RGD Reference Report - Subcellular localization of metabotropic GABA(B) receptor subunits GABA(B1a/b) and GABA(B2) in the rat hippocampus. - Rat Genome Database

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Subcellular localization of metabotropic GABA(B) receptor subunits GABA(B1a/b) and GABA(B2) in the rat hippocampus.

Authors: Kulik, Akos  Vida, Imre  Luján, Rafael  Haas, Carola A  López-Bendito, Guillermina  Shigemoto, Ryuichi  Frotscher, Michael 
Citation: Kulik A, etal., J Neurosci. 2003 Dec 3;23(35):11026-35.
RGD ID: 13702400
Pubmed: PMID:14657159   (View Abstract at PubMed)
PMCID: PMC6741037   (View Article at PubMed Central)

Metabotropic GABA(B) receptors mediate slow inhibitory effects presynaptically and postsynaptically. Using preembedding immunohistochemical methods combined with quantitative analysis of GABA(B) receptor subunit immunoreactivity, this study provides a detailed description of the cellular and subcellular localization of GABA(B1a/b) and GABA(B2) in the rat hippocampus. At the light microscopic level, an overlapping distribution of GABA(B1a/b) and GABA(B2) was revealed in the dendritic layers of the hippocampus. In addition, expression of the GABA(B1a/b) subunit was found in somata of CA1 pyramidal cells and of a subset of GABAergic interneurons. At the electron microscopic level, immunoreactivity for both subunits was observed on presynaptic and, more abundantly, on postsynaptic elements. Presynaptically, subunits were mainly detected in the extrasynaptic membrane and occasionally over the presynaptic membrane specialization of putative glutamatergic and, to a lesser extent, GABAergic axon terminals. Postsynaptically, the majority of GABA(B) receptor subunits were localized to the extrasynaptic plasma membrane of spines and dendritic shafts of principal cells and shafts of interneuron dendrites. Quantitative analysis revealed enrichment of GABA(B1a/b) around putative glutamatergic synapses on spines and an even distribution on dendritic shafts of pyramidal cells contacted by GABAergic boutons. The association of GABA(B) receptors with glutamatergic synapses at both presynaptic and postsynaptic sides indicates their intimate involvement in the modulation of glutamatergic neurotransmission. The dominant extrasynaptic localization of GABA(B) receptor subunits suggests that their activation is dependent on spillover of GABA requiring simultaneous activity of populations of GABAergic cells as it occurs during population oscillations or epileptic seizures.

Gene Ontology Annotations    Click to see Annotation Detail View

Cellular Component
TermQualifierEvidenceWithReferenceNotesSourceOriginal Reference(s)
GABA-ergic synapse is_active_inIDA 13702400; 13702400PMID:14657159SynGO 
glutamatergic synapse is_active_inIDA 13702400; 13702400PMID:14657159SynGO 
postsynaptic membrane is_active_inIDA 13702400; 13702400PMID:14657159SynGO 
presynaptic membrane is_active_inIDA 13702400; 13702400PMID:14657159SynGO 

Objects Annotated

Genes (Rattus norvegicus)
Gabbr1  (gamma-aminobutyric acid type B receptor subunit 1)
Gabbr2  (gamma-aminobutyric acid type B receptor subunit 2)


Additional Information