Cooling of the nucleus raphe dorsalis induces sleep in the cat.
Localized moderate cooling (+10 degrees C) of the anterior and ventral part of the raphe dorsalis induced cortical synchronization and ponto-geniculo-occipital (PGO) waves followed sometimes by paradoxical sleep. Cooling the region of the raphe magnus produced cortical arousal. After depletion of brain 5-hydroxytryptamine (5-HT) by para-chlorophenylalanine, cooling the raphe dorsalis resulted in muscle atonia and bursts of high frequency PGO waves but not in cortical synchronization. Following restoration of brain 5-HT by intravenous administration of 5-hydroxytryptophan, cooling again produced cortical synchronization and PGO waves as in the control experiments, but with a diminishing efficacy during repetitive cooling episodes.
Cespuglio
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Department of Experimental Medicine, University Claude Bernard, 8, Avenue Rockefeller, 69373 Lyon Cedex 2 France.
Walker
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Gomez
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ME
Musolino
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