NEUROETHOLOGICAL STUDY OF SALMON HOMING

姬鲑鱼（红鲑的湖泊形式，Oncorhynchus nerka ;在北美被称为kokanee）通过中善寺湖（尼科，日本）迁移，并在成熟时返回他们的家乡河流。在这项研究中，我们研究，作为一个步骤，了解嗅觉机制鲑鱼归巢，（1）脑电图（EEG）的反应，从嗅球到各种河流沃茨和（2）的行为能力，选择回家的水，使用一个新开发的Y-迷宫。作为结果，我们发现，（a）从电生理学分析的姬鲑鱼可以区分两个相邻的河流（家乡河和非家乡河）的口处的沃茨，（B）从实验行为分析的鱼喜欢家乡水比非家乡水，和（c）这种家乡水的偏好以及上游的行为被严重破坏后，损伤的嗅觉器官。(d)因此，本研究为鲑鱼归巢的实验行为分析开辟了一条新的途径。

Hime salmon (lacustrine form of sockeye salmon, Oncorhynchus nerka ; known as kokanee in North America) migrate through Lake Chuzenji (Nikko, Tochigi Prefecture, Japan), and return to their home river when matured. In this study we examined, as a step towards understanding the olfactory mechanism for salmon homing, (1) electroencephalographic (EEG) response from the olfactory bulb to various river waters and (2) behavioral ability to choose the home water by using a newly developed Y-maze. As the results we found that (a) from electrophysiological analyses the hime salmon can discriminate between waters at the mouths of two neighboring rivers (home river and non-home river), (b) from experimental behavioral analyses the fish prefer the home water to the non-home water, and (c) this preference of the home water as well as the upstream-going behavior are severely damaged after lesioning the olfactory sense organ. (d) Thus, the present study opens a new way for experimental behavioral analyses of the salmon homing.