Synaptic localization of the glutamate receptor subunit GluR2 in the rat nucleus tractus solitarii.
The GluR2 subunit controls several key features of the alpha amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-type glutamate receptor including calcium permeability, rectification and gating. In the present study, electrophysiological recordings and immunocytochemistry were used to document the synaptic localization of GluR2 in the rat nucleus tractus solitarii (NTS). Synaptic responses recorded in NTS neurons exhibited linear current-voltage relationships suggestive of GluR2-containing AMPA receptor responses. Furthermore, after antigen retrieval GluR2 immunolabelling in the NTS mainly consisted of small puncta. Double-labelling experiments showed that these GluR2 puncta were apposed to glutamatergic synaptic terminals identified by type II vesicular glutamate transporter immunoreactivity. These results indicate that NTS glutamatergic synapses are endowed with AMPA receptors which contain the GluR2 subunit and are therefore likely to be both calcium-impermeable and slowly desensitizing.
Lachamp
Philippe
P
ITIS, UMR 6150, Centre National de la Recherche Scientifique et Université de la Méditerranée, IFR Jean Roche, Faculté de Médecine Nord, Bd Pierre Dramard, F13916 Marseille cedex 20, France.
Balland
Bénédicte
B
Tell
Fabien
F
Crest
Marcel
M
Kessler
Jean-Pierre
JP
D000818:Animals; D000831:Animals, Newborn; D002352:Carrier Proteins / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000528:radiation effects; D007150:Immunohistochemistry / Q000379:methods; D066298:In Vitro Techniques; D026901:Membrane Transport Proteins; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D018408:Patch-Clamp Techniques / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism*; D017552:Solitary Nucleus / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D013569:Synapses / Q000502:physiology*; D050599:Vesicular Glutamate Transport Protein 2; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D018091:Receptors, AMPA; C493475:Slc17a6 protein, rat; D050599:Vesicular Glutamate Transport Protein 2; D033921:Vesicular Transport Proteins; C104722:glutamate receptor ionotropic, AMPA 2