PD134308 and PD135158 are highly selective CCK-B receptor antagonists and were used
to investigate the role of CCK-B receptors in aversive responding in rodent and primate
models of anxiety. Both PD134308 and PD135158 were as effective as diazepam to
antagonise aversive behaviour in the mouse light/dark discrimination test, in the rat social
interaction and elevated X-maze tests, and in a marmoset 'human threat'model. However,
the CCK-B antagonists were much more potent than diazepam and their effects were …