Trannoy Severine, Chowdhury Budhaditya, Kravitz Edward A
Department of Neurobiology, Harvard Medical School;
Department of Neurobiology, Harvard Medical School.
J Vis Exp. 2015 Dec 30(106):e53395. doi: 10.3791/53395.
Aggressive behavior in Drosophila melanogaster is composed of the sequential expression of stereotypical behavioral patterns (for analysis see (1)). This complex behavior is influenced by genetic, hormonal and environmental factors. As in many organisms, previous fighting experience influences the fighting strategy of flies and the outcome of later contests: losing a fight increases the probability of losing later contests, revealing "loser" effects that likely involve learning and memory (2-4). The learning and memory that accompanies expression of complex social behaviors like aggression, is sensitive to pre-test handling of animals (5,6). Many experimental procedures are used in different laboratories to study aggression (7-9), however, no routinely used protocol that excludes handling of flies is currently available. Here, we report a new behavioral apparatus that eliminates handling of flies, using instead their innate negative geotactic responses to move animals into or out of fighting chambers. In this protocol, small circular fight arenas containing a food cup are divided into two equal halves by a removable plastic slider prior to introduction of flies. Flies enter chambers from their home isolation vials via sliding chamber doors and geotaxis. Upon removal of plastic sliders, flies are free to interact. After specified time periods, flies are separated again by sliders for subsequent experimentation. All of this is done easily without handling of individual flies. This apparatus offers a novel approach to study aggression and the associated learning and memory, including the formation of "loser" effects in fly fights. In addition, this new general-purpose behavioral apparatus can be employed to study other social behaviors of flies and should, in general, be of interest for investigating experience-related changes in fundamental behavioral processes.
黑腹果蝇的攻击行为由一系列刻板行为模式的顺序表达组成（分析见参考文献(1)）。这种复杂行为受到遗传、激素和环境因素的影响。与许多生物体一样，先前的战斗经验会影响果蝇的战斗策略和后续争斗的结果：输掉一场战斗会增加在后续争斗中失败的概率，这揭示了可能涉及学习和记忆的“失败者”效应（参考文献(2 - 4)）。伴随攻击等复杂社会行为表达的学习和记忆，对动物在测试前的处理很敏感（参考文献(5,6)）。不同实验室使用了许多实验程序来研究攻击行为（参考文献(7 - 9)），然而，目前尚无常规使用的排除果蝇处理的方案。在此，我们报告一种新的行为装置，该装置利用果蝇天生的负趋地性反应将其移入或移出战斗室，从而避免了对果蝇的处理。在该方案中，在引入果蝇之前，将装有食物杯的小型圆形战斗 arena 用可移动的塑料滑块分成两个相等的部分。果蝇通过滑动室门和趋地性从其家隔离小瓶进入室中。移除塑料滑块后，果蝇可以自由互动。在指定时间段后，果蝇再次被滑块分开以便后续实验。所有这些操作都很容易完成，无需处理单个果蝇。该装置为研究攻击行为以及相关的学习和记忆提供了一种新方法，包括果蝇战斗中“失败者”效应的形成。此外，这种新型通用行为装置可用于研究果蝇的其他社会行为，总体而言，对于研究基本行为过程中与经验相关的变化应该是有意义的。
