Intact brain serotonin system in vascular dementia.

Pre- and postsynaptic elements of the 5-hydroxytryptamine (5-HT, serotonin) system were studied in a control group and in patients with vascular dementia (VAD). The 5-HT uptake site was used as a presynaptic marker for 5-HT terminals and 5-HT1A and 5HT2 receptors were used as postsynaptic markers. The binding sites were quantified with radioligand binding techniques, where the radioligands used were [3H]paroxetine, [3H]8-OH-DPAT and [3H]ketanserin, respectively. The presynaptic uptake site was studied in frontal and temporal cortices and caudate nucleus. 5-HT1A and 5-HT2 receptors were studied only in frontal and temporal cortices. There were no differences between control and VAD groups in any of the regions investigated with respect to the number of binding sites (Bmax) and binding affinity (Kd). This indicates that both pre- and postsynaptic parts of the 5-HT system are intact in these brain areas in VAD.