injection of 455.1 to 728.2 (mean, 625.9 ± 138.2) MBq [11C](−)McN5652

Binding affinity for (-)-McN5652 was determined at 21°C and 37°C in a final volume of 300 ml of buffer 3, which contained 50 ml of membrane suspension and (-)-McN5652 at one of eight concentrations between 1nM and 10 mkM Nonspecific binding was determined using 1 mM paroxetine as inhibitor. The binding at each concentration was determined with two samples for total binding and one for nonspecific binding. After 3.5 h incubation the samples were filtered using a 24-channel cell harvester Five ml of buffer 3 (20°C) was added to each sample, which was then filtered through Whatman GF/B glass-fiber filters and washed with 20 ml buffer 3. The filters had been soaked with 0.5% polyethylenimine prior to filtration in order to reduce and stabilize nonspecific binding to the filters. The filters were dried overnight and counted in Ultima Gold