G-protein-coupled receptors (GPCRs) represent the largest family of receptors involved in transmembrane signaling. Although these receptors were generally believed to be monomeric entities, accumulating evidence supports the presence of GPCRs in multimeric forms. Here, using immunoprecipitation as well as time-resolved fluorescence resonance energy transfer to assess protein-protein interactions in living cells, we unambiguously demonstrate the occurrence of dimerization of the human histamine H 1 receptor. We also show the presence of domain-swapped H 1 receptor dimers in which there is the reciprocal exchange of transmembrane domain TM domains 6 and 7 between the receptors present in the dimer. Mutation of aspartate 107 in transmembrane (TM) 3 or phenylalanine 432 in TM6 to alanine results in two radioligand-binding-deficient mutant H 1 receptors. Coexpression of H 1

A mid-scalar electrode array achieves a stable position in the cochlea in a small but representative group of patients. The methods applied in this work can be used for providing postoperative feedback for surgeons and for benchmarking electrode designs.

IntroductionThe goal of this investigation was to compare fusion of sequential cone beam computerized tomography (CT) volumes to the gold standard (fiducial registration) in order to be able to analyze clinical cochlear implant (CI) migration with high accuracy in three dimensions.Materials and methodsPaired cone beam CT volumes were performed on five human cadaver temporal bones and one human subject. These volumes were fused using 3D Slicer 4 and BRAINSFit software. Using a gold standard fiducial technique, the accuracy, robustness, and performance time of the fusion process were assessed.ResultsThis proposed fusion protocol achieves a subvoxel median Euclidean distance of 0.05 mm in human cadaver temporal bones and 0.16 mm (mean) when applied to the described in vivo human synthetic data set in over 95% of all fusions. Performance times are <2 min.ConclusionHere, a new and validated method based on existing techniques is described, which could be used to accurately quantify migration of CI electrodes.