In vivo serotonin-sensitive binding of [11C]CUMI-101: a serotonin 1A receptor agonist positron emission tomography radiotracer.

Positron emission tomography studies of 5-hydroxytryptamine (5-HT)(1A) receptors have hitherto been limited to antagonist radiotracers. Antagonists do not distinguish high/low-affinity conformations of G protein-coupled receptors and are less likely to be sensitive to intrasynaptic serotonin levels. We developed a novel 5-HT(1A) agonist radiotracer [(11)C]CUMI-101.

In vivo assessment of [11C]MRB as a prospective PET ligand for imaging the norepinephrine transporter.

Purpose: Antagonism of norepinephrine reuptake is now an important pharmacological strategy in the treatment of anxiety and depressive disorders, and many antidepressants have substantial potential occupancy of the norepinephrine transporter (NET) at recommended dosages. Despite the importance of understanding this transporter's role in psychiatric disease and treatment, a suitable radioligand for studying NET has been slow to emerge. (S,S)-Methylreboxetine (MRB) is among the more promising ligands recently adapted for positron emission tomography (PET), and the present study aimed to evaluate its potential for use in higher primates.

In vitro and in vivo evaluation of [11C]MPEPy as a potential PET ligand for mGlu5 receptors.

Excessive activation via the metabotropic glutamate receptor subtype 5 (mGluR(5)) has been implicated in depression, neuropathic pain and other psychiatric, neurological and neurodegenerative diseases. A mGluR(5) radioligand for in vivo quantification by positron emission tomography (PET) would facilitate studies of the role of this receptor in disease and treatment. 3-Methoxy-5-pyridin-2-ylethynylpyridine (MPEPy), a selective and high-affinity antagonist at the mGluR(5) receptor was selected as a candidate ligand; a recent publication by Yu et al.