School of Public Health, SUNY at Albany, Rensselaer, New York.
Wadsworth Center, New York State Department of Health, Albany, New York; and School of Public Health, SUNY at Albany, Rensselaer, New York.
Am J Physiol Renal Physiol. 2014 Aug 15;307(4):F485-97. doi: 10.1152/ajprenal.00059.2014. Epub 2014 Jul 2.
The external urethral sphincter muscle (EUS) plays an important role in urinary function and often contributes to urinary dysfunction. EUS study would benefit from methodology for longitudinal recording of electromyographic activity (EMG) in unanesthetized animals, but this muscle is a poor substrate for chronic intramuscular electrodes, and thus the required methodology has not been available. We describe a method for long-term recording of EUS EMG by implantation of fine wires adjacent to the EUS that are secured to the pubic bone. Wires pass subcutaneously to a skull-mounted plug and connect to the recording apparatus by a flexible cable attached to a commutator. A force transducer-mounted cup under a metabolic cage collected urine, allowing recording of EUS EMG and voided urine weight without anesthesia or restraint. Implant durability permitted EUS EMG recording during repeated (up to 3 times weekly) 24-h sessions for more than 8 wk. EMG and voiding properties were stable over weeks 2-8. The degree of EUS phasic activity (bursting) during voiding was highly variable, with an average of 25% of voids not exhibiting bursting. Electrode implantation adjacent to the EUS yielded stable EMG recordings over extended periods and eliminated the confounding effects of anesthesia, physical restraint, and the potential for dislodgment of the chronically implanted intramuscular electrodes. These results show that micturition in unanesthetized, unrestrained rats is usually, but not always, associated with EUS bursting. This methodology is applicable to studying EUS behavior during progression of gradually evolving disease and injury models and in response to therapeutic interventions.
尿道外括约肌（EUS）在尿功能中起着重要作用，经常导致尿功能障碍。EUS 的研究将受益于对未麻醉动物进行肌电图（EMG）纵向记录的方法，但该肌肉是慢性肌内电极的不良基质，因此所需的方法尚未出现。我们描述了一种通过将细电线植入靠近 EUS 并固定在耻骨上的方法来长期记录 EUS EMG 的方法。电线通过皮下穿过颅骨安装的插头，并通过连接到换向器的柔性电缆连接到记录仪器。代谢笼下装有一个装有称重传感器的杯子，可收集尿液，在不进行麻醉或限制的情况下记录 EUS EMG 和排尿量。植入物的耐用性允许在 8 周以上的时间内，每周重复进行多次（多达 3 次）24 小时的 EUS EMG 记录。EMG 和排尿性能在第 2-8 周期间保持稳定。排尿期间 EUS 相位活动（爆发）的程度变化很大，平均有 25%的排尿不显示爆发。在 EUS 附近植入电极可在较长时间内稳定地记录 EMG，并消除麻醉、物理束缚以及潜在的慢性植入肌内电极移位的混杂影响。这些结果表明，在未麻醉、未束缚的大鼠中，排尿通常（但并非总是）与 EUS 爆发有关。这种方法适用于研究逐渐发展的疾病和损伤模型中 EUS 行为的变化，以及对治疗干预的反应。
