Premium
Dose‐dependent effects of the 5‐HT 1A receptor agonist 8‐OH‐DPAT on sleep and wakefulness in the rat
Author(s) -
MONTI JAIME M.,
JANTOS HÉCTOR
Publication year - 1992
Publication title -
journal of sleep research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 117
eISSN - 1365-2869
pISSN - 0962-1105
DOI - 10.1111/j.1365-2869.1992.tb00033.x
Subject(s) - pindolol , wakefulness , agonist , 8 oh dpat , slow wave sleep , non rapid eye movement sleep , dorsal raphe nucleus , medicine , endocrinology , chemistry , sleep onset , 5 ht receptor , serotonin , psychology , receptor , insomnia , pharmacology , neuroscience , serotonergic , electroencephalography
SUMMARY Sleep and wakefulness were studied in rats following administration of a selective 5‐HT 1A agonist (8‐OH‐DPAT), a non‐selective 5‐HT 1A antagonist [(‐) pindolol] and a combination of 8‐OH‐DPAT and (—) pindolol. 8‐OH‐DPAT (1.0–4.0 μg) injected into the dorsal raphe nucleus increased slow‐wave sleep and decreased wakefulness. Administration of the 5‐HT 1A agonist by subcutaneous route induced biphasic effects such that low doses (0.010 mg kg ‐1 ) decreased wakefulness and increased slow‐wave sleep while higher doses (0.375 mg kg ‐1 ) induced opposite effects. REM sleep was suppressed and REM latency was increased, what could be tentatively ascribed to a non‐specific effect (hypothermia). (‐) Pindolol (1.0–4.0 mg kg ‐1 ) induced an initial increase of wakefulness and a decrease of NREM sleep and REM sleep. Thereafter, NREM sleep showed a marked increase while REM sleep remained depressed. Pretreat‐ment with (—) pindolol reversed the effects of both small and large doses of 8‐OH‐DPAT on slow‐wave sleep and wakefulness. The opposite effects, observed on the waking EEG after activation of either serotonin autoreceptors or postsynaptic 5‐HT 1A receptors with adequate doses of 8‐OH‐DPAT, tend to indicate an active role for the 5‐HT 1A receptor in the control of the waking state.