Inhibition of glutamate/glutamine cycle in vivo results in decreased benzodiazepine binding and differentially regulated GABAergic subunit expression in the rat brain.

Purpose: The astrocytic enzyme glutamine synthetase (GS) is a key regulator of glutamate and γ-aminobutyric acid (GABA) metabolism in the glutamate/glutamine cycle (GGC). Inhibition of GS results in changes of neurotransmitter release and recycling. However, little is known about the influence of GGC on neurotransmitter receptor expression.

Fast, quantitative in situ hybridization of rare mRNAs using 14C-standards and phosphorus imaging.

The use of radiolabelled probes for in situ hybridization (ISH) bears the advantage of high sensitivity and quantifiability. The crucial disadvantages are laborious hybridization protocols, exposition of hybridized sections to film for up to several weeks and the time consuming need to prepare tissue standards with relatively short-lived isotopes like (33)P or (35)S for each experiment. The quantification of rare mRNAs like those encoding for subunits of neurotransmitter receptors is therefore a challenge in ISH.