%0 Journal Article
%T Localization of peroxisome proliferator-activated receptor alpha (PPAR¦Á) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) in cells expressing the Ca2+-binding proteins calbindin, calretinin, and parvalbumin in the adult rat hippocampus
%A Patricia Rivera
%A Sergio Arrabal
%A Antonio Vargas
%A Eduardo Blanco
%A Antonia Serrano
%A Francisco J. Pav¨®n
%A Fernando Rodr¨ªguez de Fonseca
%A Juan Su¨¢rez
%J Frontiers in Neuroanatomy
%D 2014
%I Frontiers Media
%R 10.3389/fnana.2014.00012
%X The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPAR¦Á receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca2+ fluxes. Thus, the identification of a specific population of NAPE-PLD/PPAR¦Á-containing neurons that express selective Ca2+-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPAR¦Á system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPAR¦Á and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPAR¦Á expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPAR¦Á was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPAR¦Á+/calbindin+ cells were closely surrounded by NAPE-PLD+ fiber varicosities. No pyramidal PPAR¦Á+/calbindin+ cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPAR¦Á in the principal layers of the DG and CA1/3. A small number of cells containing PPAR¦Á and calretinin was found along the hippocampus. Scattered NAPE-PLD+/calretinin+ cells were specifically detected in CA3. NAPE-PLD+ puncta surrounded the calretinin+ cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPAR¦Á-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPAR¦Á-signaling system in the regulation of hippocampal functions.
%K PPAR alpha
%K NAPE-PLD
%K calcium-binding protein
%K hippocampus
%K rat
%K immunohistochemistry
%K confocal microscopy
%U http://www.frontiersin.org/Journal/10.3389/fnana.2014.00012/abstract