Relationship between in Vivo Occupancy at the Dopamine Transporter and Behavioral Effects of Cocaine, GBR 12909 [1-{2-[Bis-(4-fluorophenyl)methoxy]ethyl}-4-(3-

Analogs of benztropine (BZT) bind to the dopamine (DA) trans-porter and inhibit DA uptake but often have behavioral effects that differ from those of cocaine and other DA-uptake inhibi-tors. To better understand these differences, we examined the relationship between locomotor-stimulant effects of cocaine, 1-{2-[bis-(4-fluorophenyl)methoxy]ethyl}-4-(3-phenylpropyl)-piperazine (GBR 12909), and BZT analogs [(3-[bis(4-fluorophenyl)methoxy]-tropane) (AHN 1-055) and (N-allyl-3-[bis(4-fluorophenyl)methoxy]-tropane) (AHN 2-005)] and their in vivo displacement of the DA transporter ligand [125I]3-(4-iodophenyl)-tropan-2-carboxylic acid isopropyl ester hydro-chloride (RTI-121) in striatum. Cocaine, GBR 12909, and BZT analogs each displaced [125I]RTI-121 and stimulated locomotor activity in a dose- and time-dependent manner. The tim