Presence of gamma-aminobutyric acid transporter mRNA in interneurons and principal cells of rat hippocampus.
After release, neurotransmitters are removed from the extracellular space by high-affinity uptake. Specific sodium-dependent transporters serve this function for the inhibitory transmitter gamma-aminobutyric acid (GABA). However, it is largely unknown to which proportion GABA is taken up by GABAergic interneurons, glia cells or principal neurons. We analyzed the distribution of mRNA for the main GABA-transporter subtype in the hippocampus, GAT-1, in adult rats. Most interneurons were strongly stained for GAT-1 mRNA, indicating re-uptake by the GABA-releasing cells. Surprisingly, prominent signals for GAT-1 were also found throughout the principal cell layers (granule and pyramidal cells). These data indicate that GABA transporters may be present in non-GABAergic projection cells of the rat hippocampus which contribute to the clearance of GABA from the extracellular space.
Frahm
C
C
Johannes-Müller-Institut für Physiologie der Charité, Humboldt-Universität, Tucholskystrasse, 2 10117, Berlin, Germany. chistiane.frahm@charite.de
Engel
D
D
Piechotta
A
A
Heinemann
U
U
Draguhn
A
A
D000818:Animals; D002352:Carrier Proteins / Q000032:analysis*; D005260:Female; D050485:GABA Plasma Membrane Transport Proteins; D006624:Hippocampus / Q000737:chemistry* / Q000166:cytology*; D017403:In Situ Hybridization / Q000379:methods; D007395:Interneurons / Q000737:chemistry*; D008297:Male; D008565:Membrane Proteins / Q000032:analysis*; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins / Q000032:analysis*; D027361:Organic Anion Transporters; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D027361:Organic Anion Transporters; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D012333:RNA, Messenger; C493415:Slc6a1 protein, rat; C079036:Slc6a17 protein, rat; D005680:gamma-Aminobutyric Acid