Nicol Alister U, Perentos Nicholas, Martins Amadeu Q, Morton A Jennifer
Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
Physiol Behav. 2016 Sep 1;163:258-266. doi: 10.1016/j.physbeh.2016.05.028. Epub 2016 May 17.
Rumination is a precisely timed process that occupies a large part of a sheep's day. The complex motor coordination required to chew and swallow means that quantification of rumination may provide a surrogate marker for effective motor function. Here, data from 24h in vivo electrophysiological recordings, collected as part of an earlier study, were reanalysed for chewing- and swallowing-related activity. The electroencephalographic (EEG) and electromyographic (EMG) data were collected from sheep with surgically-implanted electrodes. An algorithm was designed to detect coordinated, rhythmic muscle activity. This could distinguish episodes of eating from those of rumination. Normal sheep spent 29% of their time ruminating. Rumination comprised ~40s bouts of regular (1.7s(-1)) chewing interspersed by 6.5s intervals during which time no chewing took place. Eating was significantly less regular than rumination, with quicker chewing (2.7s(-1)). Biomarkers for measuring progression of disease would be invaluable for studying neurodegenerative disease such as Huntington's disease (HD). To test the feasibility of using rumination as such a biomarker, we also made recordings from two neurologically impaired sheep. These showed deviations from the pattern of rumination and eating seen in normal sheep. This validates not only our use of rumination as a measure of normal motor function, but also as a surrogate biomarker for measuring motor dysfunction in impaired sheep.
反刍是一个有精确时间安排的过程，占据了绵羊一天中的大部分时间。咀嚼和吞咽所需的复杂运动协调意味着，反刍的量化可能为有效的运动功能提供一个替代指标。在这里，作为早期研究的一部分收集的24小时体内电生理记录数据，被重新分析用于与咀嚼和吞咽相关的活动。脑电图（EEG）和肌电图（EMG）数据是从植入了手术电极的绵羊身上收集的。设计了一种算法来检测协调的、有节奏的肌肉活动。这可以区分进食和反刍的阶段。正常绵羊花费约29%的时间进行反刍。反刍由约40秒的规律（约1.7次/秒）咀嚼组成，其间穿插着约6.5秒的无咀嚼间隔。进食的规律性明显低于反刍，咀嚼速度更快（约2.7次/秒）。用于测量疾病进展的生物标志物对于研究亨廷顿舞蹈症（HD）等神经退行性疾病将非常宝贵。为了测试使用反刍作为这样一种生物标志物的可行性，我们还对两只神经功能受损的绵羊进行了记录。这些记录显示出与正常绵羊的反刍和进食模式存在偏差。这不仅验证了我们将反刍用作正常运动功能指标的做法，也验证了将其作为测量受损绵羊运动功能障碍的替代生物标志物的做法。
