INTACT BRAIN-SEROTONIN SYSTEM IN VASCULAR DEMENTIA

Pre- and postsynaptic elements of the 5-hydroxytryptamine (5-HT, serot onin) system were studied in a control group and in patients with vasc ular dementia (VAD). The 5-HT uptake site was used as a presynaptic ma rker for 5-HT terminals and 5-HT1A and 5HT2 receptors were used as pos tsynaptic markers. The binding sites were quantified with radioligand binding techniques, where the radioligands used were [H-3]paroxetine, [H-3]8-OH-DPAT and [H-3]ketanserin, respectively. The presynaptic upta ke site was studied in frontal and temporal cortices and caudate nucle us. 5-HT1A and 5-HT2 receptors were studied only in frontal and tempor al cortices. There were no differences between control and VAD groups in any of the regions investigated with respect to the number of bindi ng sites (B-max) and binding affinity (K-d). This indicates that both pre- and postsynaptic parts of the 5-HT system are intact in these bra in areas in VAD.