Anti-inflammatory agents attenuate the passive responses of guinea pig pups: evidence for stress-induced sickness behavior during maternal separation.
A previous study found that intracerebroventricular (ICV) infusion of 25 microg of alpha-MSH reduced the passive responses (crouched stance, eye-closing, piloerection) of guinea pig pups during a 3-h isolation in a novel environment. Because alpha-MSH has broad anti-inflammatory properties, the results suggested that proinflammatory factors play a role in mediating the behavior of isolated infants. The present study further investigated this possibility. In Experiment 1, injection of lipopolysacchride (LPS) increased the number of 60-s intervals in which pups expressed the same three responses during a 1-h test, and ICV infusion of alpha-MSH significantly reduced the effect of LPS on crouching and piloerection. In Experiment 2, the prostaglandin synthesis inhibitor indomethacin (10 mg/kg) reduced the number of 60-s intervals in which pups exhibited both crouching and the full suite of passive responses during a 3-h isolation in a novel environment. Together these results provide further support for the hypothesis that the passive behaviors exhibited during prolonged isolation are "stress-induced sickness behaviors" mediated by proinflammatory factors.
Hennessy
Michael B
MB
Department of Psychology, Wright State University, Dayton, OH 45435, USA. michael.hennessy@wright.edu
Schiml-Webb
Patricia A
PA
Miller
Emily E
EE
Maken
Deborah S
DS
Bullinger
Katie L
KL
Deak
Terrence
T
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D006168:Guinea Pigs; D046353:Immobility Response, Tonic / Q000502:physiology*; D007213:Indomethacin / Q000494:pharmacology; D018836:Inflammation Mediators / Q000502:physiology*; D007276:Injections, Intraventricular; D008070:Lipopolysaccharides / Q000276:immunology; D008426:Maternal Deprivation; D012803:Sick Role; D012934:Social Isolation; D018709:Statistics, Nonparametric; D013315:Stress, Psychological / Q000276:immunology* / Q000523:psychology; D000521:alpha-MSH / Q000008:administration & dosage / Q000502:physiology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018836:Inflammation Mediators; D008070:Lipopolysaccharides; D000521:alpha-MSH; D007213:Indomethacin