Central administration of cocaine- and amphetamine-regulated transcript increases phosphorylation of cAMP response element binding protein in corticotropin-releasing hormone-producing neurons but not in prothyrotropin-releasing hormone-producing neurons in the hypothalamic paraventricular nucleus

• Published in: Brain research 2004-03, Vol.999 (2), p.181-192
• Main Authors: Sarkar, Sumit, Wittmann, Gábor, Fekete, Csaba, Lechan, Ronald M.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cell Count; Cocaine- and amphetamine-regulated transcript; Corticotropin-releasing hormone; Corticotropin-Releasing Hormone - metabolism; Corticotropin-Releasing Hormone - secretion; Cyclic adenosine 5′-monophosphate response element binding protein; Cyclic AMP Response Element-Binding Protein - drug effects; Cyclic AMP Response Element-Binding Protein - metabolism; Dendrites - metabolism; Dendrites - ultrastructure; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - physiology; Hormones and neuropeptides. Regulation; Hypothalamo-Hypophyseal System - drug effects; Hypothalamo-Hypophyseal System - metabolism; Hypothalamo-Hypophyseal System - secretion; Hypothalamus. Hypophysis. Epiphysis. Urophysis; Immunohistochemistry; Male; Microscopy, Electron; Nerve Tissue Proteins - metabolism; Nerve Tissue Proteins - pharmacology; Neurons - drug effects; Neurons - metabolism; Neurons - ultrastructure; Paraventricular Hypothalamic Nucleus - drug effects; Paraventricular Hypothalamic Nucleus - metabolism; Paraventricular Hypothalamic Nucleus - secretion; Phosphorylation - drug effects; Presynaptic Terminals - metabolism; Presynaptic Terminals - ultrastructure; Protein Precursors - metabolism; Protein Precursors - secretion; Pyrrolidonecarboxylic Acid - analogs & derivatives; Rats; Rats, Sprague-Dawley; Thyrotropin-releasing hormone; Thyrotropin-Releasing Hormone - metabolism; Thyrotropin-Releasing Hormone - secretion; Up-Regulation - drug effects; Up-Regulation - physiology; Vertebrates: endocrinology
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2003.11.062

Cocaine- and amphetamine-regulated transcript (CART) has an important action on hypophysiotropic thyrotropin-releasing hormone (TRH) and corticotropin-releasing hormone (CRH) neurons to regulate the hypothalamic–pituitary–thyroid and adrenal axis, respectively. To elucidate the mechanisms by which CART mediates its effect on TRH and CRH neurons, we determined whether the exogenous administration of CART into the cerebrospinal fluid (CSF) phosphorylates the transcription factor, cyclic adenosine 5′-monophosphate response element binding protein (CREB), in the nucleus of TRH and CRH neurons. CART dramatically increased the percentage of phosphoCREB (PCREB) immunolabeled cell nuclei in the hypothalamic paraventricular nucleus (PVN) in fasted as well as fed rats at 10-min postinjection, particularly in the medial parvocellular subdivision of the PVN. Double immunolabelling with CRH antiserum revealed that CART increased the number of CRH neurons containing PCREB from 10.5±1.2 % to 87±1.2% ( P