Integrative action of receptor mosaics: relevance of receptor topology and allosteric modulators.

After a definition of the receptor mosaic (RM, high order heteromer or homomer) concept, this study analyzes some relevant theoretical aspects related to receptor-receptor interactions (RRIs). In particular, the possible influence of the plasma membrane microdomain on RM integrative functions are discussed. Furthermore, a possible mathematical approach may identify the RM topologies [i.e., the spatial arrangements the receptors (tesserae of the mosaic) can assume within the RM assembly]. Finally, data are presented on homocysteine possible biasing action on the well-characterized heterodimer/receptor mosaic formed by adenosine A2A and dopamine D2 receptors. We discuss how these findings can lead to a new possible approach for developing drugs for the treatment of certain neuropsychiatric disorders.