Normal densities of 5-HT₃ receptor recognition sites in alzheimer's disease

THE present studies investigate the possible difference in 5-HT₃ receptor recognition site density in amygdaloid and hippocampal homogenates from patients with Alzheimer’s disease compared with age-matched controls. The 5-HT₃ receptor recognition site radioligand [³H]-(S)-zacopride identified a comparable density of specific sites (defined by granisetron 10.0 μM) in tissues obtained from patients with Alzheimer’s disease as compared to age-matched controls (amygdala, B_max; 41 ± 4 and 43 ± 9; hippocampus, B_max„ 59 ± 9 and 51 ± 9 fmol mg^-3 protein; tissue from Alzheimer’s disease patients and age-matched controls, respectively, mean ± s.e.m., n = 7-8). These results suggest that the density of 5-HT₃ receptor recognition sites labelled by [³H]-(S)-zacopride are not altered in the amygdala and hippocampus of patients with Alzheimer’s disease.