College of Biosystems Engineering and Food Science (BEFS), Zhejiang University, Hangzhou, China.
College of Fisheries and Life Science, Dalian Ocean University, Dalian, China.
Front Endocrinol (Lausanne). 2024 Apr 30;15:1385575. doi: 10.3389/fendo.2024.1385575. eCollection 2024.
The brain regulates multiple physiological processes in fish. Despite this, knowledge about the basic structure and function of distinct brain regions in non-model fish species remains limited due to their diversity and the scarcity of common biomarkers. In the present study, four major brain parts, the telencephalon, diencephalon, mesencephalon and rhombencephalon, were isolated in largemouth bass, . Within these parts, nine brain regions and 74 nuclei were further identified through morphological and cytoarchitectonic analysis. Transcriptome analysis revealed a total of 7153 region-highly expressed genes and 176 region-specifically expressed genes. Genes related to growth, reproduction, emotion, learning, and memory were significantly overexpressed in the olfactory bulb and telencephalon (OBT). Feeding and stress-related genes were in the hypothalamus (Hy). Visual system-related genes were predominantly enriched in the optic tectum (OT), while vision and hearing-related genes were widely expressed in the cerebellum (Ce) region. Sensory input and motor output-related genes were in the medulla oblongata (Mo). Osmoregulation, stress response, sleep/wake cycles, and reproduction-related genes were highly expressed in the remaining brain (RB). Three candidate marker genes were further identified for each brain regions, such as neuropeptide FF () for OBT, pro-melanin-concentrating hormone () for Hy, vesicular inhibitory amino acid transporter () for OT, excitatory amino acid transporter 1 () for Ce, peripherin () for Mo, and isotocin neurophysin () for RB. Additionally, the distribution of seven neurotransmitter-type neurons and five types of non-neuronal cells across different brain regions were analyzed by examining the expression of their marker genes. Notably, marker genes for glutamatergic and GABAergic neurons showed the highest expression levels across all brain regions. Similarly, the marker gene for radial astrocytes exhibited high expression compared to other markers, while those for microglia were the least expressed. Overall, our results provide a comprehensive overview of the structural and functional characteristics of distinct brain regions in the largemouth bass, which offers a valuable resource for understanding the role of central nervous system in regulating physiological processes in teleost.
大脑调节鱼类的多种生理过程。尽管如此，由于非模式鱼类物种的多样性和常见生物标志物的稀缺，它们不同脑区的基本结构和功能的知识仍然有限。在本研究中，我们从大口黑鲈中分离出四大脑区，即端脑、间脑、中脑和后脑。在这些脑区中，通过形态学和细胞构筑学分析进一步鉴定了 9 个脑区和 74 个核。转录组分析共鉴定出 7153 个区域高表达基因和 176 个区域特异性表达基因。与生长、繁殖、情绪、学习和记忆相关的基因在嗅球和端脑（OBT）中显著过表达。与摄食和应激相关的基因在下丘脑（Hy）中。与视觉系统相关的基因主要富集在视顶盖（OT）中，而视觉和听觉相关的基因在小脑（Ce）区域广泛表达。感觉输入和运动输出相关的基因在延髓（Mo）中。与渗透调节、应激反应、睡眠/觉醒周期和繁殖相关的基因在剩余脑（RB）中高度表达。进一步为每个脑区鉴定了 3 个候选标记基因，如 OBT 中的神经肽 FF（）、Hy 中的促黑色素浓缩激素（）、OT 中的囊泡抑制性氨基酸转运体（）、Ce 中的兴奋性氨基酸转运体 1（）、Mo 中的 peripherin（）和 RB 中的催产素神经肽（）。此外，通过检测其标记基因的表达，分析了七种神经递质型神经元和五种类型的非神经元细胞在不同脑区的分布。值得注意的是，谷氨酸能和 GABA 能神经元的标记基因在所有脑区的表达水平最高。同样，放射状星形胶质细胞的标记基因表达水平也高于其他标记基因，而小胶质细胞的标记基因表达水平最低。总的来说，我们的研究结果提供了大口黑鲈不同脑区结构和功能特征的全面概述，为理解中枢神经系统在调节硬骨鱼类生理过程中的作用提供了有价值的资源。
