Yes, exactly it´s a coiled "blob" of protein with some sites, that happen to react nicely with the charges of parts of the drug
´s molecule -it´s called allosteric interaction, moving around some bonds of the receptor-sides molecules, and -no, it doesn´t happen necessarily in the cleft, although this is where neurotransmitters effects are taking place, (I´m sorry I didn´t get the translations for "synaptischer spalt") it´s more at the axon and the praesynaptic locus, the place, where the vesicles are and some ionophores.
for example benzos
doesn´t dock onto a special benzo
-rezeptor, they do, because we called it that way in a receptor-finding and naming mania, but
it has affinities to at least three other sites including the GABA receptor.
There are also sites in this region for depressants
, close to steroids and opioid
binding sites, etc ... and if one part is altered the whole system may/might happen to function in a different manner, than befor, with other sensitivity to other neurotransmitters and so on...