Glu-evoked GABA release is independent of glutamate decarboxylase.

<p>(A) Contour plot representations of gradient enhanced ¹H/¹³C heteronuclear single quantum coherence (¹³C-HSQC) spectra of extracellular fluid sample from rat cerebrocortical NPMV after incubation with [U-¹³C/¹⁵N]Glu for 30 min in control (black) and semicarbazide (SCB)-treated animal (red). GABA resonances (arrows) do not appear in the samples from SCB-treated animal. (B) Elevation of [GABA]_o in acute rat hippocampal slices in control (n = 6) and SCB-treated animals (n = 7; P = 0.54; 145±14% of pre-stimulus control). (C) Intracellular [³H]GABA level as determined by [³H]GABA uptake in the presence of 100 µM NNC-711 in control condition and in SCB-treated animals (n = 3, P = 0.85).