ABSTRACT
GABAA-receptors are formed by the assembly of various subunits which, in mammalian brain, are encoded by a total of 17 different genes (1-6, 1-3, 1-3, , , 1-3) (Möhler et al., 1997; Möhler, 2001; Sieghart, 1995; MacDonald et al., 1994). In heterologous expression systems, no major restrictions for the combinatorial assembly of the subunits were apparent. However, in vivo, the expression of GABAA-receptor subunits is regulated in an ontogenetic and cell-specific manner providing particular populations of neurons with distinct sets of GABAA-receptor subtypes (Fritschy and Möhler, 1995). The process of receptor assembly is expected to include specific interactions among the constituent subunits. These interactions may govern not only the subunit stoichiometry but also the formation and membrane targeting of multiple GABAAreceptors in a single cell. The distinct targeting of receptor subtypes is considered to serve specific functions in regulating complex behavior and particular drug actions. Thus, the genetic dissection of GABAA-receptors is expected to provide new insights into the function of the GABAA-receptor system.
