Presynaptic Selectivity of a Ligand for Serotonin 1A Receptors Revealed by In Vivo PET Assays of Rat Brain
Figure 8
Effects of Wf-516 and pindolol on autoradiographic [35S]GTPγS binding in rat brains.
(A) Representative autoradiograms showing radiolabeling with [35S]GTPγS in the hippocampus and raphe nucleus at baseline (control) or in the presence of 1 µM 8-OH-DPAT (full agonist for 5-HT1A receptors), 10 µM Wf-516, 10 µM pindolol and 1 µM WAY-100635 (full antagonist for 5-HT1A receptors). (B) Ratio of [35S]GTPgγS binding to the control level in the hippocampus (left) and raphe nucleus (right). Changes in radiotracer binding were statistically examined using one-way repeated-measures ANOVA followed by least significant difference test. *p<0.01 compared with 1 µM WAY-100635. In the raphe nucleus, a significant interaction between [35S]GTPγS binding and three concentrations each of Wf-516, pindolol and WAY-100635 was demonstrated by two-way repeated-measures ANOVA (p<0.05, F(4,20) = 3.58).