Hunting for cerebral [2-13C]GABA signal derived in vivo from glia-specific substrate [2-13C]acetate
Shen J, Yang J, Li S, Fox S, Bacher J, Innis R
Acetate has been demonstrated to be a glia-specific substrate. Brain [2-13C]GABA signal derived from [2-13C]acetate is a measure of the glutamine-GABA cycle. In this study, spectrally resolved cerebral [2-13C]GABA signal derived from intravenously infused [2-13C]acetate was detected in vivo in the POCE spectra in vigabatrin-treated rats at 11.7 Tesla. However, in the intact brain, the [2-13C]GABA signal derived in vivo from [2-13C]acetate is not significantly above the noise level after extensive signal averaging using either 1H(13C) POCE spectroscopy of rat brain at 11.7 Tesla or 13C(1H) polarization transfer spectroscopy of the monkey brain at 4.7 Tesla.