Janet Keast (PI)
University of Melbourne
This foundational project will produce mesoscopic and microscopic functional anatomical maps of the sensory and autonomic (motor) neurons that regulate the lower urinary tract (LUT). Neural dysfunction is a major contributor to diverse, largely intractable urological problems, including overactive or underactive bladder, incontinence due to ageing or pelvic surgery, and painful bladder syndrome/interstitial cystitis. We will fill knowledge gaps and overcome diverse technical roadblocks to develop maps that provide a critical foundation for modeling different LUT behaviors, understanding neuromodulatory mechanisms, and determining off-target effects of neuromodulation. We will conduct this study in adult rats, the species where the peripheral and spinal circuitry of the LUT is defined in the most detail and, compared with mice, their larger size facilitates development of devices. Together, this will facilitate development of new methods for normalizing over- or underactivity in these circuits.
Keast, JR; Smith-Anttila, CJ; Osborne, PB. Front Cell Dev Biol. vol. 3, 53. September 2015.
The development of organs occurs in parallel with the formation of their nerve supply. The innervation of pelvic organs (lower urinary tract, hindgut, and sexual organs) is complex and we know remarkably little about the mechanisms that form these neural pathways. The goal of this short review is to use the urinary bladder as an example to stimulate interest in this question. The bladder requires a healthy mature nervous system to store urine and release it at behaviorally appropriate times. Understanding the mechanisms underlying the construction of these neural circuits is not only relevant to defining the basis of developmental problems but may also suggest strategies to restore connectivity and function following injury or disease in adults. The bladder nerve supply comprises multiple classes of sensory, and parasympathetic or sympathetic autonomic effector (motor) neurons. First, we define the developmental endpoint by describing this circuitry in adult rodents. Next we discuss the innervation of the developing bladder, identifying challenges posed by this area of research. Last we provide examples of genetically modified mice with bladder dysfunction and suggest potential neural contributors to this state.
Georgas, KM; Armstrong, J; Keast, JR; Larkins, CE; McHugh, KM; Southard-Smith, EM; Cohn, MJ; Batourina, E; Dan, H; Schneider, K; Buehler, DP; Wiese, CB; Brennan, J; Davies, JA; Harding, SD; Baldock, RA; Little, MH; Vezina, CM; Mendelsohn, C. Development. vol. 142(10), 1893–908. May 2015.
Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation.