Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States; Center for the Integrative Study of Animal Behavior, Indiana University, 409 N. Park Ave, Bloomington, IN 47405, United States.
Department of Biology, Indiana University, 1001 E 3(rd) St., Bloomington, IN 47405, United States.
Gen Comp Endocrinol. 2024 Sep 1;355:114549. doi: 10.1016/j.ygcen.2024.114549. Epub 2024 May 24.
The production of communication signals can be modulated by hormones acting on the brain regions that regulate these signals. However, less is known about how signal perception is regulated by hormones. The electrocommunication signals of weakly electric fishes are sexually dimorphic, sensitive to hormones, and vary across species. The neural circuits that regulate the production and perception of these signals are also well-characterized, and electric fishes are thus an excellent model to examine the neuroendocrine regulation of sensorimotor mechanisms of communication. We investigated (1) whether steroid-related genes are expressed in sensory brain regions that process communication signals; and (2) whether this expression differs across sexes and species that have different patterns of sexual dimorphism in their signals. Apteronotus leptorhynchus and Apteronotus albifrons produce continuous electric organ discharges (EODs) that are used for communication. Two brain regions, the electrosensory lateral line lobe (ELL) and the dorsal torus semicircularis (TSd), process inputs from electroreceptors to allow fish to detect and discriminate electrocommunication signals. We used qPCR to quantify the expression of genes for two androgen receptors (ar1, ar2), two estrogen receptors (esr1, esr2b), and aromatase (cyp19a1b). Four out of five steroid-related genes were expressed in both sensory brain regions, and their expression often varied between sexes and species. These results suggest that expression of steroid-related genes in the brain may differentially influence how EOD signals are encoded across species and sexes, and that gonadal steroids may coordinately regulate central circuits that control both the production and perception of EODs.
通讯信号的产生可以受到作用于调节这些信号的大脑区域的激素的调制。然而，对于激素如何调节信号感知知之甚少。弱电鱼的电通讯信号具有性别二态性，对激素敏感，并且在物种间存在差异。调节这些信号产生和感知的神经回路也得到了很好的描述，因此电鱼是研究通讯感觉运动机制的神经内分泌调节的极好模型。我们研究了（1）与类固醇相关的基因是否在处理通讯信号的感觉大脑区域中表达；以及（2）这种表达是否因具有不同信号性别二态性模式的物种而有所不同。Apteronotus leptorhynchus 和 Apteronotus albifrons 产生用于通讯的连续电器官放电 (EOD)。两个大脑区域，即电感觉侧线叶 (ELL) 和背侧环管半规管 (TSd)，处理来自电感受器的输入，使鱼类能够检测和区分电通讯信号。我们使用 qPCR 来定量两种雄激素受体 (ar1, ar2)、两种雌激素受体 (esr1, esr2b) 和芳香酶 (cyp19a1b) 的基因表达。五种类固醇相关基因中的四种在两个感觉大脑区域中均有表达，其表达通常在性别和物种之间存在差异。这些结果表明，大脑中类固醇相关基因的表达可能会以不同的方式影响 EOD 信号在物种和性别间的编码方式，并且性腺类固醇可能协调调节控制 EOD 产生和感知的中枢回路。
