Hitschfeld Eva M, Stamper Sarah A, Vonderschen Katrin, Fortune Eric S, Chacron Maurice J
Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA.
ILAR J. 2009;50(4):361-72. doi: 10.1093/ilar.50.4.361.
Weakly electric fishes have been an important model system in behavioral neuroscience for more than 40 years. These fishes use a specialized electric organ to produce an electric field that is typically below 1 volt/cm and serves in many behaviors including social communication and prey detection. Electrical behaviors are easy to study because inexpensive and widely available tools enable continuous monitoring of the electric field of individual or groups of interacting fish. Weakly electric fish have been routinely used in tightly controlled neurophysiological experiments in which the animal is immobilized using neuromuscular blockers (e.g., curare). Although experiments that involve immobilization are generally discouraged because it eliminates movement-based behavioral signs of pain and distress, many observable electrosensory behaviors in fish persist when the animal is immobilized. Weakly electric fish thus offer a unique opportunity to assess the effects of immobilization on behaviors including those that may reflect pain and distress. We investigated the effects of both immobilization and restraint on a variety of electrosensory behaviors in four species of weakly electric fishes and observed minor effects that were not consistent between the species tested or between particular behaviors. In general, we observed small increases and decreases in response magnitude to particular electrosensory stimuli. Stressful events such as asphyxiation and handling, however, resulted in significant changes in the fishes electrosensory behaviors. Signs of pain and distress include marked reductions in responses to electrosensory stimuli, inconsistent responses, and reductions in or complete cessation of the autogenous electric field.
四十多年来，弱电鱼一直是行为神经科学中的重要模型系统。这些鱼类利用专门的电器官产生通常低于1伏/厘米的电场，该电场在包括社会交流和猎物探测在内的许多行为中发挥作用。电行为易于研究，因为廉价且广泛可用的工具能够持续监测单个或相互作用的鱼群的电场。弱电鱼经常被用于严格控制的神经生理学实验中，在这些实验中，动物使用神经肌肉阻滞剂（如箭毒）进行固定。尽管通常不鼓励进行涉及固定的实验，因为它消除了基于运动的疼痛和痛苦行为迹象，但当动物被固定时，鱼的许多可观察到的电感觉行为仍然存在。因此，弱电鱼提供了一个独特的机会来评估固定对行为的影响，包括那些可能反映疼痛和痛苦的行为。我们研究了固定和束缚对四种弱电鱼的各种电感觉行为的影响，观察到的微小影响在测试的物种之间或特定行为之间并不一致。一般来说，我们观察到对特定电感觉刺激的反应幅度有小的增加和减少。然而，诸如窒息和处理等应激事件导致鱼的电感觉行为发生显著变化。疼痛和痛苦的迹象包括对电感觉刺激的反应明显减少、反应不一致以及自生电场的减少或完全停止。
