Central nervous system neurons labeled following the injection of pseudorabies virus into the rat prostate gland

BACKGROUND: The human prostate gland plays an important role in male fertility and is involved in different functional pathologies of the male lower urinary tract (LUT). The role of the prostate in these medical disorders is mainly unknown. Traditional surgical therapeutic attempts often fail to help these patients. For years, the clinical sciences have been stagnating due to a lack of basic science knowledge. Investigations into neuroanatomy and neurophysiology are urgently needed. Therefore, the neuroanatomy of the prostate gland in an experimental setup was explored. Recent progress in neuroscience methodology allows a transneuronal tracing by using a self-amplifying virus tracer, pseudorabies virus (PRV). METHODS: Sixty-two individual adult male Sprague-Dawley rats were used for retrograde transneuronal mapping of the spinal cord and brain stem after PRV-injection and control experiments. A PRV-tracer (5 microl, 1 x 10(8) pfu/ml) was injected into the prostate gland. After a survival time of 72, 96, or 120 hr, the animals were sacrificed. Brain and spinal cord were harvested via a dorsal laminectomy. After cutting on a freezing microtome, the tissue was immunostained for PRV. RESULTS: PRV-positive cells were found within the sacral (S1-S2) and the thoracolumbar (T13-L2) spinal cord. At the supraspinal level, positive cells were found within the following regions: nucleus raphe, lateral reticular formation, nucleus gigantocellularis, A5 noradrenergic cell region, locus coeruleus, pontine micturition center, hypothalamus, medial preoptic region, and periaquaductal gray. CONCLUSIONS: This is the first investigation on the central innervation of the prostate gland showing a broad central representation of neurons involved in the control of the prostate gland. It is obvious, comparing data from the literature, that there is a broad overlap in the innervation of pelvic visceral organs (bladder, rectum, and urethra). The appreciation of these neuroanatomical circumstances allows a growing understanding of common urological pathologies within the pelvis (pelvic pain, lower urinary tract, and bowel dysfunction).