Intraspinal circuits supporting synergy between the bladder and urethral sphincter in mice

项目总结 逼尿肌括约肌协同失调(DSD)是一种主要的泌尿系问题，导致排尿效率低下，尿量增加 脊髓损伤(SCI)后残余尿量和高膀胱内压。直到最近， 大多数关于外括约肌与外括约肌之间协调的脊髓机制的研究 虽然在临床实践中，DSD更多地发生在雄性大鼠身上，但雌性大鼠进行了膀胱(BL)试验。 此外，下尿路(LUT)的解剖和功能(LUT)中的性别二型性表现出差异。 在男性和女性的脊髓神经回路中。随着遗传修饰和光遗传技术的发展 技术LUT功能障碍的小鼠模型正变得比大鼠更有用。因此，在 建议项目“支持膀胱和尿道括约肌之间协同作用的椎管内回路” 我们将使用转基因小鼠进行电生理、光遗传学、免疫组织化学、 脊髓环路参与膀胱相互作用的药理学和解剖学研究 以及脊柱完整动物和脊髓损伤后的外尿道括约肌(EUS)。 我们将在体内和体外实验中检验几个假说。在乌拉坦麻醉的动物中 无论男女，我们将确定脊髓排尿调节以及对照和脊髓损伤的功能差异。 老鼠。雄性和雌性动物也将被用来确定与LUT相关的假设性二型性 慢性脊髓损伤后脊髓环路及其可塑性。使用电刺激腰椎协调功能 中心(LSCC)，我们最近在L3/L4脊柱节段发现，我们将测试外部 命令可以启动排空。使用跨突触病毒标记，我们将追踪参与 EUS和BL之间的协调以确定LUT脊髓网络的结构和功能差异 在雄性和雌性之间。在脊髓切片制备中，我们将使用转基因小鼠表达通道 视紫红质(ChR2)在抑制性或兴奋性神经元研究EUS运动神经元对光刺激的反应 嵌入特定脊髓通路的LUT相关脊髓中间神经元的活动，并将识别和 描述负责EUS松弛的抑制回路。我们将定义L3/L4的角色 LSCC在EUS运动神经元活动和EUS松弛中的作用及其与L6/S1运动神经元的相互作用方式 游泳池。我们将评估L6/S1中假想的递归抑制回路对产生 EUS的爆裂和松弛以及膀胱-括约肌的协调。 这项研究计划的长远目标是加深我们对 脊髓损伤后DSD和排尿问题的病理生理机制及开发新的有效途径 治疗脊髓疾患中DSD的治疗干预。考虑与性别相关的 LUT神经控制的差异男性和女性治疗DSD的不同方法可能是 推荐的。

Project summary Detrusor-sphincter-dyssynergia (DSD) is a major urological problem inducing inefficient voiding, increased amount of post-void residual urine and high intravesical pressure after spinal cord injury (SCI). Until recently the majority of studies on spinal mechanisms of coordination between external urethral sphincter (EUS) and the bladder (BL) were conducted in female rats, although in clinical practice DSD develops more often in males. Furthermore, sexual dimorphism in anatomy and function of the lower urinary tract (LUT) suggests differences in the spinal neural circuits of male and female. With development of genetic modifications and optogenetic techniques the mouse model of LUT dysfunction is becoming more useful than the rat. Therefore, in the proposed project “Intraspinal circuits supporting synergy between the bladder and urethral sphincter in mice” we will use transgenic mice of both sexes for electrophysiological, optogenetic, immunohistochemical, pharmacological and anatomical studies of spinal cord circuits involved in interaction between the bladder (BL) and the external urethral sphincter (EUS) in spinal intact animals and after spinal cord injury. We will test several hypotheses in in vivo and in vitro experiments. In urethane anesthetized animals of both sexes, we will determine functional differences in spinal regulation of micturition and in control and SCI mice. Male and female animals will be also used to determine hypothesized sexual dimorphism in LUT-related spinal circuits and their plasticity after chronic SCI. Using electrical stimulation of the Lumbar Spinal Coordinating Center (LSCC) which we have recently discovered in L3/L4 spinal segments, we will test whether an external command can initiate voiding. Using trans-synaptic viral labeling, we will trace neuronal populations involved in coordination between EUS and BL to determine structural and functional differences in LUT spinal networks between males and females. In spinal cord slice preparations, we will use transgenic mice expressing channel rhodopsin (ChR2) in inhibitory or excitatory neurons to study reactions of EUS motoneurons to light-evoked activity of LUT-related spinal interneurons embedded in specific spinal pathways, and will identify and characterize the inhibitory circuit which is responsible for EUS relaxation. We will define the role of the L3/L4 LSCC in activity of EUS motoneurons and EUS relaxation and its mode of interaction with L6/S1 motor neuronal pool. We will evaluate the contribution of a hypothesized recurrent inhibitory circuit in L6/S1 to the generation of EUS bursting and relaxation as well as to bladder-sphincter coordination. The long-term objectives of the research project are to increase our understanding of the pathophysiological mechanisms inducing DSD and voiding problems after SCI and to develop new and effective therapeutic interventions for the treatment of DSD in spinal cord disorders. Considering gender related differences in neural control of the LUT different approaches to DSD treatment in males and females may be recommended.