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Association of neuropeptide Y Y1 receptors with glutamate‐positive and NPY‐positive neurons in rat hippocampal cultures
Author(s) -
StPierre JacquesAndré,
Nouel Dominique,
Dumont Yvan,
Beaudet Alain,
Quirion Rémi
Publication year - 2000
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1046/j.1460-9568.2000.00024.x
Subject(s) - neuropeptide y receptor , receptor , glutamate receptor , hippocampal formation , medicine , endocrinology , biology , hippocampus , neuron , immunostaining , neuropeptide , enolase , biochemistry , neuroscience , immunohistochemistry , immunology
The hippocampus is particularly enriched with neuropeptide tyrosine (NPY) and NPY receptors including the Y 1 , Y 2 and Y 5 subtypes. We have previously reported on the enrichment of cultured rat hippocampal neurons in specific [ 125 I][Leu 31 ,Pro 34 ]PYY/BIBP3226‐sensitive (Y 1 ) binding sites and Y 1 receptor mRNAs [St‐Pierre et al . (1998) Br. J. Pharmacol., 123, p183]. We have now identified which cell types express the Y 1 receptor. The majority of Y 1 receptors, visualized using either the radiolabeled probe [ 125 I][Leu 31 ,Pro 34 ]PYY or two antibodies directed against distinct domains of the Y 1 receptor, was expressed in neurons as revealed by neuron‐specific enolase (NSE) immunostaining. One antibody was directed against the second extracelllular loop of the Y1 receptor (amino acids 185–203) whereas the second was directed against the intracellular C‐terminal loop (amino acids 355–382). The labelling was evident over both perikarya and processes. Neurons labelled by the various Y 1 receptor probes were mostly glutamate‐positive as revealed by double immunostaining. Most interestingly, a number of NPY‐positive cultured hippocampal neurons were also enriched with the Y 1 receptor, suggesting that this subtype may act as an autoreceptor to regulate NPY release in the hippocampus. These results thus provide an anatomical basis for the modulation of glutamate and NPY release by the Y 1 receptor in the hippocampus.