SPECIES-DIFFERENCES IN THE LOCALIZATION OF NEUROPEPTIDE FF RECEPTORS IN RODENT AND LAGOMORPH BRAIN AND SPINAL-CORD

Quantitative in vitro receptor autoradiography of [I-125] [D-Tyr(1),(N Me)Phe(3)] NPFF was used to study the regional distribution of neurope ptide FF receptors in rodent and lagomorph brain. In rat, mouse, rabbi t, and Afghan pika [I-125] [D-Tyr(1),(NMe)Phe(3)] NPFF binding sites w ere enriched in the superficial layers of dorsal horn of the spinal co rd and in parabrachial nucleus, central gray matter, hypothalamus, and reuniens thalamic nucleus. In other neuroanatomical regions, importan t species differences in NPFF receptor patterns are observed. In marke d contrast, the brain and the spinal cord of the Octodon degus are dev oid of NPFF receptors. The present study shows that in different speci es regional variations in brain NPFF receptor binding occur.