This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wittmann, G. Articles by Fekete, C. Search for Related Content PubMed PubMed Citation Articles by Wittmann, G. Articles by Fekete, C.

Origin of Cocaine- and Amphetamine-Regulated Transcript-Containing Axons Innervating Hypophysiotropic Corticotropin-Releasing Hormone-Synthesizing Neurons in the Rat

Department of Endocrine Neurobiology (G.W., Z.L., C.F.), Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary; and Tupper Research Institute and Department of Medicine (R.M.L., C.F.), Division of Endocrinology, Diabetes, Metabolism, and Molecular Medicine, Tufts-New England Medical Center, and Department of Neuroscience (R.M.L.), Tufts University School of Medicine, Boston, Massachusetts 02111

Address all correspondence and requests for reprints to: Csaba Fekete M.D., Ph.D., Department of Endocrine Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest 1083, Hungary. E-mail: feketecs{at}koki.hu.

Cocaine- and amphetamine-regulated transcript (CART) has stimulatory effects on the hypothalamic-pituitary-adrenal axis through direct effects on hypophysiotropic CRH neurons. Recently CART-containing axons have been demonstrated to densely innervate the hypophysiotropic CRH neurons. Based on the sources of the CART-immunoreactive (IR) innervation of the paraventricular nucleus, the putative origins of these CART-containing fibers include neurons of the hypothalamic arcuate nucleus that coexpress MSH and medullary adrenaline-producing neurons. To determine whether these cell groups contribute to the CART innervation of the hypophysiotropic CRH neurons, we performed a quadruple-labeling immunofluorescent study using antisera against CRH, CART, MSH, and phenylethanolamine-N-methyl-transferase (PNMT), the latter as a marker for adrenaline. Consistent with previous observations, PNMT- and CART-IR axons densely innervated all CRH neurons, whereas the MSH-IR innervation was sparse. Although approximately 60% of CART-IR varicosities in juxtaposition to CRH neurons cocontained PNMT, only approximately 18% of them were immunopositive for MSH. All MSH-IR boutons and approximately 90% of PNMT-containing varicosities on the surface of CRH neurons were also labeled for CART. The remaining 22% of CART axon varicosities in contact with CRH neurons contained neither MSH nor PNMT. These results indicate that medullary adrenergic/CART neurons are the major source for the CART innervation of CRH neurons in the paraventricular nucleus; however, to a lesser extent the arcuate nucleus also contributes to the CART-IR innervation of these neurons. The observation that nearly 20% of the CART-IR afferents contain neither MSH nor PNMT, however, suggests that additional sources also contribute to the CART-IR input of hypophysiotropic CRH neurons.

This article has been cited by other articles:

				J. Menyhert, G. Wittmann, R. M. Lechan, E. Keller, Z. Liposits, and C. Fekete Cocaine- and Amphetamine-Regulated Transcript (CART) Is Colocalized with the Orexigenic Neuropeptide Y and Agouti-Related Protein and Absent from the Anorexigenic {alpha}-Melanocyte-Stimulating Hormone Neurons in the Infundibular Nucleus of the Human Hypothalamus Endocrinology, September 1, 2007; 148(9): 4276 - 4281. [Abstract] [Full Text] [PDF]

				S. M. Smith, J. M. Vaughan, C. J. Donaldson, R. E. Fernandez, C. Li, A. Chen, and W. W. Vale Cocaine- and Amphetamine-Regulated Transcript Is Localized in Pituitary Lactotropes and Is Regulated during Lactation Endocrinology, March 1, 2006; 147(3): 1213 - 1223. [Abstract] [Full Text] [PDF]