Prostate- and bladder-labeled neurons in the brain Neurons in selected brain nuclei, arranged in caudal to rostral order labeled by virus from the bladder and virus from the prostate. A: Raphe and gigantocellular reticular nuclei. Double-labeled neurons are common. B: The A5 adrenergic nucleus. Note that there are numerous double-labeled neurons. C: The locus coeruleus. Several neurons are double-labeled. D: Barrington's nucleus (the pontine micturition center). Bladder virus labels the overwhelming number of neurons. Only a few neurons contain prostate virus. E: The paraventricular nucleus. Approximately equal numbers of bladder and prostate neurons. Some are double-labeled. F: The medial preoptic nucleus. Only bladder neurons are found.