Neuroscience and Behavior Program, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003, USA.
J Neurophysiol. 2012 Mar;107(6):1621-31. doi: 10.1152/jn.00749.2011. Epub 2011 Dec 21.
Recent evidence shows that brain-derived steroids such as estrogens ("neuroestrogens") are controlled in a manner very similar to traditional neurotransmitters. The advent of in vivo microdialysis for steroids in songbirds has provided new information about the spatial and temporal dynamics of neuroestrogen changes in a region of the auditory cortex, the caudomedial nidopallium (NCM). Here, experiments using in vivo microdialysis demonstrate that neuroestradiol (E(2)) fluctuations occur within the auditory NCM during presentation of naturalistic auditory and visual stimuli in males but only to the presentation of auditory stimuli in females. These changes are acute (within 30 min) and appear to be specific to the NCM, because similar treatments elicit no changes in E(2) in a nearby mesopallial region or in circulating plasma. Further experiments coupling in vivo steroid microdialysis with extracellular recordings in NCM show that neuroestrogens rapidly boost auditory responses to song stimuli in females, similar to recent observations in males. We also find that the rapid actions of estradiol on auditory responses are fully mimicked by the cell membrane-impermeable estrogen biotinylestradiol, consistent with acute estrogen actions at the neuronal membrane. Thus we conclude that local and acute E(2) flux is regulated by convergent multimodal sensory input, and that this regulation appears to be sex-specific. Second, rapid changes in local E(2) levels in NCM have consequences for the modulation of auditory processing in females and males. Finally, the rapid actions of neuroestrogens on NCM auditory processing appear to be mediated by a nonclassical, membrane-bound estrogen receptor.
最近的证据表明，脑源性类固醇，如雌激素（“神经雌激素”），其控制方式与传统神经递质非常相似。类固醇在鸣禽体内活体微透析的出现，为听觉皮层中一个区域——尾侧中脑背核（NCM）的神经雌激素变化的时空动态提供了新信息。在这里，使用活体微透析的实验表明，在雄性中呈现自然听觉和视觉刺激时，神经雌二醇（E2）在听觉 NCM 中波动，但在雌性中仅在呈现听觉刺激时波动。这些变化是急性的（在 30 分钟内），似乎是 NCM 特有的，因为类似的处理不会引起附近中脑区域或循环血浆中 E2 的变化。进一步将活体类固醇微透析与 NCM 中的细胞外记录相结合的实验表明，神经雌激素可迅速增强雌性对歌曲刺激的听觉反应，与最近在雄性中观察到的情况相似。我们还发现，雌二醇对听觉反应的快速作用被细胞膜不可渗透的雌激素生物素雌二醇完全模拟，这与神经元膜上的急性雌激素作用一致。因此，我们得出结论，局部和急性 E2 流动受会聚多模态感觉输入的调节，并且这种调节似乎是性别特异性的。第二，NCM 中局部 E2 水平的快速变化会影响雌性和雄性听觉处理的调节。最后，神经雌激素对 NCM 听觉处理的快速作用似乎是通过非经典的、膜结合的雌激素受体介导的。
