Model of the GABA-A receptor adapted from the review by Harward and McNamara. The GABA-A receptor consists of five GABA receptor subunits. The benzodiazepine receptor is independent of the binding site for GABA (allosteric). DBI gene products are likely to have endozepine action, i.e. they bind to the benzodiazepine receptor and either enhance (PAM) or reduce (NAM) the action of GABA.