Automatic Synthesis of [(18)F]Altanserin, a Radiopharmaceutical for Positron Emission Tomographic Studies of the Serotonergic Type-2 Receptors.

[(18)F]Altanserin is routinely used in several centers to study the serotonergic type-2 receptors (5HT(2)) with positron emission tomography (PET). An automatic production system allowing the preparation of multimillicurie amounts [>1.5 GBq (40 mCi) EOS, mean radiochemical yield 20 +/- 6% EOB, specific activity >1 Ci/μmol, n = 50] of this radiopharmaceutical within a synthesis time of 90 minutes (quality controls included) is described in this paper.

Attention-dependent changes of activation and connectivity in dichotic listening.

Functional studies of auditory spatial attention generally report enhanced neural responses in auditory cortical regions. However, activity in regions of the spatial attentional network as described in the visual modality is not consistently observed. Data analysis limitations due to oppositely lateralized activity depending on the side of attentional orientation and heterogeneity of paradigms makes it hard to untangle the possible causes of these various activation patterns.

Quantification of 5-HT(1A) receptors in human brain using p-MPPF kinetic modelling and PET.

Serotonin-1A (5-HT(1A)) receptors are implicated in neurochemical mechanisms underlying anxiety and depression and their treatment. Animal studies have suggested that 4-(2'-methoxyphenyl)-1-[2'-[ N-(2"-pyridinyl)- p-[(18)F]fluorobenzamido] ethyl] piperazine ( p-MPPF) may be a suitable positron emission tomography (PET) tracer of 5-HT(1A) receptors. To test p-MPPF in humans, we performed 60-min dynamic PET scans in 13 healthy volunteers after single bolus injection.