title: Psychogenetically selected (Roman high- and low-avoidance) rats differ in 24-hour sleep organization.
abstract: A comparison of sleep organization in Roman high-(RHA/Verh) and low-(RLA/Verh) avoidance rats, which differ in the way they respond to environmental stimuli and in several neuroendocrine and neurochemical parameters, was carried out. EEG-sleep recordings were obtained from adult males over 12:12 light-dark periods to determine how these two psychogenetically selected rat lines might also differ in their sleep-wake cycle. There was no significant difference in total sleep time between the two lines. However, the (hypoemotional) RHA/Verh rats showed an overall increase (percentage of total sleep) in paradoxical sleep (PS) duration, with a concomitant decrease in slow-wave sleep (SWS). During the dark phase, RHA/Verh rats showed a shorter PS latency and a larger number of PS episodes. Hourly sleep scoring also revealed a more discontinuous pattern (total sleep and PS vs. SWS) during the dark phase in RHA/Verh rats. In relation to recognized neurochemical and neuroendocrine differences between them, these rat lines may prove useful in investigations of the neurobiological mechanisms underlying sleep regulation.
authors.affiliation: Department of Psychiatry, University Hospital of Geneva, Chêne-Bourg, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Steimer
authors.forename: A
authors.initials: A
authors.lastname: Python
authors.forename: P
authors.initials: P
authors.lastname: Driscoll
authors.forename: Z
authors.initials: Z
authors.lastname: de Saint Hilaire
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D005824:Genetics, Behavioral; D008027:Light; D008297:Male; D051381:Rats / Q000235:genetics* / Q000523:psychology*; D012641:Selection, Genetic; D012894:Sleep Stages / Q000502:physiology*