TITLE:
Neuropeptide Receptors in Pain Circuitries: Useful Targets for CNS Imaging with Non-Peptide Ligands Suitable for PET?
AUTHORS:
Margit Pissarek
KEYWORDS:
Neuropeptide Receptors, PET, Brain, Pain, Spinal Cord
JOURNAL NAME:
World Journal of Neuroscience,
Vol.4 No.4,
August
14,
2014
ABSTRACT: Neuropeptide
receptors of the brain and spinal cord are parts of the pain circuits targeted
by analgesic drugs. Some of these receptors have been found in the central
nervous system as well as in intracranial vascular structures and achieved
revival of attention because of their role in acute and chronic pain syndromes.
A number of them are of high clinical relevance for e.g. migraine. Others
participate in symptoms of rare diseases like amyotrophic lateral sclerosis.
Here we will focus on five of the neuropeptide receptors and their non-peptide
ligands potentially or already successfully used as PET probes. Opioid
receptors and neurotensin receptors are known to mediate analgesic actions.
Bradykinin and calcitonin gene-related peptide (CGRP) receptors are known to be
involved in the regulation of vascular tone and inflammatory responses, and
neurokinin receptors play a role in the occurrence of pain perception in a
rather indirect manner. Most experiences as PET tracers have been gathered with
opioid receptor ligands and neurokinin receptor ligands. The most innovative
fields revealed by the studies summarized in this report are the ligands of κ
opioid receptors and CGRP receptors for which a first PET tracer was presented
recently.