GIGA Neurosciences, University of Liège, B-4000, Liège, Belgium.
Department of Psychology, University of Maryland, College Park, MD, USA.
Behav Brain Res. 2021 Jul 23;410:113315. doi: 10.1016/j.bbr.2021.113315. Epub 2021 Apr 24.
Aromatase converts androgens into estrogens in the brain of vertebrates including humans. This enzyme is also expressed in other tissues where its action may result in negative effects on human health (e.g., promotion of tumor growth). To prevent these effects, aromatase inhibitors were developed and are currently used to block human estrogen-dependent tumors. In vertebrates including quail, aromatase is expressed in a highly conserved set of interconnected brain nuclei known as the social behavior network. This network is directly implicated in the expression of a large range of social behaviors. The primary goal of this study was to characterize in Japanese quail the potential impact of brain aromatase on sexual behavior, aggressiveness and social motivation (i.e., tendency to approach and stay close to conspecifics). An additional goal was to test the feasibility and effectiveness of long-term delivery of an aromatase inhibitor directly into the third ventricle via Alzet™ osmotic minipumps using male sexual behavior as the aromatase dependent measure. We demonstrate that this mode of administration results in the strongest inhibition of both copulatory behavior and sexual motivation ever observed in this species, while other social behaviors were variably affected. Sexual motivation and the tendency to approach a group of conspecifics including females clearly seem to depend on brain aromatase, but the effects of central estrogen production on aggressive behavior and on the motivation to approach males remain less clear.
在包括人类在内的脊椎动物的大脑中，芳香酶将雄激素转化为雌激素。这种酶也在其他组织中表达，其作用可能对人类健康产生负面影响（例如促进肿瘤生长）。为了防止这些影响，开发了芳香酶抑制剂，目前用于阻断人类雌激素依赖性肿瘤。在包括鹌鹑在内的脊椎动物中，芳香酶在一组高度保守的相互连接的脑核中表达，称为社会行为网络。该网络直接涉及多种社会行为的表达。本研究的主要目标是在日本鹌鹑中描述大脑芳香酶对性行为、攻击性和社交动机（即接近和亲近同种个体的倾向）的潜在影响。另一个目标是测试通过 Alzet™渗透微型泵将芳香酶抑制剂直接递送至第三脑室的长期给药的可行性和有效性，以雄性性行为作为芳香酶依赖性的测量指标。我们证明，这种给药方式导致了该物种中观察到的最强的交配行为和性动机抑制，而其他社会行为则受到不同程度的影响。性动机和接近包括雌性在内的一群同种个体的倾向似乎明显取决于大脑中的芳香酶，但中枢雌激素产生对攻击性行为和接近雄性的动机的影响仍不太清楚。
