Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università, 16, 35020, Legnaro, PD, Italy.
Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra, 43, 40064, Ozzano dell'Emilia, BO, Italy.
Brain Struct Funct. 2022 Jun;227(5):1871-1891. doi: 10.1007/s00429-022-02479-w. Epub 2022 Mar 26.
Areas dedicated to higher brain functions such as the orbitofrontal cortex (OFC) are thought to be unique to hominidae. The OFC is involved in social behavior, reward and punishment encoding and emotional control. Here, we focused on the putative corresponding area in the sheep to assess its homology to the OFC in humans. We used classical histology in five sheep (Ovis aries) and four chimpanzees (Pan troglodytes) as a six-layered-cortex primate, and Diffusion Tensor Imaging (DTI) in three sheep and five human brains. Nissl's staining exhibited a certain alteration in cortical lamination since no layer IV was found in the sheep. A reduction of the total cortical thickness was also evident together with a reduction of the prevalence of layer one and an increased layer two on the total thickness. Tractography of the sheep OFC, on the other hand, revealed similarities both with human tracts and those described in the literature, as well as a higher number of cortico-cortical fibers connecting the OFC with the visual areas in the right hemisphere. Our results evidenced the presence of the basic components necessary for complex abstract thought in the sheep and a pronounced laterality, often associated with greater efficiency of a certain function, suggested an evolutionary adaptation of this prey species.
被认为专门用于更高脑功能的区域，如眶额皮质（OFC），被认为是人类所独有的。OFC 参与社交行为、奖励和惩罚编码以及情绪控制。在这里，我们专注于羊中假定的对应区域，以评估其与人类 OFC 的同源性。我们使用了经典组织学在五只羊（Ovis aries）和四只黑猩猩（Pan troglodytes）作为六层皮质灵长类动物，以及在三只羊和五个人脑中的弥散张量成像（DTI）。尼氏染色显示出皮质层状结构的某些改变，因为在羊中没有发现第四层。总皮质厚度的减少也很明显，同时，一层的普遍性减少，而总厚度上的二层增加。另一方面，羊 OFC 的轨迹显示出与人类轨迹以及文献中描述的轨迹的相似性，以及与右侧视觉区域连接的 OFC 的皮质-皮质纤维数量增加。我们的结果表明，羊中存在进行复杂抽象思维的基本组成部分，并且表现出明显的偏侧性，这通常与特定功能的更高效率相关，这表明这种猎物物种发生了进化适应。
