Jackson Lillian R, Dumitrascu Mariam, Alward Beau A
Department of Psychology, University of Houston, Houston, USA.
Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, USA.
Sci Rep. 2025 Jan 2;15(1):84. doi: 10.1038/s41598-024-84188-4.
Aggression is ubiquitous among social species and can function to maintain social dominance hierarchies. The African cichlid fish Astatotilapia burtoni is an ideal study species for studying aggression due to their dominance hierarchy and robust behavioral repertoire. To further understand the potential sex differences in aggression in this species, we characterized aggression in male and female A. burtoni in a mirror assay. We then quantified neural activation patterns in brain regions of the social behavior network (SBN) to investigate if differences in behavior are reflected in the brain with immunohistochemistry by detecting the phosphorylated ribosome marker phospho-S6 ribosomal protein (pS6), a marker for neural activation. We found that A. burtoni perform both identical and sex-specific aggressive behaviors in response to a mirror assay. Females had greater pS6 immunoreactivity than males in the Vv (ventral part of the ventral telencephalon), a homolog of the lateral septum in mammals. Males but not females had higher pS6 immunoreactivity in the ATn after the aggression assay. The ATn (anterior tuberal nucleus) is a homolog of the ventromedial hypothalamus in mammals, which is strongly implicated in the regulation of aggression in males. Several regions also have higher pS6 immunoreactivity in negative controls than fish exposed to a mirror, implicating a role for inhibitory neural processes in suppressing aggression until a relevant stimulus is present. Male and female A. burtoni display both similar and different behavioral patterns in aggression in response to a mirror assay. There are also sex differences in the corresponding neural activation patterns in the SBN. In mirror males but not females, the ATn clusters with the POA, revealing a functional connectivity of these regions that is triggered in an aggressive context in males. These findings suggest that distinct neural circuitry underlie aggressive behavior in male and female A. burtoni, serving as a foundation for future work investigating the molecular and neural underpinnings of sex differences in behavior in this species to reveal fundamental insights into understanding aggression.
攻击行为在社会性物种中普遍存在，并且能够起到维持社会等级制度的作用。非洲丽鱼科鱼类伯氏妊丽鱼（Astatotilapia burtoni）因其等级制度和丰富的行为表现，是研究攻击行为的理想物种。为了进一步了解该物种攻击行为中潜在的性别差异，我们通过镜像试验对伯氏妊丽鱼雄性和雌性的攻击行为进行了特征描述。然后，我们通过检测磷酸化核糖体标记物磷酸化S6核糖体蛋白（pS6，一种神经激活标记物），运用免疫组织化学方法量化社会行为网络（SBN）脑区的神经激活模式，以研究行为差异是否在大脑中有所体现。我们发现，伯氏妊丽鱼在镜像试验中表现出相同和性别特异性的攻击行为。在腹侧端脑的腹侧部分（Vv，哺乳动物外侧隔的同源物），雌性的pS6免疫反应性高于雄性。在攻击试验后，雄性而非雌性在ATn（前结节核）中有更高的pS6免疫反应性。ATn（前结节核）是哺乳动物腹内侧下丘脑的同源物，与雄性攻击行为的调节密切相关。在阴性对照中，几个脑区的pS6免疫反应性也高于暴露于镜子的鱼，这表明抑制性神经过程在抑制攻击行为直到出现相关刺激方面发挥了作用。伯氏妊丽鱼雄性和雌性在镜像试验中的攻击行为表现出相似和不同的行为模式。在SBN相应的神经激活模式中也存在性别差异。在镜像试验中，雄性而非雌性的ATn与视前区（POA）聚集在一起，揭示了这些区域在雄性攻击情境中触发的功能连接。这些发现表明，不同的神经回路是伯氏妊丽鱼雄性和雌性攻击行为的基础，为未来研究该物种行为性别差异的分子和神经基础提供了基础，以揭示对理解攻击行为的基本见解。
