Lower urinary tract or voiding disorders are prevalent across all ages and affect >40% of adults over 40 years old, leading to decreased quality of life and high health care costs. The pontine micturition center (PMC; i.e., Barrington's nucleus) contains a large population of neurons that localize the stress-related neuropeptide, corticotropin-releasing hormone (CRH) and project to neurons in the spinal cord to regulate micturition. How the PMC and CRH-expressing neurons in the PMC control volitional micturition is of critical importance for human voiding disorders. To investigate the specific role of CRH in the PMC, neurons in the PMC-expressing CRH were optogenetically activated during in vivo cystometry in unanesthetized mice of either sex. Optogenetic activation of CRH-PMC neurons led to increased intermicturition interval and voided volume, similar to the altered voiding phenotype produced by social stress. Female mice showed a significantly more pronounced phenotype change compared with male mice. These effects were eliminated by CRH-receptor 1 antagonist pretreatment. Optogenetic inhibition of CRH-PMC neurons led to an altered voiding phenotype characterized by more frequent voids and smaller voided volumes. Last, in a cyclophosphamide cystitis model of bladder overactivity, optogenetic activation of CRH-PMC neurons returned the voiding pattern to normal. Collectively, our findings demonstrate that CRH from PMC spinal-projecting neurons has an inhibitory function on micturition and is a potential therapeutic target for human disease states, such as voiding postponement, urinary retention, and underactive or overactive bladder.

SIGNIFICANCE STATEMENT The pontine micturition center (PMC), which is a major regulator of volitional micturition, is neurochemically heterogeneous, and excitatory neurotransmission derived from PMC neurons is thought to mediate the micturition reflex. In the present study, using optogenetic manipulation of CRH-containing neurons in double-transgenic mice, we demonstrate that CRH, which is prominent in PMC-spinal projections, has an inhibitory function on volitional micturition. Moreover, engaging this inhibitory function of CRH can ameliorate bladder hyperexcitability induced by cyclophosphamide in a model of cystitis. The data underscore CRH as a novel target for the treatment of voiding dysfunctions, which are highly prevalent disease processes in children and adults.

下尿路或排尿障碍在所有年龄段都很普遍，影响超过 40% 的 40 岁以上的成年人，导致生活质量下降和医疗保健费用高昂。脑桥排尿中心（PMC；即巴林顿核）包含大量神经元，这些神经元定位与压力相关的神经肽、促肾上腺皮质激素释放激素 (CRH)，并投射到脊髓中的神经元以调节排尿。PMC 和 PMC 中表达 CRH 的神经元如何控制自主排尿对于人类排尿障碍至关重要。为了研究 CRH 在 PMC 中的具体作用，表达 PMC 的 CRH 中的神经元在 体内期间被光遗传学激活任何性别的未麻醉小鼠的膀胱测压术。CRH-PMC 神经元的光遗传学激活导致间歇性排尿间隔和排尿量增加，类似于社会压力产生的排尿表型改变。与雄性小鼠相比，雌性小鼠表现出明显更明显的表型变化。这些影响被 CRH 受体 1 拮抗剂预处理消除。CRH-PMC 神经元的光遗传学抑制导致排尿表型改变，其特征是更频繁的排尿和更小的排尿体积。最后，在膀胱过度活动的环磷酰胺膀胱炎模型中，CRH-PMC 神经元的光遗传学激活使排尿模式恢复正常。集体，

重要性声明脑桥排尿中心 (PMC) 是意志排尿的主要调节器，在神经化学上是异质的，来自 PMC 神经元的兴奋性神经传递被认为介导了排尿反射。在本研究中，我们对双转基因小鼠中含有 CRH 的神经元进行光遗传学操作，证明了在 PMC 脊髓投射中突出的 CRH 对自主排尿具有抑制作用。此外，利用 CRH 的这种抑制功能可以改善由环磷酰胺在膀胱炎模型中引起的膀胱过度兴奋。数据强调 CRH 是治疗排尿功能障碍的新目标，这是儿童和成人中非常普遍的疾病过程。