IHEM   20887
INSTITUTO DE HISTOLOGIA Y EMBRIOLOGIA DE MENDOZA DR. MARIO H. BURGOS
Unidad Ejecutora - UE
artículos
Título:
GABAergic signaling in the rat pineal gland
Autor/es:
S.G. BENITEZ; M. KRUSE; S-R. JUNG; E.M. MUÑOZ (ÚLTIMA AUTORÍA COMPARTIDA); J-B. SEO; B. HILLE ; H. YU; L.E. FARIAS ALTAMIRANO; D-S. KOH
Revista:
JOURNAL OF PINEAL RESEARCH
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2016 vol. 61 p. 69 - 81
ISSN:
0742-3098
Resumen:
Primera autoría compartida: H. Yu; S.G. Benitez. Ultima autoría compartida: E.M. Muñoz; B. Hille. 25-Mar-2016Dear Prof. Hille:It is a pleasure to accept your manuscript entitled "GABAergic signaling in the rat pineal gland" in its current form for publication in the Journal of Pineal Research. The comments of the reviewer(s) who reviewed your manuscript are included at the foot of this letter.Copyright Transfer AgreementYour article cannot be published until the publisher has received the appropriate signed license agreement. Within the next few days the corresponding author will receive an email from Wiley?s Author Services system which will ask them to log in and will present them with the appropriate license for completion.Thank you for your fine contribution. On behalf of the Editors of the Journal of Pineal Research, we look forward to your continued contributions to the Journal.Sincerely,Dr. Russel ReiterEditor-in-Chief, Journal of Pineal Researchreiter@uthscsa.edu. Abstract: Pinealocytes secrete melatonin at night in response to norepinephrine released from sympathetic nerve terminals in the pineal gland. The gland also contains many other neurotransmitters whose cellular disposition, activity, and relevance to pineal function are not understood. Here we clarify sources and demonstrate cellular actions of the neurotransmitter γ-aminobutyric acid (GABA) using Western blotting and immunohistochemistry of the gland and electrical recording from pinealocytes. GABAergic cells and nerve fibers, defined as containing GABA and the synthetic enzyme GAD67, were identified. The cells represent a subset of interstitial cells while the nerve fibers were distinct from the sympathetic innervation. The GABAA receptor subunit α1 was visualized in close proximity of both GABAergic and sympathetic nerve fibers as well as fine extensions among pinealocytes and blood vessels. The GABAB1 receptor subunit was localized in the interstitial compartment but not in pinealocytes. Electrophysiology of isolated pinealocytes revealed that GABA and muscimol elicit strong inward chloride currents sensitive to bicuculline and picrotoxin, clear evidence for functional GABAA receptors on the surface membrane. Applications of elevated potassium solution or the neurotransmitter acetylcholine depolarized the pinealocyte membrane potential enough to open voltage-gated Ca2+ channels leading to intracellular calcium elevations. GABA repolarized the membrane and shut off such calcium rises. In 48-72-h cultured intact glands, GABA application neither triggered melatonin secretion by itself nor affected norepinephrine-induced secretion. Thus strong elements of GABA signaling are present in pineal glands that make large electrical responses in pinealocytes, but physiological roles need to be found.