Pavlovian conditioning of LPS-induced responses: effects on corticosterone, splenic NE, and IL-2 production.
The present study used a taste aversion paradigm to condition lipopolysaccharide (LPS)-induced suppression of splenic lymphocyte interleukin-2 (IL-2) production, with concurrent measurement of corticosterone production and splenic norepinephrine (NE) content). In training, two groups of rats received saccharin and IP LPS in a paired (P) manner and a third group in a specifically unpaired (U) manner. In the test, the unpaired group (group U) and one of the paired (group P) groups were re-exposed (R) to the cue and the other not (NR). An additional group controlled for the effects of cues (conditional stimulus) and fluid deprivation (negative control; NC). A robust taste aversion in the P-R group was accompanied by suppression of IL-2 production, reduced splenic NE content, and elevated corticosterone production, relative to combined controls (i.e., groups U-R, P-NR, and NC). The conditioned modulation of IL-2 secretion, along with the concomitant alteration of adrenocortical and sympathetic mediators, supports the involvement of bidirectional central nervous-immune system pathways in this paradigm.
Janz
L J
LJ
Department of Pathology, University of Manitoba, Winnipeg, Canada.
Green-Johnson
J
J
Murray
L
L
Vriend
C Y
CY
Nance
D M
DM
Greenberg
A H
AH
Dyck
D G
DG
D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D003345:Corticosterone / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects; D007376:Interleukin-2 / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009638:Norepinephrine / Q000096:biosynthesis*; D011863:Radioimmunoassay; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000494:pharmacology; D013154:Spleen / Q000187:drug effects / Q000378:metabolism*; D013549:Sweetening Agents / Q000494:pharmacology; D013649:Taste / Q000187:drug effects
D007376:Interleukin-2; D008070:Lipopolysaccharides; D013549:Sweetening Agents; D012439:Saccharin; D003345:Corticosterone; D009638:Norepinephrine