(+)-[11C]galanthamine (3.7 MBq) was administered to seven-week-old male ddY mice. Five animals were then sacrificed by exsanguination at time-points of 2, 5, 15, 30, and 60 min post-administration

The inhibitory activities of (+)-galanthamine against AChE were measured using a modified version of the colorimetric method of Ellman. 2 mkL of a 10-mM solution of (+)-Galanthamine in 0.1 M phosphate buffer (pH 8) was mixed with 190 mkL of AChE solution (extracted from the brain tissue of a 9-week-old rat) in each well of a 96-well titer plate. After the incubation of the titer plate for 30 min at 37 C, 600 mkL of 10-mM 5,50-dithiobis-(2-nitrobenzoic acid) (DTNB), 100 mkL of 150 mM acetylthiocholine iodide and 100 mkL of buffer were successively added. Changes in UV absorbance of the reaction mixture were then measured at 2 min intervals in a 96-well plate reader at 415 nm, three times, consecutively.