Estrogen receptor-alpha immunoreactivity in parasympathetic preganglionic neurons innervating the bladder in the...

Estrogen affects autonomic functions such as micturition. The sacral cord is important in the control of micturition and contains numerous estrogen receptor-alpha immnoreactive (ER-alpha IR) neurons. Therefore, the present double labeling study examines whether sacral parasympathetic preganglionic neurons innervating the bladder are immunoreactive for ER-alpha. In the sacral cord of seven female ovariectomized cats, the distribution of ER-alpha IR neurons was studied using the H222 and 1D5 antibodies. Choleratoxin subunit b (CTb) was injected into the bladder wall to visualize its preganglionic neurons. ER-alpha IR was present in the nuclei of cells in laminae I, II, V, VII, and X, and in nuclei and cytoplasm of neurons in the sacral parasympathetic nucleus. The vast majority of CTb labeled neurons contained ER-alpha IR nuclei, indicating that preganglionic neurons innervating the bladder express ER-alpha. The results suggest that estrogen modulates micturition in the cat via ER-alpha in bladder preganglionic neurons.