Jun James J, Longtin André, Maler Leonard
Department of Physics, University of Ottawa; Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neural Dynamics, University of Ottawa;
Department of Physics, University of Ottawa; Department of Cellular and Molecular Medicine, University of Ottawa; Centre for Neural Dynamics, University of Ottawa.
J Vis Exp. 2014 Mar 6(85):50962. doi: 10.3791/50962.
Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals' access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal's body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal's body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors.
长期行为跟踪可以捕捉并量化动物的自然行为，包括那些不常发生的行为。探索和社交互动等行为，通过观察无束缚、自由活动的动物能得到最佳研究。弱电鱼（WEF）通过发出电器官放电（EOD）来展现易于观察的探索和社交行为。在此，我们描述三种有效的技术，用于长时间同步测量自由游动的弱电鱼的EOD、身体位置和姿势。首先，我们描述在一个隔离室内构建实验水箱，该隔离室旨在阻挡光、声和振动等外部感官刺激源。水族箱被分隔开以容纳四个测试样本，自动门可远程控制动物进入中央区域。其次，我们描述一种精确可靠的实时EOD定时测量方法，用于自由游动的弱电鱼。由动物身体运动引起的信号失真通过空间平均和时间处理阶段进行校正。第三，我们描述一种水下近红外成像装置，用于观察不受干扰的夜间动物行为。红外光脉冲用于在长时间记录过程中同步视频和生理信号之间的时间。我们的自动跟踪软件能在水生场景中可靠地测量动物的身体位置和姿势。综合起来，这些技术能够以可靠且精确的方式长期观察自由游动的弱电鱼的自发行为。我们相信，通过将其他水生动物的生理信号与探索或社交行为相关联，我们的方法可类似地应用于它们的研究。
