Morphine-like effects of clonidine on the EEG, slow wave sleep and behavior in the dog

Wallace B. Pickworth, Lawrence G. Sharpe, Vaikunth N. Gupta

Research output: Contribution to journalArticlepeer-review


EEG, behavioral and autonomic effects of morphine and clonidine were compared in the unrestrained beagle dog placed in a dimly-lit, sound-attenuated chamber equipped with video monitors. Intravenous (i.v.) morphine (0.5, 1 and 2 mg/kg) and clonidine (11, 33 and 100 μg/kg) caused parallel dose-related increases in NREM sleep with clonidine being 43 times more potent than morphine. Other similar effects were: an initial transient EEG-behavioral dissociation, increases in spectral power (8-16 Hz); decreases in temperature and heart and respiratory rates; emesis, miosis and salivation. Intraventricular (i.v.t.) morphine (33, 100 and 300 μg) and clonidine (10 and 30 μg) caused qualitatively similar EEG, sleep and behavioral effects. Naloxone (30 μg/kg i.v.) prevented EEG synchrony and behavioral effects of i.v. morphine (1 mg/kg) but not those of i.v. clonidine (100 μg/kg). Yohimbine pretreatment (0.1 mg/kg i.v.) was more effective in antagonizing clonidine than morphine. These results suggest that morphine and clonidine induce similar EEG, behavioral and autonomic effects through actions upon different receptors on the same or parallel neural pathways. The results further emphasize the importance of an α2-adrenergic-opiod interaction to regulate sleep in the dog.

Original languageEnglish (US)
Pages (from-to)551-557
Number of pages7
JournalEuropean Journal of Pharmacology
Issue number4
StatePublished - Jul 30 1982
Externally publishedYes


  • Clonidine
  • Intraventricular injections
  • Morphine
  • Naloxone
  • Sleep
  • Yohimbine

ASJC Scopus subject areas

  • Pharmacology


Dive into the research topics of 'Morphine-like effects of clonidine on the EEG, slow wave sleep and behavior in the dog'. Together they form a unique fingerprint.

Cite this