Characterization of uterine-related central nervous system pathways

The central nervous system circuitry involved in innervation of the uterine cervix during parturition has not been studied. Therefore the goal of this dissertation was to characterize neurons within the rat lumbosacral spinal cord and hypothalamic paraventricular nucleus that may be important components of the circuitry for uterine cervical innervation and may be activated during parturition. Four Specific Aims were addressed.; Aim 1 was designed to determine the presence, distribution, and origin of oxytocin-containing nerves in the spinal cord.; Aim 2 was designed to determine the presence, distribution, and origin of corticotropin releasing factor-containing nerves in the spinal cord.; Aim 3 was designed to determine if neurons in the spinal cord and hypothalamic paraventricular nucleus are activated by a pup passing through the uterine cervix at parturition, and to study some neurochemical characteristics and axonal projections of these neurons.; Aim 4 was designed to determine if receptors for oxytocin and corticotropin releasing factor are present on neurons in the lumbosacral spinal cord.; Techniques used for investigating these aims include multiple labeling immunohistochemistry, retrograde axonal tracers, spinal cord transections and activity-dependent activation of immediate early genes. This study determined that nerve fibers containing oxytocin and corticotropin releasing factor are present within the lumbosacral spinal cord in areas involved in sensory and autonomic processing. The cell bodies of origin for some of these fibers are from the hypothalamic paraventricular nucleus. Spinal cord neurons activated at parturition are present in areas associated with sensory and autonomic processing. Some of these neurons contain estrogen receptor a and some project axons to the hypothalamus. Hypothalamic paraventricular neurons are also activated at parturition and some of these neurons project axons to the lumbosacral spinal cord and contain oxytocin or corticotropin releasing factor. Moreover, receptors for oxytocin and corticotropin releasing factor are present in spinal cord areas involved in sensory and autonomic processing.; These data help fill some informational gaps concerning circuitry in the central nervous system that help coordinate and transmit information about events at parturition and promote our understanding of the neural involvements in reproductive organs involved in pregnancy and parturition.