Comparative neuro-behavioral study on auditory cognition in songbirds and fish

本研究以虎皮鹦鹉为研究对象，在一个消声箱中，将雄性虎皮鹦鹉的鸣叫录音暴露给雌性虎皮鹦鹉，探讨了虎皮鹦鹉鸣禽交流的听觉认知脑机制，以及金鱼对斜平行线振荡条纹的认知。我们计算了雌性大脑中Zenk-IR（免疫反应）细胞的数量，作为歌曲刺激激活神经元的指示。结果，我们发现密集的免疫反应神经元在NCM（新纹状体尾内侧部）。歌曲越复杂，表达Zenk蛋白的神经元就越多。另外，在靠近NCM的中间新纹状体（neostriatum intermedium pars lateralis，NIL）和鹦鹉脑前部的L1、L3区、尾内侧新纹状体（caudomedial neostriatum）也观察到了鸣唱激活神经元。在后续的研究中，我们发现金鱼可以同时使用方向策略和角度策略来区分两个不同角度/方向的倾斜条纹图案。这意味着金鱼有两种策略，角度和方向，以区分两条斜线。如果是这样的话，每一条金鱼可能会使用角度或方向作为自己的首选策略。然而，我们不能证明金鱼优先使用一种策略。

We investigated the auditory cognitive brain mechanism of songbird communication in budgerigars, and the cognition of oscillatory stripes of oblique parallel lines in goldfish.In the study of budgerigars, tape-recorded male songs were exposed to each adult female in a sound attenuated box. We counted the number of Zenk-IR (immunoreactive) cells in the female brains, as an indication of activated neurons by the song stimulation. As a result, we found dense immunoreactive neurons in the NCM (neostriatum caudale pars medialis). The more songs were complex, the more were the Zenk protein expressed neurons. Other song-activated neurons were observed in the NIL (neostriatum intermedium pars lateralis) near by the NCM, and field L1, field L3, caudomedial neostriatum in anterior areas of the budgerigar brain.The research of goldfish cognitive behavior was firstly carried out to study whether they can discriminate striped patterns made of horizontal lines out of vertical ones, and we found that they can discriminate those directions. In the succeeding studies, we indicated that goldfish can use both the direction strategy and angle strategy to discriminate between two obliquely striped patterns with different angle/direction. This means that goldfish has two strategies, angle and direction, to discriminate two oblique lines. If so, each goldfish might use the angle or direction as an own preferred strategy. However, we could not show the fact indicating that goldfish have priority to use one strategy over the other.