Psychotomimetic σ-opiates and PCP

Psychotomimetics including phencyclidine (PCP) and N-allylnormetazocine (SKF 10047) were thought to act at a single recognition site termed the σ/PCP receptor. Recent developments reveal the existence of two distinct sites of differing pharmacology and anatomical localization. Philip Beart and colleagues outline evidence favouring the existence of independent sites and discuss molecular interactions of psychotomimetic ligands. They report that while the PCP site is associated with the NMDA subtype of excitatory amino acid receptor, further insights into the behavioural actions of these psychotomimetics must await the definition of the functional relevance of the high affinity (+)SKF 10047/σ site.