Interleukin-1 induces changes in sleep, brain temperature and
serotonergic metabolism.
Gemma, Carmelina, Luca Imeri, Maria Grazia De Simoni, and Mauro
Mancia.
Istituto di Fisiologia Umana II, Universit[circumflex]e degli
Studi, Milano and Istituto di Ricerche Farmacologiche Mario Negri,
Milano, Italy
APStracts 3:0313R, 1996.
Simultaneous recordings of sleep-wake activity and of serotonergic
metabolism in the Medial Preoptic Area were performed in freely
moving rats after the intracerebroventricular injection of
interleukin-1 (IL-1) at dark onset. IL-1 2.5 ng induced a biphasic
increase in slow wave sleep, and an early increase in serotonergic
metabolism starting 30 min post-injection. Phasic, state-specific
changes (which have been described in spontaneous sleep) were
superimposed on this tonic, overall increase in serotonergic
metabolism. IL-1 25 ng induced an increase in wakefulness and a
delayed increase in serotonergic metabolism, which started 120 min
post-injection. This suggests that the time-course of the
serotonergic activation could play a role in mediating IL-1 effects
on sleep. Both doses of IL-1 induced a similar and significant
increase in brain cortical temperature, suggesting that IL-1 effects
on sleep are not a secondary effect of the increase in cortical
temperature and that the serotonergic system is not involved in IL-1
-induced fever.
Received 23 May 1996; accepted in final form 30 July 1996.
APS Manuscript Number R292-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996