To clarify both molecular/neural basis and brain information processing underlying social interactions
in vertebrates, we have focused medaka fish and established a novel experimental system to induce medaka
schooling-like behavior. The two adult fish tended to swim maintaining a set distance (2 to 4-cm) to each other,
under a condition where the two fish exhibited the optomotor response (OMR) simultaneously. The behavior
was observed selectively in conspecific pairs. Their relative positions were changing frequently, suggesting that
there is no apparent leader in the schooling-like behavior. Generally, when animal group (fish school, bird flock,
and herd) moves, the members maintain a set distance to their nearest neighbors and their relative positions are
not stable. Thus analysis of this medaka system might help us to understand neural basis of animal grouping
behavior. Furthermore to identify candidate genes involved in medaka social interactions, we searched for
neuropeptides in the telencephalon and hypothalamus, which are thought to be important for vertebrate social
interactions. Here, we used direct matrix-assisted laser desorption/ionization with time-of-flight mass
spectrometry (MALDI-TOF MS) and detected the presence of several neuropeptides from the two brain regions.
In situ hybridization analysis confirmed that gamma-prepro-tachykinin gene encoding a neuropeptide, Substance
P, was expressed preferentially in the two regions of the medaka brain.
各種検索
サポート
ヘルプ