Effect of alpha-adrenoceptor blockade on sleep and wakefulness in the rat

Pharmacol Biochem Behav. 1986 Mar;24(3):613-6. doi: 10.1016/0091-3057(86)90566-6.


Three alpha-adrenoceptor antagonists with different subtype selectivity were administered IP at the beginning of the light period of the illumination cycle to rats whose sleep-wake pattern was subsequently recorded for 12 hours. Yohimbine (1 mg/kg) initially increased active wakefulness but did not affect REM sleep. Phentolamine (10 mg/kg) and prazosin (0.5 and 1.0 mg/kg) increased the amount of REM sleep during the latter half of the light period. The mechanism of this delayed increase in REM sleep may be related to a greater extent of alpha-receptor binding as well as an optimal, moderate concentration of prazosin and phentolamine in the brain during the latter half of the light period.

MeSH terms

  • Adrenergic alpha-Antagonists / pharmacology*
  • Animals
  • Electroencephalography
  • Male
  • Phentolamine / pharmacology
  • Prazosin / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Sleep / drug effects*
  • Sleep, REM / drug effects
  • Wakefulness / drug effects*
  • Yohimbine / pharmacology


  • Adrenergic alpha-Antagonists
  • Yohimbine
  • Prazosin
  • Phentolamine