Candidate 3-benzazepine-1-ol type GluN2B receptor radioligands (11C-NR2B-Me enantiomers) have high binding in cerebellum but not to σ1 receptors

Abstract

Key points Question: Do GluN2B radioligands 11C-NR2B-Me enantiomers show cross-binding with σ1 receptors in brain in vivo? Pertinent findings: 11C-(+)-NR2B-Me, 11C-(−)-NR2B-Me, 11C-(S)-NR2B-SMe, and 11C-(R)-NR2B-SMe give specific signals in whole rat brain that could be pre-blocked and displaced using ligands that specifically target GluN2B receptors, but not by σ1 ligand FTC-146. Implications for patient care: 11C-(−)-NR2B-Me does not show cross-binding with σ1 receptor in rat brain using PET imaging. This radioligand may be promising for human PET imaging.

Keywords

• GluN2B
• NMDA receptor
• σ1 receptor
• NR2B-Me
• PET