Fujita Toshiyuki, Aoki Naoya, Mori Chihiro, Homma Koichi J, Yamaguchi Shinji
Department of Biological Sciences, Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan.
Department of Molecular Biology, Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo, Japan.
Front Neuroanat. 2025 Jan 15;19:1531200. doi: 10.3389/fnana.2025.1531200. eCollection 2025.
Animal personalities are stable, context-dependent behavioral differences. Associations between the personality of birds and polymorphisms in the dopamine receptor D4 (DRD4) gene have been repeatedly observed. In mammals, our understanding of the role of the dopamine (DA) system in higher cognitive functions and psychiatric disorders is improving, and we are beginning to understand the relationship between the neural circuits modulating the DA system and personality traits. However, to understand the phylogenetic continuity of the neural basis of personality, it is necessary to clarify the neural circuits that process personality in other animals and compare them with those in mammals. In birds, the DA system is anatomically and molecularly similar to that in mammals; however, the function of DRD4 remains largely unknown. In this study, we used chicks as model birds to reveal the expression regions of the DA neuron-related markers β, and , as well as other throughout the forebrain. We found that was selectively expressed in the mitral cells of the olfactory bulb (OB). Furthermore, a detailed comparison of the expression regions of DA neurons and in the OB revealed a cellular composition similar to that of mammals. Our findings suggest that the animal personality gene is important for olfactory information processing in birds, providing a new basis for comparing candidate neural circuits for personality traits between birds and mammals.
动物个性是稳定的、依赖于环境的行为差异。鸟类个性与多巴胺受体D4（DRD4）基因多态性之间的关联已被反复观察到。在哺乳动物中，我们对多巴胺（DA）系统在更高认知功能和精神疾病中的作用的理解正在不断深入，并且我们开始理解调节DA系统的神经回路与个性特征之间的关系。然而，为了理解个性神经基础的系统发育连续性，有必要阐明其他动物中处理个性的神经回路，并将它们与哺乳动物中的神经回路进行比较。在鸟类中，DA系统在解剖学和分子层面与哺乳动物中的相似；然而，DRD4的功能在很大程度上仍然未知。在本研究中，我们以雏鸡作为模式鸟类，来揭示DA神经元相关标志物β以及其他物质在前脑的表达区域。我们发现[具体物质]在嗅球（OB）的 mitral 细胞中选择性表达。此外，对OB中DA神经元和[具体物质]表达区域的详细比较揭示了一种与哺乳动物相似的细胞组成。我们的研究结果表明，动物个性基因[具体基因]对鸟类的嗅觉信息处理很重要，为比较鸟类和哺乳动物个性特征的候选神经回路提供了新的基础。
