Muscarinic cholinergic receptors in human narcolepsy: a PET study

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Published on: January 25, 2016

Y Sudo1, T Suhara, Y Honda

  • 1Division of Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba, Japan. sudo_y@nirs.go.jp

Neurology
|November 18, 1998
PubMed
Abstract

Insights

This study found no difference in muscarinic cholinergic receptors (mAchRs) in drug-free narcolepsy patients. Pharmacotherapy did not alter mAchRs, suggesting they are not the primary target for treating narcolepsy symptoms.

Area of Science:

  • Neuroscience
  • Sleep Medicine
  • Pharmacology

Background:

  • Muscarinic cholinergic receptors (mAchRs) are key in REM sleep regulation.
  • Canine narcolepsy studies indicated elevated mAchRs in the pons.

Purpose of the Study:

  • To examine muscarinic cholinergic receptor (mAchR) function in narcolepsy.
  • To assess the impact of pharmacotherapy on mAchRs in narcolepsy patients.

Main Methods:

  • Positron Emission Tomography (PET) with [11C]N-methyl-4-piperidylbenzilate ([11C]NMPB) was used.
  • mAchRs were measured in the pons, thalamus, striatum, and cerebral cortex.
  • 11 drug-naive/free narcolepsy patients and 21 controls were scanned; 7 patients were rescanned after treatment.

Main Results:

  • No significant differences in [11C]NMPB binding were observed between controls and drug-naive/free narcolepsy patients.
  • On-medication PET scans showed a slight decrease in thalamic [11C]NMPB binding.
  • This decrease was minimal compared to effects seen with anticholinergic drugs.

Conclusions:

  • The findings do not support mAchRs as the primary mechanism for pharmacotherapy-induced clinical improvement in human cataplexy.
  • Further research is needed to elucidate the precise mechanisms of narcolepsy pharmacotherapy.

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