EFFECT OF AGING IN HUMAN CORTICAL PRESYNAPTIC AND POSTSYNAPTIC SEROTONIN BINDING-SITES

5-HT1A, 5-HT1D, 5-HT2 binding sites and affinity and 5-HT uptake sites were simultaneously determined in frontal cortex samples from 23 cont rol subjects, aged 16-75 years. A significant reduction in the number of 5-HT1D and 5-HT2 binding sites was found with regard to age, togeth er with a significant decrease in the 5-HT2 binding affinity. It is su ggested that the total 5-HT, age-related loss described in previous st udies could be ascribed to the 5-HT1D subtype. Furthermore, aging does not seem to be associated with a reduced cortical serotonergic innerv ation, as indicated by the stability of the [H-3]paroxetine-labeled 5- HT uptake sites.