Rich Ependymal Investment of Luliberin (LHRH) Fibers Revealed Immunocytochemically in an Image like that from Golgi Stain

Immunospecific staining in 100-$\mu $m-thick Vibratome section by the unlabeled antibody method resembles Golgi staining and reveals an abundance of luliberin- (luteinizing hormone releasing hormone, LHRH) positive cells and fibers in close contact with the surface of the third ventricle. The polarity of LHRH cells can be seen and processes can be traced for several millimeters. In the medial preoptic and suprachiasmatic areas bipolar LHRH neurons send short stout processes to the ventricular surface and long processes toward the organum vasculosum laminae terminalis. These cells resemble the receptor cells contacting the cerebrospinal fluid that have been described by Vigh and Vigh-Teichmann [Vigh, B. & Vigh-Teichmann, I. (1973) Int. Rev. Cytol. 35, 189-251]. In the septal region some bipolar neurons send both of their processes towards the ventricular surface. LHRH neurons in the nucleus of the anterior commissure and the bed nucleus of the stria terminalis project over the anterior commissure to form a dense plexus of fibers in the subfornical organ. The proximity of LHRH perikarya and fibers to the ventricular surface supports the hypothesis [Knigge, K. M., Joseph, S. A., Scott, D. E. & Jacobs, J. J. (1971) in The Neuroendocrinology of Human Reproduction, eds. Mack, H. C. & Sherman, A. J., (Thomas, Springfield, IL), pp. 6-22.] that the cerebrospinal fluid functions in neuroendocrine control mechanisms.