Roh Mootaek, McHugh Thomas J, Lee Kyungmin
Department of Anatomy, Brain Science & Engineering Institute, Behavioral Neural Circuitry and Physiology Laboratory, Kyungpook National University Graduate School of Medicine, 2-101, Dongin-dong, Jung-gu, Daegu, 700-842, South Korea.
Laboratory for Circuit and Behavioral Physiology, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198, Japan.
Mol Brain. 2015 Oct 12;8(1):61. doi: 10.1186/s13041-015-0152-8.
To investigate the relationship between neural function and behavior it is necessary to record neuronal activity in the brains of freely behaving animals, a technique that typically involves tethering to a data acquisition system. Optimally this approach allows animals to behave without any interference of movement or task performance. Currently many laboratories in the cognitive and behavioral neuroscience fields employ commercial motorized commutator systems using torque sensors to detect tether movement induced by the trajectory behaviors of animals.
In this study we describe a novel motorized commutator system which is automatically controlled by video tracking. To obtain accurate head direction data two light emitting diodes were used and video image noise was minimized by physical light source manipulation. The system calculates the rotation of the animal across a single trial by processing head direction data and the software, which calibrates the motor rotation angle, subsequently generates voltage pulses to actively untwist the tether. This system successfully provides a tether twist-free environment for animals performing behavioral tasks and simultaneous neural activity recording.
To the best of our knowledge, it is the first to utilize video tracking generated head direction to detect tether twisting and compensate with a motorized commutator system. Our automatic commutator control system promises an affordable and accessible method to improve behavioral neurophysiology experiments, particularly in mice.
为了研究神经功能与行为之间的关系，有必要记录自由活动动物大脑中的神经元活动，这一技术通常涉及与数据采集系统相连。理想情况下，这种方法能让动物在不受运动或任务执行干扰的情况下活动。目前，认知和行为神经科学领域的许多实验室都采用商业电动换向器系统，该系统使用扭矩传感器来检测动物轨迹行为引起的系绳运动。
在本研究中，我们描述了一种由视频跟踪自动控制的新型电动换向器系统。为了获得准确的头部方向数据，使用了两个发光二极管，并通过物理光源操作将视频图像噪声降至最低。该系统通过处理头部方向数据来计算动物在单次试验中的旋转，校准电机旋转角度的软件随后会生成电压脉冲以主动解开系绳。该系统成功地为执行行为任务和同时进行神经活动记录的动物提供了无系绳扭转的环境。
据我们所知，这是首次利用视频跟踪生成的头部方向来检测系绳扭转，并通过电动换向器系统进行补偿。我们的自动换向器控制系统有望提供一种经济实惠且易于使用的方法来改进行为神经生理学实验，尤其是在小鼠实验中。
