title: Gamma-aminobutyric acid and related molecules in the sea fan Eunicella cavolini (Cnidaria: Octocorallia): a biochemical and immunohistochemical approach.
abstract: The aim of this study has been the biochemical demonstration of the presence of gamma-aminobutyric acid (GABA) in the Mediterranean sea fan Eunicella cavolini by means of high-performance liquid chromatography, and the description of the distribution pattern of GABA and its related molecules, glutamic acid decarboxylase (GAD), vesicular GABA transporter (VGAT) and one of the GABA receptors (GABA(B) R) by immunohistochemical methods. The interrelationships of GABA, GAD and GABA receptor immunoreactivity have been established by using double-immunohistochemical methods and confocal microscopy. The immunodetection of monoclonal and/or polyclonal antibodies has revealed GABA immunoreactivity throughout the polyp tissue, both in neuronal and non-neuronal elements. GAD immunoreactivity has been mostly localized in the neuronal compartment, contacting epithelial and muscular elements. GABA(B) R immunoreactivity appears particularly intense in the nematocytes and in the oocyte envelope; its presence in GAD-immunoreactive neurons in the tentacles suggests an autocrine type of regulation. Western blot analysis has confirmed that a GABA(B) R, with a molecular weight of 142 kDa, similar to that of rat brain, is present in E. cavolini polyp tissue. The identification of the sites of the synthesis, vesicular transport, storage and reception of GABA strongly suggests the presence of an almost complete set of GABA-related molecules for the functioning of the GABAergic system in this simple nervous system. The distribution of these different immunoreactivities has allowed us to hypothesize GABA involvement in nematocyst discharge, in body wall and enteric muscular contraction, in neuronal integration and in male gametocyte differentiation.
authors: Dipartimento Biologia, Università di Genova, Genoa, Italy. laura.girosi@unige.it
authors: Laura
authors: L
authors: Girosi
authors: Sara
authors: S
authors: Ferrando
authors: Francesco
authors: F
authors: Beltrame
authors: Gaetano
authors: G
authors: Ciarcia
authors: Alberto
authors: A
authors: Diaspro
authors: Marco
authors: M
authors: Fato
authors: Mirko
authors: M
authors: Magnone
authors: Luca
authors: L
authors: Raiteri
authors: Paola
authors: P
authors: Ramoino
authors: Grazia
authors: G
authors: Tagliafierro
mesh_terms: D000818:Animals; D003063:Cnidaria / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D005260:Female; D050485:GABA Plasma Membrane Transport Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005968:Glutamate Decarboxylase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity / Q000502:physiology; D051381:Rats; D018080:Receptors, GABA-B / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D050485:GABA Plasma Membrane Transport Proteins; D018080:Receptors, GABA-B; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase