The serotonergic system may be involved in the sleep-inducing action of oleamide in rats

Naunyn Schmiedebergs Arch Pharmacol. 2003 Dec;368(6):457-62. doi: 10.1007/s00210-003-0843-z. Epub 2003 Nov 13.

Abstract

The mechanism underlying the sleep-inducing effect of oleamide, an endogenous fatty acid amide, was studied in rats. Animals implanted with cerebrocortical and dorsal neck muscle electrodes were monitored continuously by electroencephalograph (EEG) and electromyograph (EMG) for 4 h after i.p. or s.c. injection of drugs. Oleamide induced a dose-dependent increase in slow-wave sleep (SWS), a decrease in wakefulness (W) and sleep latency, but had no effect on rapid-eye-movement sleep (REMS). The oleamide-induced increase in SWS was prevented by 5-HT reuptake inhibitors such as fluoxetine or fenfluramine and by agonists at 5-HT(1A) receptors such as buspirone or 8-hydroxy-2-(di- N-propylamino) tetralin (8-OH-DPAT). Moreover, the selective 5-HT(1A) receptor antagonist WAY100635 markedly antagonized the suppression of the oleamide-induced increase in SWS by 8-OH-DPAT. These data provide the first behavioural evidence that the serotonergic system may be involved in the sleep-inducing action of oleamide in rats.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / antagonists & inhibitors
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology
  • Animals
  • Buspirone / pharmacology
  • Fenfluramine / pharmacology
  • Fluoxetine / pharmacology
  • Hypnotics and Sedatives / pharmacology*
  • Male
  • Neural Pathways / drug effects*
  • Neural Pathways / physiology
  • Oleic Acids / antagonists & inhibitors
  • Oleic Acids / pharmacology*
  • Piperazines / pharmacology
  • Pyridines / pharmacology
  • Rats
  • Rats, Wistar
  • Serotonin / physiology*
  • Serotonin Antagonists / pharmacology
  • Serotonin Receptor Agonists / pharmacology
  • Serotonin Uptake Inhibitors / pharmacology
  • Sleep / drug effects*
  • Sleep / physiology
  • Sleep, REM / drug effects
  • Sleep, REM / physiology
  • Wakefulness / drug effects
  • Wakefulness / physiology

Substances

  • Hypnotics and Sedatives
  • Oleic Acids
  • Piperazines
  • Pyridines
  • Serotonin Antagonists
  • Serotonin Receptor Agonists
  • Serotonin Uptake Inhibitors
  • Fluoxetine
  • Fenfluramine
  • Serotonin
  • N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • oleylamide
  • Buspirone