Enhancing influence of intranasal interleukin-6 on slow-wave activity and memory consolidation during sleep.
The cytokine IL-6 has been considered to exert neuromodulating influences on the brain, with promoting influences on sleep. Sleep enhances the consolidation of memories, and, in particular, late nocturnal sleep also represents a period of enhanced IL-6 signaling, due to a distinctly enhanced availability of soluble IL-6 receptors during this period, enabling trans-signaling of IL-6 to neurons. Thus, a contribution of IL-6 to sleep-dependent memory consolidation is hypothesized. To test this hypothesis, we compared effects of intranasally administered IL-6 (vs. placebo) on sleep-dependent consolidation of declarative (neutral and emotional texts, 2-dimensional object location) and procedural (finger sequence tapping) memories in 17 healthy young men. IL-6 distinctly improved the sleep-related consolidation of emotional text material (P<0.03), which benefits mostly from sleep in the second night-half, in which rapid eye movement sleep (REM) dominates the non-REM-REM sleep cycle. During this second night-half, the amount of electroencephalogram slow-wave activity (0.5-4 Hz) distinctly increased after IL-6 (P<0.01). Other types of memory were not affected. The ability of IL-6 to enhance sleep-associated emotional memory consolidation highlights an example of a functional interaction between the central nervous and immune system.
Benedict
Christian
C
Department of Neuroendocrinology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
Scheller
Jürgen
J
Rose-John
Stefan
S
Born
Jan
J
Marshall
Lisa
L
D000281:Administration, Intranasal; D000328:Adult; D001831:Body Temperature / Q000187:drug effects; D004644:Emotions / Q000187:drug effects; D005221:Fatigue / Q000503:physiopathology; D006801:Humans; D015850:Interleukin-6 / Q000008:administration & dosage*; D008297:Male; D008568:Memory / Q000187:drug effects*; D012890:Sleep / Q000187:drug effects*; D055815:Young Adult
D015850:Interleukin-6