杏仁核,前脑中的一组复杂的细胞核,控制脊椎动物的情绪和情绪相关行为。当前的研究旨在了解斑马鱼等射线鳍鱼的杏仁核进化,因为该地区与社会行为和人类精神疾病的相关性。杏仁核的清晰分子定义及其与哺乳动物之一的进化发育关系对于情感障碍和自闭症的斑马鱼模型至关重要。在这次审查中,我认为,人工模型和对嗅觉系统组织的关注为发现斑马鱼和哺乳动物的情感系统之间的深层祖先关系提供了理想的工具。评论的重点是“扩展杏仁核”,“是指杏仁核下的杏仁核区域,包括生殖和社会行为所需的中央(自主神经)和内侧(嗅觉)杏仁核。两栖动物,sauropsids,肺鱼与哺乳动物的基本杏仁核地面计划具有许多特征,正如分子和病理学研究表明的那样。进一步探索基础鱼类脊椎动物杏仁核的进化需要研究人员测试这些“基于四足动物的”概念。历史上,这是一项艰巨的任务,因为基础衍生的鱼类脊椎动物的前脑看起来与更熟悉的四足动物的前脑非常不同。一种极端的情况是像斑马鱼一样的射线鳍鱼(Actinopterygii),因为它们的端脑通过一种独特的向外生长过程发展,称为外翻。直到今天,科学家们一直在努力确定外翻的端脑与非放线足脊椎动物的比较。使用硬骨鱼斑马鱼作为遗传模型,比较神经学家开始建立可量化的分子定义,以便在射线鳍鱼和四足动物之间进行直接比较。在这次审查中,我讨论了斑马鱼杏仁核地面计划的最新发现如何为确定杏仁核进化和功能的发育限制提供了机会。此外,我解释了斑马鱼丘脑前隆起(PThE)在拓扑上与内侧杏仁核和外侧嗅道(nLOT)的核之间的关系。事实上,我认为这些先前误解的嗅觉结构是放线体和四足杏仁核之间最关键的进化联系。在这种情况下,我还将解释为什么识别PThE和nLOT对于理解端脑外翻至关重要。认识到这些解剖学标志可以直接比较斑马鱼和哺乳动物的杏仁核。最终,斑马鱼杏仁核的新概念将克服当前的教条,并对行动的杏仁核认知和情感回路达成全面的理解。
The amygdala, a complex array of nuclei in the forebrain, controls emotions and emotion-related behaviors in vertebrates. Current research aims to understand the amygdala\'s evolution in ray-finned fish such as zebrafish because of the region\'s relevance for social behavior and human psychiatric disorders. Clear-cut molecular definitions of the amygdala and its evolutionary-developmental relationship to the one of mammals are critical for zebrafish models of affective disorders and autism. In this review, I argue that the prosomeric model and a focus on the olfactory system\'s organization provide ideal tools for discovering deep ancestral relationships between the emotional systems of zebrafish and mammals. The review\'s focus is on the \"extended amygdala,\" which refers to subpallial amygdaloid territories including the central (autonomic) and the medial (olfactory) amygdala required for reproductive and social behaviors. Amphibians, sauropsids, and lungfish share many characteristics with the basic amygdala ground plan of mammals, as molecular and hodological studies have shown. Further exploration of the evolution of the amygdala in basally derived fish vertebrates requires researchers to test these \"tetrapod-based\" concepts. Historically, this has been a daunting task because the forebrains of basally derived fish vertebrates look very different from those of more familiar tetrapod ones. An extreme
case are ray-finned fish (Actinopterygii) like zebrafish because their telencephalon develops through a distinct outward-growing process called
eversion. To this day, scientists have struggled to determine how the everted telencephalon compares to non-actinopterygian vertebrates. Using the teleost zebrafish as a genetic model, comparative neurologists began to establish quantifiable molecular definitions that allow direct comparisons between ray-finned fish and tetrapods. In this review, I discuss how the most recent discovery of the zebrafish amygdala ground plan offers an opportunity to identify the developmental constraints of amygdala evolution and function. In addition, I explain how the zebrafish prethalamic eminence (PThE) topologically relates to the medial amygdala proper and the nucleus of the lateral olfactory tract (nLOT). In fact, I consider these previously misinterpreted olfactory structures the most critical missing evolutionary links between actinopterygian and tetrapod amygdalae. In this context, I will also explain why recognizing both the PThE and the nLOT is crucial to understanding the telencephalon
eversion. Recognizing these anatomical hallmarks allows direct comparisons of the amygdalae of zebrafish and mammals. Ultimately, the new concepts of the zebrafish amygdala will overcome current dogmas and reach a holistic understanding of amygdala circuits of cognition and emotion in actinopterygians.