Effects of ageing on serotonin transporters in healthy females

The effect of ageing on brain serotonin transporters was evaluated in 19 he althy female volunteers (age range 22-74 years) using single-photon emissio n tomography and [I-123]nor-beta -CIT. The study subjects were scanned 0.3, 3, 6 and 23 h after injection of 185 MBq of [I-123]nor-beta -CIT. The rati o of the distribution volume for tracer in the midbrain to that in the cere bellum minus 1 was used as an index for serotonin transporter binding. An a ge-related decline of 2% per decade (r=-0.47; P <0.05) was found in the mid brain. The decline in [I-123]nor-beta -CIT binding in the serotonin transpo rter-rich area is much less than that in dopamine transporters in the stria tum (6% per decade).