Developmental Plasticity of Micturition Reflexes

描述（由申请方提供）：在产前和产后发育期间，尿液储存和定期排泄的相关机制表现出显著变化。在年轻的胎儿中，在神经系统成熟之前，尿液可能通过非神经机制从膀胱排出。在发育的后期，排尿由脊髓反射途径调节。随着中枢神经系统在出生后时期继续成熟，反射性排尿受到涉及高级大脑中心的自愿控制。在成年人中，神经系统的损伤或疾病可能导致原始功能的重新出现，这些功能在发育早期很突出，但在神经成熟期间受到抑制。因此，排尿反射通路的发育研究可能提供关键的洞察力的机制，神经源性疾病的膀胱功能在成年人。这项研究计划将集中在脊髓反射排尿机制的变化，在出生后早期排尿功能的成熟。 Aim I）。目的：观察膀胱中间神经元和副交感节前神经元在腰骶髓的分布。将使用伪狂犬病病毒（Bartha株）跨神经元示踪和常规逆行染料作图技术（荧光金）的组合。将使用基于设计的体视学技术，在脊髓延髓排尿反射出现之前（P1、P7、P14）和之后（P21、P28、P36），在出生后大鼠中评估各种脊髓元件之间连接性的变化。 目标2）。研究出生后大鼠脊髓延髓排尿反射出现前后下尿路传入（A-和/或C-纤维）信息中枢处理的变化。将利用轴突示踪技术和Fos蛋白表达的组合。这些实验将决定A- 和/或C纤维膀胱传入在出生后早期发育期间是活跃的，以及传入信息如何由脊髓不同区域中的不同神经元处理。 目标3）。目的：观察大鼠生后脊髓延髓排尿反射出现前后，会阴传入神经纤维和球脊髓投射与腰骶髓中间神经元和（或）节前神经元紧密贴壁的终止方式、面积和形态。这些研究将确定会阴传入投射（Dil或WGA-HRP标记）和/或球脊髓（CRF-IR）投射和静脉曲张在腰骶脊髓中是否突出，以及哪些神经元群与传入或球脊髓传出投射密切并列。将结合腰骶脊髓中CRF的解剖学研究和免疫测定。

DESCRIPTION (provided by applicant): The mechanisms involved in the storage and periodic elimination of urine exhibit marked changes during prenatal and postnatal development. In the young fetus, prior to maturation of the nervous system, urine is presumably eliminated from the urinary bladder by non-neural mechanisms. At later stages of development, micturition is regulated by spinal reflex pathways. As the central nervous system continues to mature during the postnatal period, reflex voiding is brought under voluntary control involving higher brain centers. In adults, injuries or diseases of the nervous system can lead to the reemergence of primitive functions that were prominent early in development but then were suppressed during neural maturation. Therefore, developmental studies of micturition reflex pathways are likely to provide key insights into the mechanisms underlying neurogenic disorders of urinary bladder function in adults. This research proposal will focus on alterations in spinal reflex voiding mechanisms that underlie the maturation of voiding function during the early postnatal period. Aim I). To determine the organization of urinary bladder interneurons and parasympathetic preganglionic neurons in the lumbosacral spinal cord. A combination of transneuronal tracing with pseudorabies virus (Bartha strain) and conventional retrograde dye mapping techniques (Fluorogold) will be utilized. Changes in connectivity between the various spinal elements will be assessed in postnatal rats prior to (P1, P7, P14) and following (P21, P28, P36) the emergence of the spinobulbospinal micturition reflex using design-based stereological techniques. Aim 2). To examine changes in central processing of afferent (A-s and/or C-fiber) information from the lower urinary tract of postnatal rats prior to and following the emergence of the spinobulbospinal micturition reflex. A combination of axonal tracing techniques and Fos protein expression will be utilized. These experiments will determine if A- and/or C-fiber bladder afferents are active during early postnatal development and how afferent information is processed by different neurons in different regions of the spinal cord. Aim 3). To examine the termination pattern, area occupied and morphology of perineal afferent nerve fibers and bulbospinal projections in close apposition to interneurons and/or preganglionic neurons in the lumbosacral spinal cord in postnatal rats prior to and following the emergence of the spinobulbosninal micturition reflex. These studies will determine if perineal afferent projections (Dil or WGA-HRP-labeled) and/or bulbospinal (CRF-IR) projections and varicosities are prominent in the lumbosacral spinal cord and which neuronal populations are in close apposition to afferent or bulbospinal efferent projections. Anatomical studies will be combined with immunoassay for CRF in the lumbosacral spinal cord.