Presence of γ-aminobutyric acid transporter mRNA in interneurons and principal cells of rat hippocampus

摘要

After release, neurotransmitters are removed from the extracellular space by high-af®nity uptake. Speci®c sodiumdependenttransporters serve this function for the inhibitory transmitter g-aminobutyric acid (GABA). However, it islargely unknown to which proportion GABA is taken up by GABAergic interneurons, glia cells or principal neurons. Weanalyzed 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 hippocampuswhich contribute to the clearance of GABA from the extracellular space