Effect of paradoxical sleep deprivation on vasoactive intestinal peptide-like immunoreactivity in discrete brain areas and anterior pituitary of the rat.
To determine whether vasoactive intestinal peptide (VIP) is involved in paradoxical sleep (PS) homeostasis, VIP-like immunoreactivity (VIP-LI) of discrete brain areas was determined by radioimmunoassay after 24 and 48 h of PS deprivation by the watertank technique followed or not by 5 h of sleep rebound. This study was carried out with an environmental control (placed in dry watertank: DWC) and a nonstressed control. Such PS deprivation induced a decrease of VIP content in PS-deprived rats restricted to cortex and anterior pituitary. In the cortex, the decrease in VIP-LI was of the same magnitude after 24 and 48 h of PS deprivation and VIP-LI was normal by 5 h of sleep rebound; as such a decrease was also observed after 48 h in DWC, it could be due to the stress related to the experiment rather than lack of sleep. In the anterior pituitary, the decrease was related to the duration of deprivation with a greater decrease in VIP-LI after 48 than after 24 h of PS deprivation and specifically related to PS deprivation since it was not observed in DWC rats. After 5 h of sleep rebound, recovery of VIP-LI was total in the 24-h experiment and partial in the 48-h one. In all eight other structures studied, VIP was unchanged after experimentation. These results strongly suggest that VIP is not involved in PS homeostasis but as indicated by other experiments more probably in circadian organization of sleep.
Morin
A J
AJ
Laboratoire de Médecine Expérimentale, INSERM U 52-CNRS URA 1195, Université Claude Bernard, Lyon, France.
Denoroy
L
L
Jouvet
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology; D004569:Electroencephalography; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism* / Q000502:physiology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D012892:Sleep Deprivation / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
D014660:Vasoactive Intestinal Peptide