Data_Sheet_4_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.

新型马脑成像模态的引入，重新聚焦了人们对马作为生态学、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，马脑神经解构的策略仍缺乏结构化的方法、标准化和可重复性。与其他物种相比，尽管已发表针对样本采集的适应方案，但对于马科动物，目前尚无相应的指南。因此，我们开发了一种针对全脑与半球解构的物种特异性切片方案，并在现场测试了其适用性和实用性，以及其神经解剖学的准确性和可重复性。解构步骤以简明扼要的方式通过示意图、照片和教学视频进行描述和展示。特别注重展示大脑与评定者之手、切割工具和实验台表面的关系。指导基于外部解剖学标志点的最少使用，随后是几何指令，这些指令有助于获取14个目标切片。该方案由三组不同神经解剖学技能的研究者对55个甲醛固定的脑组织进行了实施。对脑解构结果的验证考虑了切片在神经解剖学研究中的适用性，而非简化常规诊断目的。在所有评定者中，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度评分无显著影响，而大脑提取伪影观察到了显著的负面效应。手术时间从14分钟到66分钟不等，在经验不足的评定者中，最后一次试验的平均持续时间为23.25 ± 7.93分钟，而在专家中为16 ± 2.83分钟，而加速解构并未对神经解剖学准确度产生负面影响。本方案借鉴国际兽医癫痫任务小组在犬和猫的共识报告，允许对马脑进行系统、快速且简便的解构，即便对于经验不足的研究者也是如此。获得的切片几乎包含了所有功能亚区，在适宜的平面上既可用于诊断研究，也可用于神经科学研究，并补充了成像研究获得的数据。指导性方案和脑解构视频可在补充材料中找到。