Prestage Department of Poultry Science, Poultry Science Building, North Carolina State University, Raleigh, North Carolina, 27695.
College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, 27695.
Poult Sci. 2018 Mar 1;97(3):860-864. doi: 10.3382/ps/pex391.
The use of electroencephalograms (EEG) to study the avian brain relative to behavior was conducted as early as the 1960's. EEG readings, combined with visual cues, provide the ability to elucidate and correlate behaviors to neurological and physiological changes in a chicken. The use of EEG recordings in animal models require access to the brain to implant electrodes. Having the ability to observe EEG activity on sensible birds without surgical implantation could broaden the research in this area and give further insight related to the hen's state of awareness. The development, construction, and implementation of a minimally invasive EEG electrode placement method is described. After implementation, test animals were exposed to extreme environmental stressors as part of a concurrent depopulation methods study and EEG placement withstood the condition changes and corresponding animal physical activity. Sixteen white commercial laying hens had three monopolar 32-gauge needle electrodes inserted subcutaneously and secured to their head and body. Electrodes were attached to a pre-amplifier which transferred EEG signals to a laptop based recording system. Once the electrodes were in place, the hens were placed in individual treatment/observation chamber then various environmental stressors were applied. Verification that the observed brainwave activity was neural and not muscular was done using a photic stimulation validation test. Behavior observations were recorded to correlate sensible and insensible brainwave activity. The validation test and behavior observations demonstrated the method was successful in measuring EEG in sensible laying hens. The use of a non-surgical method for recording EEG will broaden research capabilities and enhance the understanding of a hen's response its environment, eliminate the need for invasive surgical procedures, and minimizes the confounding components of anesthesia, brain surgery, and recovery. With further refinements, the method could open new avenues in avian behavioral and physiological research.
早在 20 世纪 60 年代，就已经使用脑电图（EEG）来研究鸟类大脑与行为的关系。脑电图读数与视觉提示相结合，能够阐明和关联鸡的行为与神经和生理变化。在动物模型中使用 EEG 记录需要进入大脑植入电极。如果能够在无需手术植入的敏感鸟类身上观察 EEG 活动，那么这将拓宽该领域的研究，并进一步深入了解母鸡的意识状态。本文描述了一种微创 EEG 电极放置方法的开发、构建和实施。在实施后，测试动物被暴露于极端环境应激源中，作为同期淘汰方法研究的一部分，而 EEG 放置经受住了条件变化和相应的动物身体活动的考验。16 只白色商品产蛋母鸡的头部和身体皮下插入了三个单极 32 号针电极，并将其固定在位。电极连接到前置放大器，将 EEG 信号传输到基于笔记本电脑的记录系统。一旦电极就位，母鸡被放入单独的治疗/观察室，然后施加各种环境应激源。通过光刺激验证测试来验证观察到的脑电波活动是神经而不是肌肉的。记录行为观察结果，以关联敏感和不敏感的脑电波活动。验证测试和行为观察表明，该方法成功地测量了敏感产蛋母鸡的 EEG。使用非手术方法记录 EEG 将拓宽研究能力，并增强对母鸡对环境反应的理解，消除了对侵入性手术程序的需求，并最大限度地减少了麻醉、脑部手术和恢复的混杂因素。随着进一步的改进，该方法可能为鸟类行为和生理研究开辟新途径。
