Increase in paradoxical sleep after destruction of serotoninergic innervation in the nucleus tractus solitarius of the rat.
The evolution of paradoxical sleep, slow-wave sleep and arterial pressure was studied following microinjection of 5,7-dihydroxytryptamine in the nucleus tractus solitarius in rats. The extent of the lesions was assessed using immunohistochemistry for serotonin. Global lesions of serotoninergic nerve terminals of the intermediate and commissural regions of the nucleus produced an important and long-lasting increase in paradoxical sleep (+50-70%), a decrease in slow-wave sleep (-20%) and a moderate increase of arterial pressure during all states of the sleep-wake cycle. In addition, more discrete lesions indicated that only the lesion of the area near the obex produced the longer term increase of paradoxical sleep whereas only the lesion of the commissural region of the nucleus produced the long-term decrease of slow-wave sleep. These data demonstrate that serotoninergic projections to the nucleus tractus solitarius exert a regulatory influence upon the specific mechanisms responsible for paradoxical sleep and slow-wave sleep in rats. Furthermore, they suggest that serotonin within the nucleus tractus solitarius plays an important role in the homeostatic cardiovascular and sleep-wake-cycle regulation in rats.
INSERM U 288, CHU Pitie Salpetrière, Paris, France.
A
A
Nosjean
M
M
Arluison
R F
RF
Laguzzi
D015116:5,7-Dihydroxytryptamine; D000818:Animals; D001794:Blood Pressure; D002940:Circadian Rhythm; D007150:Immunohistochemistry; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000032:analysis / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
D015116:5,7-Dihydroxytryptamine; D012701:Serotonin