Postnatal development of high-affinity plasma membrane GABA transporters GAT-2 and GAT-3 in the rat cerebral cortex.
We investigated the developmental profile of plasma membrane gamma-aminobutyric acid (GABA) transporters (GATs) GAT-2 and GAT-3 expression by immunocytochemistry with affinity-purified polyclonal antibodies in the rat neocortex. At all developmental ages investigated, GAT-2 ir was prominent in the arachnoid and in the trabeculae of the subarachnoid space, whereas it was weak within the cortical parenchyma; the adult pattern was reached during the third week of postnatal life. GAT-3 ir was present at birth and increased rapidly in the first week, when numerous positive cells were present throughout the cortical layers; at P10, GAT-3-positive cells became less numerous and GAT-3 ir switched to the adult pattern, which was expressed at P20. Confocal and electron microscopic investigations showed that GAT-3 positive cells were both neurons and astrocytes. The present evidence indicates that early in development GAT-3 is abundantly expressed in the cerebral cortex, where its expression appears to correlate with developmental variations in GABA levels, and suggests that it accounts for the largest fraction of GABA transport observed in the neonatal cerebral cortex.
Minelli
Andrea
A
Istituto di Fisiologia Umana, Università di Ancona, Via Tronto 10/A, Torrette di Ancona, I-60020 Ancona, Italy.
Barbaresi
Paolo
P
Conti
Fiorenzo
F
D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005455:Fluorescent Antibody Technique; D050485:GABA Plasma Membrane Transport Proteins; D008297:Male; D026901:Membrane Transport Proteins / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009474:Neurons / Q000648:ultrastructure; D051381:Rats; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D050485:GABA Plasma Membrane Transport Proteins; D026901:Membrane Transport Proteins; C092004:Slc6a13 protein, rat; D005680:gamma-Aminobutyric Acid