Effects of seganserin, a 5-HT2 antagonist, and temazepam on human sleepsstages and EEG power spectra

Abstract

The effects of seganserin, a specific 5HT 2 antagonist, on human sleep were assessed in two experiments and compared to the effects of temazepam and sleep deprivation. During daytime recovery sleep after sleep deprivation, seganserin did not significantly enhance visually scored slow wave sleep (SWS, stages 3 + 4) or the EEG power density in the delta frequencies. Under these conditions temazepam reduced the power density in the delta and theta frequencies. During nighttime sleep after a nap in the evening, seganserin caused an increase in SWS, a reduction in intermittent wakefulness, and an enhancement of the power density in the delta and theta frequencies during non-rapid eye movement (NREM) sleep. Temazepam induced a reduction in the power density in the delta and theta frequencies. It is concluded that the 5HT 2 antagonist, seganserin, can induce SWS. However, since the spectral results showed that the changes in the sleep EEG were not identical to those induced by sleep deprivation it seems premature to conclude that 5HT 2 receptors are primarily involved in NREM sleep regulation.

Changes of Sleep Architecture, Spectral Composition of Sleep EEG, the Nocturnal Secretion of Cortisol, ACTH, GH, Prolactin, Melatonin, Ghrelin, and Leptin, and the DEX-CRH Test in Depressed Patients during Treatment with Mirtazapine

“…In qEEG, the selective 5-HT2 antagonists seganserin and ritanserin prompted a bimodal increase of spectral power in the lower delta (0.5-1 Hz) and theta (5-8 Hz) frequencies range with a trough at about 4 Hz (Idzikowski et al, 1986;Dijk et al, 1989;Brandenberger et al, 1996). The changes of sleep architecture and qEEG in the delta and theta range in the present study are in accordance with these reports.…”

“…For a detailed discussion of this methodological problem, see Van Bemmel et al (1995). Relative power values are presented in Figures 1 and 2 according to a suggestion by Dijk et al (1989).…”

Serotonin-2 Receptors and Human Sleep Effect of a Selective Antagonist on EEG Power Spectra

“…The principal effect consisted of a massive increase of SWS and SWA. Similar changes had been reported for the less selective 5-HT 2 antagonists ritanserin and seganserin (Idzikowski et al 1986;Declerck et al 1987;Borbély et al 1988;Dijk et al 1989). In previous studies, also a 10-mg dose of the 5-HT 1A agonist ipsapirone enhanced SWA in the first two hours of NREMS (Seifritz et al 1996), yet did not increase SWS (Gillin et al 1994.…”

“…These results and single unit recordings (Ashby et al 1994) support the notion that inhibitory 5-HT 1A receptors and excitatory 5-HT 2 receptors mediate opposite changes. Unlike ritanserin (Borbély et al 1988), seganserin (Dijk et al 1989), and ipsapirone (Tissier et al 1993;Gillin et al 1994Gillin et al , 1996Driver et al 1995), SR 46349B did not influence the amount and the latency to REMS.…”

“…21 , NO . 3 wave activity (SWA; power within 0.75-4.5 Hz) in humans and animals (Idzikowski et al 1986;Borbély et al 1988;Dijk et al 1989). The 5-HT 2 receptor family is subdivided into three specific subtypes (i.e., 5-HT 2A , 5-HT 2B , and 5-HT 2C receptors) (Humphrey et al 1993).…”