Dataset for: Testosterone-induced neuroendocrine changes in the medial preoptic area precede song activation and plasticity in song control nuclei of female canaries

Testosterone plays a key role in the control of seasonal changes in singing behavior and its underlying neural circuitry. After administration of exogenous testosterone, song quality and song control nuclei volumes change over the course of weeks, but song rate increases within days. The medial preoptic nucleus (POM) controls sexual motivation and testosterone action in POM increases sexually motivated singing. Here, we investigated the time course of testosterone action in the song control nuclei and POM, at the gross anatomical and cellular level. Photosensitive female canaries were injected with BrdU to label newborn neurons. One day later they were transferred to a long day photoperiod and implanted with testosterone-filled or empty implants. Brains and blood were collected 1, 2, 9 or 21 days later. Testosterone increased POM volume within one day, whereas the volume of song control nuclei increased significantly only on day 21 even if a trend was already observed for HVC on day 9. The density of newborn neurons in HVC, labeled by Bromodeoxyuridine (BrdU) and doublecortin, was increased by testosterone on days 9 and 21 although a trend was already detectable on day 2. In POM testosterone increased the number and size of aromatase-immunoreactive neurons already after one day. This rapid action of testosterone in POM supports its proposed role in controlling singing motivation. Although testosterone increased the number of newborn neurons in HVC rapidly (9, possibly 2 days), it is unlikely that these new neurons affect singing behavior before they mature and integrate into functional circuits.

睾酮（Testosterone）在调控鸣唱行为的季节性变化及其潜在神经环路中发挥关键作用。给动物施加外源性睾酮（Testosterone）后，鸣唱质量与鸣唱控制核团体积会在数周内发生改变，而鸣唱频率会在数日内上升。内侧视前核（medial preoptic nucleus, POM）调控性动机，且该核团内的睾酮作用可增强受性动机驱动的鸣唱行为。本研究探究了睾酮在鸣唱控制核团与内侧视前核中发挥作用的时间进程，涵盖大体解剖与细胞两个层面。
研究人员对感光性雌性金丝雀注射溴脱氧尿苷（Bromodeoxyuridine, BrdU）以标记新生神经元。1天后将其转移至长光照周期环境，并植入填充睾酮或空白的缓释植入物。分别在术后1、2、9或21天采集脑组织与血液样本。
睾酮可在1天内增大内侧视前核的体积；而鸣唱控制核团的体积仅在第21天才出现显著增加，即便第9天时已观察到HVC核团体积上升的趋势。通过溴脱氧尿苷（BrdU）与双皮质素（doublecortin）标记的HVC核团内新生神经元密度，在第9天与第21天被睾酮显著提升，而在第2天即可检测到上升趋势。在POM中，睾酮可在1天内即增加芳香化酶免疫反应神经元的数量与体积。
睾酮在POM中的这一快速作用，支持了其在调控鸣唱动机中发挥既定作用的假说。尽管睾酮可快速提升HVC核团内新生神经元的数量（第9天，甚至可能在第2天），但这些新生神经元在成熟并整合入功能环路之前，不太可能对鸣唱行为产生影响。