE）和横截面宏观解剖方法进行的死后大脑分析揭示了脑的主要胚胎学和解剖学细分，包括脑室系统。大多数内部结构在两种方法中都可以比较地识别。内侧嗅束、丘脑下体、丘臂臂、内侧纵束、前庭核、延髓喙、快核、楔形束和股薄肌完全通过横截面宏观分析来识别。然而，松果体、外侧丘系和缝核只能通过 MRI 观察到。大体神经解剖学分析提供了有关大脑半球的沟和回、蚓部和小脑半球的组成部分以及鼻脑和小脑组成部分的相对大小和形态的信息。讨论了两种方法所提供的结构识别的相似性和差异，以及有助于使用这些方法进行识别的结构的标志。最后，我们将棕熊的脑部与其他食肉动物进行比较，并与家犬、家猫、熊科和鼬科以及鳍足亚支的脑部进行比较，讨论大多数已识别的结构。