Tracing studies in rat provide sensitive gene expression data for neurons innervating the bladder and urethra

Abstract

The aim of the study was to explore novel tissue based techniques to generate gene expression profiles of both afferent (sensory) and efferent (motor) neurons that specifically innervate the rat bladder and urethra.Retrograde neuronal tracing studies in combination with laser capture microdissection (LCM) and microarray analysis were used to generate gene expression profiles of both afferent and efferent neurons that specifically innervate the rat bladder and urethra. A complete rat study (n=12) was performed in which fluorescently labelled cholera toxin B was injected into the bladder and urethra. Traced neurons were isolated by LCM, RNA was extracted, amplified and analysed by microarray.Extensive analysis of all the data derived from this study give very sensitive and powerful gene expression data from only 50–100 microdissected neurons. Expression of sensory neuron specific markers could be confirmed in dorsal root ganglion neurons whereas expression of genes involved in motor function of the lower urinary tract could be confirmed in efferent neurons e.g. Onuf's Nucleus.The resulting gene expression profile will increase our understanding of signalling pathways involved in the control of the lower urinary tract. Data derived from this study will not only be relevant for safety and efficacy but will also enable us to identify targets for the treatment of urinary frequency and urge incontinence (UFUI).