Organization of Ovine Corticotropin-Releasing Factor Immunoreactive Cells and Fibers in the Rat Brain: An Immunohistochemical Study

The distribution of corticotropin-releasing factor (CRF)-immunoreactive cells and fibers has been examined in the brains of normal adult rats, and in the brains of animals that had been pretreated with intraventricular injections of colchicine, or had been adrenalectomized 3-60 days before perfusion. The results suggest that CRF immunoreactivity is localized in at least three functionally distinct systems. First, most of the CRF-stained fibers in the neurohemal zone of the median eminence, which presumably modulate the release of ACTH and beta-endorphin from the pituitary, appear to arise in the paraventricular nucleus of the hypothalamus (PVH). About 2,000 CRF-stained cells are distributed throughout all…