Age stability of human brain 5-HT terminals studied with [3H]paroxetine binding.

The effect of age on serotonin uptake sites labeled with [3H]paroxetine was studied in two sets of brains. The first set included 28 subjects (19 males and 9 females) between the ages 0 and 100 years. The cortex of cingulate gyrus and the amygdala were studied. No age-related changes in binding capacity (Bmax) or binding affinity (Kd) were noted. In the second set, the frontal cortex and hypothalamus from 22 subjects (18 males and 4 females) between 16 and 75 years were studied. No age-related changes in the binding were observed. The interval between death and freezing of the tissue did not influence the binding. Regarding the [3H]paroxetine binding as an indirect marker for 5-HT terminals, the data suggest a stability of 5-HT terminals with increasing age in the human brain.