演題詳細
Symposium
闘争と階層の神経生物学
Neurobiology of aggression
開催日 | 2014/9/11 |
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時間 | 17:00 - 19:00 |
会場 | Room A(Main Hall) |
Chairperson(s) | 岡本 仁 / Hitoshi Okamoto (理化学研究所 脳科学総合研究センター / RIKEN Brain Science Institute, Japan) |
Genetic manipulations in the fruit fly fight club: how do amine neurons work?
- S1-A-2-1
- Edward Kravitz:1 Olga V Alekseyenko:1 Yick-Bun Chan:1
- 1:Dept Neurobiology, Harvard Medical School, Boston, MA, USA
Male and female fruit flies fight in same sex pairings. Learning and memory accompany these fights and lead to the establishment of "winner" and "loser" mentalities. In addition, males establish hierarchical relationships, while females do not. Amine neurons have been implicated in aggression in essentially all species of animals. In earlier studies, we genetically manipulated entire pools of serotonin, dopamine or octopamine (fly equivalent of norepinephrine) neurons (100-200 of each subtype), and generated interesting phenotypes. For example, we found that serotonin was not required to initiate aggression, but was involved in facilitating the transition to higher-level aggression during fights. Octopamine, appeared to be involved in the choice between courtship and aggression and dopamine deficiency generated hyperactive flies that did not interact in social behaviors with other flies. Recently, we developed an intersectional genetic technique that allows us to restrict the numbers of neurons of each subtype that can be manipulated. In this technique, we combine the binary Gal4/UAS system with the flp/frt recombinase technique. With this method, we identified single pairs of amine neurons specifically involved with aggression. These included a pair of 5HT-neurons (5HT-PLP neurons) that facilitated going to higher intensity levels in fights and two pairs of single DA neurons that held aggression in check. These neurons were "specialists" in that they had little or no effect on other behaviors that were known to be influenced by amines in fruit flies, like movement, diurnal rhythms and feeding. The 5HT-PLP neurons appear to contact neurons expressing 5HT1A receptors on their surfaces: activation of the latter neurons inhibits higher-level aggression. These results will be presented here along with the experimental plan being used to unravel at an identified neuron level the circuitry governing complex behaviors like aggression (supported by NIGMS).