Central blockade of IL-1 does not impair taste-LPS associative learning.
After saccharin intake is associated with the consequences of peripheral lipopolysaccharide (LPS) administration, rats develop a strong conditioned avoidance behavior against this gustatory stimulus. To investigate the role of central interleukin-1 (IL-1) as a key signal during taste-LPS engram formation, rats were chronically infused with IL-1 receptor antagonist into the lateral ventricle of the brain before, during and after a single association trial. The results indicate that a stable taste-LPS engram can be formed even under the chronic blockade of central IL-1 signaling during engram formation and consolidation. More importantly, our data show that animals which did not experience a fever response during association phase (due to the LPS encounter) were unable to elicit hyperthermia as part of the conditioned response. These data indicate that pairing a relevant taste stimulus with an immune challenge, such as LPS, might result in the formation of multiple engrams, specifically codifying independent information.
Pacheco-López
Gustavo
G
Chair of Psychology and Behavioral Immunobiology, Institute for Behavioral Sciences, ETH Zurich, Zurich, Switzerland. pacheco@ifv.gess.ethz.ch
Niemi
Maj-Britt
MB
Kou
Wei
W
Baum
Sven
S
Hoffman
Marcus
M
Altenburger
Pia
P
del Rey
Adriana
A
Besedovsky
Hugo O
HO
Schedlowski
Manfred
M
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D001831:Body Temperature / Q000187:drug effects / Q000276:immunology; D005334:Fever / Q000139:chemically induced / Q000276:immunology*; D007249:Inflammation / Q000139:chemically induced / Q000276:immunology*; D018836:Inflammation Mediators / Q000494:pharmacology; D007276:Injections, Intraventricular; D053590:Interleukin 1 Receptor Antagonist Protein / Q000494:pharmacology; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D015213:Neuroimmunomodulation / Q000187:drug effects / Q000276:immunology; D051381:Rats; D013649:Taste / Q000187:drug effects / Q000276:immunology*
D018836:Inflammation Mediators; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D008070:Lipopolysaccharides