Analysis of the in-vivo GABA_B receptor relocalization and oligomerization in chronic pain conditions using spatial intensity distribution analysis

The response to the synaptic release of γ-Aminobutyric acid (GABA) in the central nervous system is mediated by the GABA_B receptor, inter alia dependent on the formation of receptor oligomers. Spatial intensity distribution analysis (SpIDA) is an image analysis method measuring the oligomerization and density of proteins. It was used to quantify the oligomerization of GABA_B receptors in the rodent spinal cord under conditions of chronic pain and inflammation. SpIDA reports a lowered density of tetrameric GABA_B receptor entities in GABAergic neurons of the dorsal horn under these conditions compared to sham samples. The soma of neurons in the ventral horn is shown to be populated by single entities of the GABA_B receptor. The findings underline the role of receptor oligomerization, as well as the membrane environment in regulating receptor function.