Data_Sheet_3_A Systematic Approach to Dissection of the Equine Brain–Evaluation of a Species-Adapted Protocol for Beginners and Experts.PDF

Introduction of new imaging modalities for the equine brain have refocused attention on the horse as a natural model for ethological, neuroanatomical, and neuroscientific investigations. As opposed to imaging studies, strategies for equine neurodissection still lack a structured approach, standardization and reproducibility. In contrast to other species, where adapted protocols for sampling have been published, no comparable guideline is currently available for equids. Hence, we developed a species-specific slice protocol for whole brain vs. hemispheric dissection and tested its applicability and practicability in the field, as well as its neuroanatomical accuracy and reproducibility. Dissection steps are concisely described and depicted by schematic illustrations, photographs and instructional videos. Care was taken to show the brain in relation to the raters' hands, cutting devices and bench surface. Guidance is based on a minimum of external anatomical landmarks followed by geometric instructions that led to procurement of 14 targeted slabs. The protocol was performed on 55 formalin-fixed brains by three groups of investigators with different neuroanatomical skills. Validation of brain dissection outcomes addressed the aptitude of slabs for neuroanatomical studies as opposed to simplified routine diagnostic purposes. Across all raters, as much as 95.2% of slabs were appropriate for neuroanatomical studies, and 100% of slabs qualified for a routine diagnostic setting. Neither autolysis nor subfixation significantly affected neuroanatomical accuracy score, while a significant negative effect was observed with brain extraction artifacts. Procedure times ranged from 14 to 66 min and reached a mean duration of 23.25 ± 7.93 min in the last of five trials in inexperienced raters vs. 16 ± 2.83 min in experts, while acceleration of the dissection did not negatively impact neuroanatomical accuracy. This protocol, derived analogously to the consensus report of the International Veterinary Epilepsy Task Force in dogs and cats, allows for systematic, quick and easy dissection of the equine brain, even for inexperienced investigators. Obtained slabs feature virtually all functional subcompartments at suitable planes for both diagnostic and neuroscientific investigations and complement the data obtained from imaging studies. The instructive protocol and brain dissection videos are available in Supplementary Material.

新成像模态在马脑研究中的应用，重新聚焦了对马作为行为学、神经解剖学和神经科学研究的自然模型的关注。与成像研究不同，马神经解剖学分割的策略仍缺乏结构化的方法、标准化和可重复性。与其他物种不同，尽管已发布了适用于样本采集的适应方案，但目前对于马科动物尚无相应的指南。因此，我们开发了针对全脑与半球解剖的物种特异性切片方案，并对其在现场的应用性、实用性、神经解剖学准确性和可重复性进行了测试。解剖步骤通过示意图、照片和教学视频进行了简洁描述和展示。在展示过程中，我们特别注意将大脑与评估者的手、切割工具和实验台表面之间的关系进行说明。指导基于最少的外部解剖学标志，随后是几何指令，这些指令引导获取了14个目标切片。该方案由三组不同神经解剖学技能的研究人员在对55个福尔马林固定的脑样本进行操作时实施。对大脑解剖结果的验证涉及评估切片在神经解剖学研究中的应用能力，而非简化常规诊断目的。在所有评估者中，高达95.2%的切片适用于神经解剖学研究，100%的切片符合常规诊断设置的要求。自溶和亚固定对神经解剖学准确评分没有显著影响，而脑提取伪影观察到显著的负面影响。程序时间从14分钟到66分钟不等，在经验不足的评估者进行的最后五次试验中平均持续时间为23.25 ± 7.93分钟，而在专家手中平均持续时间为16 ± 2.83分钟，而解剖速度的加快并未对神经解剖学准确性产生负面影响。此方案类似于国际兽医癫痫工作组（International Veterinary Epilepsy Task Force）对狗和猫的共识报告，允许系统化、快速且易于进行马脑的解剖，即使对于缺乏经验的调查人员也是如此。获得的切片几乎包含了所有功能亚区，在适合诊断和神经科学研究的位置，并补充了来自成像研究的数据。指导方案和大脑解剖视频可在补充材料中找到。