Yao Jiwei, Li Qianwei, Li Xianping, Qin Han, Liang Shanshan, Liao Xiang, Chen Xiaowei, Li Weibing, Yan Junan
Department of Urology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Brain Research Center and State Key Laboratory of Trauma, Burns, and Combined Injury, Third Military Medical University, Chongqing, China.
Front Neurosci. 2019 Jun 25;13:663. doi: 10.3389/fnins.2019.00663. eCollection 2019.
Understanding the complex neural mechanisms controlling urinary bladder activity is an extremely important topic in both neuroscience and urology. Simultaneously recording of the bladder activity and neural activity in related brain regions will largely advance this field. However, such recording approach has long been restricted to anesthetized animals, whose bladder function and urodynamic properties are largely affected by anesthetics. In our recent report, we found that it is feasible to record bladder pressure (cystometry) and the related cortical neuron activity simultaneously in freely moving mice. Here, we aimed to demonstrate the use of this combined method in freely moving mice for recording the activity of the pontine micturition center (PMC), a more difficultly approachable small region deeply located in the brainstem and a more popularly studied hub for controlling bladder function. Interestingly, we found that the duration of urination events linearly correlated to the time course of neuronal activity in the PMC. We observed that the activities of PMC neurons highly correlated with spike-like increases in bladder pressure, reflecting bladder contractions. We also found that anesthesia evoked prominent changes in the dynamics of the Ca signals in the PMC during the bladder contraction and even induced the dripping overflow incontinence due to suppression of the neural activity in the PMC. In addition, we described in details both the system for cystometry in freely moving mice and the protocols for how to perform this combined method. Therefore, this work provides a powerful approach that enables the simultaneous measurement of neuronal activity of the PMC or any other brain sites and bladder function in freely behaving mice. This approach offers a promising possibility to examine the neural mechanisms underlying neurogenic bladder dysfunction.
了解控制膀胱活动的复杂神经机制是神经科学和泌尿学中极为重要的课题。同时记录膀胱活动和相关脑区的神经活动将极大地推动该领域的发展。然而，这种记录方法长期以来仅限于麻醉动物，其膀胱功能和尿动力学特性在很大程度上受麻醉剂影响。在我们最近的报告中，我们发现同时记录自由活动小鼠的膀胱压力（膀胱测压）和相关皮质神经元活动是可行的。在此，我们旨在展示这种联合方法在自由活动小鼠中用于记录脑桥排尿中枢（PMC）活动的应用，PMC是位于脑干深处一个更难接近的小区域，也是一个更广泛研究的控制膀胱功能的枢纽。有趣的是，我们发现排尿事件的持续时间与PMC中神经元活动的时间进程呈线性相关。我们观察到PMC神经元的活动与膀胱压力的尖峰样增加高度相关，反映了膀胱收缩。我们还发现麻醉在膀胱收缩期间引起PMC中钙信号动态的显著变化，甚至由于PMC中神经活动的抑制而导致滴漏性尿失禁。此外，我们详细描述了自由活动小鼠膀胱测压系统以及如何执行这种联合方法的方案。因此，这项工作提供了一种强大的方法，能够同时测量自由行为小鼠中PMC或任何其他脑区的神经元活动以及膀胱功能。这种方法为研究神经源性膀胱功能障碍的神经机制提供了一个有前景的可能性。
