The effects of local microinjection of selective dopamine D1 and D2 receptor agonists and antagonists into the dorsal raphe nucleus on sleep and wakefulness in the rat

Behav Brain Res. 2018 Feb 26:339:11-18. doi: 10.1016/j.bbr.2017.11.006. Epub 2017 Nov 11.

Abstract

The effects of the dopamine (DA) D1 and D2 receptor agonists SKF38393, bromocriptine and quinpirole, respectively, on spontaneous sleep were analyzed in adult rats prepared for chronic sleep recordings. Local administration of the DAergic agonists into the dorsal raphe nucleus (DRN) during the light phase of the light-dark cycle induced a significant reduction of rapid-eye movement sleep (REMS) and the number of REM periods. Additionally, bromocriptine and quinpirole significantly increased wakefulness (W). Opposite, the microinjection into the DRN of the DA D1 and D2 receptor antagonists SCH23390 and sulpiride, respectively, significantly augmented REMS and the number of REM periods. Pretreatment with SCH23390 and sulpiride prevented the effects of SKF38393 and bromocriptine, respectively, on sleep variables. Our results tend to indicate that DAergic neurons located in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) contribute to the regulation of predominantly W and REMS by DRN serotonergic neurons.

Keywords: Dopamine D1 receptor; Dopamine D2 receptor; Dorsal raphe nucleus; REM sleep; Serotonin; Wakefulness.

MeSH terms

  • Animals
  • Dopamine / pharmacology
  • Dopamine D2 Receptor Antagonists / administration & dosage
  • Dopamine D2 Receptor Antagonists / pharmacology*
  • Dorsal Raphe Nucleus / drug effects
  • Male
  • Neurons / drug effects
  • Neurons / physiology
  • Rats, Wistar
  • Receptors, Dopamine D1* / agonists
  • Receptors, Dopamine D1* / antagonists & inhibitors
  • Receptors, Dopamine D2 / agonists*
  • Serotonin / pharmacology
  • Sleep / drug effects*
  • Sleep / physiology
  • Sleep, REM / drug effects
  • Sleep, REM / physiology
  • Wakefulness / drug effects*
  • Wakefulness / physiology

Substances

  • Dopamine D2 Receptor Antagonists
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Serotonin
  • Dopamine