Glutamate Uptake Triggers Transporter-Mediated GABA Release from Astrocytes

• DOI: 10.1371/journal.pone.0007153
• Publication Date: 2009-09-23T22:00:10Z
• Authors: László Héja; Péter Barabás; Gabriella Nyitrai; Katalin A. Kékesi; Bálint Lasztóczi; Orsolya Tőke; Gábor Tárkányi; Karsten Madsen; Arne Schousboe; Árpád Dobolyi; Miklós Palkovits; Julianna Kardos
• Keywords: GABA transporter; Gamma-Aminobutyric Acid; Synaptic cleft; Glutamate aspartate transporter

Glutamate (Glu) and gamma-aminobutyric acid (GABA) transporters play important roles in regulating neuronal activity. Glu is removed from the extracellular space dominantly by glial transporters. In contrast, GABA mainly taken up neurons. However, transporter subtypes share their localization with expression confined to same subpopulation of astrocytes, raising possibility cooperation between transport processes.Here we used diverse biological models both vitro vivo explore interplay these processes. We found that removal astrocytic triggers an elevation level GABA. This coupling excitatory inhibitory signaling was be independent receptor-mediated depolarization, external presence Ca(2+) glutamate decarboxylase It abolished non-transportable blockers or transporters, suggesting concerted action underlies process.Our results suggest activation release through reversal transporter-mediated represents a direct link neurotransmission may function as negative feedback combating intense excitation pathological conditions such epilepsy ischemia.