Vol. 280, Issue 2, R398-R403, February 2001
Sleep changes induced by lipopolysaccharide in the rat are
influenced by age
Thomas
Schiffelholz1 and
Marike
Lancel2
1 Department of Psychiatry, University of Kiel, 24115 Kiel;
and 2 Max-Planck Institute of Psychiatry, 80804 Munich,
Germany
In mammals, aging is associated with immune senescense.
To examine whether the sleep changes occurring during immune challenge are affected by age, we assessed sleep alterations induced by the
administration of lipopolysaccharide (LPS) in young and middle-aged rats. During vehicle, the middle-aged rats exhibited less pre-rapid eye
movement sleep (pre-REMS) as well as REMS, due to a smaller number and
shorter duration of REMS episodes, than young rats. LPS elevated body
temperature, increased non-REMS, and suppressed both pre-REMS and REMS
in the young as well as in the middle-aged rats. However, in the young
animals, LPS significantly enhanced slow-wave activity in the
electroencephalogram (EEG) within non-REMS, reflecting an increase in
sleep intensity. In contrast, LPS attenuated EEG power in most
frequency bands in the older animals. This finding indicates
age-related changes in the modulation of sleep by LPS.
EEG spectral analysis; aging
