Pharmacopsychiatry 2006; 39(3): 88-99
DOI: 10.1055/s-2006-941557
Original Paper
© Georg Thieme Verlag KG Stuttgart · New York

The Comparison of Changes in Behavior, Neurochemistry, Endocrine, and Immune Functions after Different Routes, Doses and Durations of Administrations of IL-1β in Rats

C. Song1 , D. F. Horrobin2 , B. E. Leonard3
  • 1Department of Biomedical Science, AVC, University of Prince Edward Island, Charlottetown, Canada
  • 2Laxdale Ltd., Stirling, Scotland, UK (deceased)
  • 3Institute for Brain and Behavior Research, Section of Neurosciences, University of Maastricht, Maastricht, The Netherlands
Further Information

Publication History

Received: 13.5.2005 Revised: 31.11.2005

Accepted: 21.12.2005

Publication Date:
23 May 2006 (online)

Preview

Background: Increased interleukin-1β (IL-1) in the brain and periphery has been associated with neurodegenerative and psychiatric disorders. However, results from different IL-1 sources, administrating routes, doses and treatment duration were inconsistent and confused. The neuroendocrine-immune mechanism by which IL-1-induced behavioral changes occur is still unclear. Methods: In the present study, the acute and sub-chronic effects of rat recombinant IL-1, following either intraperitoneal (ip) or intracerebroventricular (icv) injection, were studied on the behavior, corticosterone secretion, peripheral inflammatory responses and brain monoamines. Results: In the open field apparatus, IL-1 (ip) increased locomotor activity but decreased the activity following icv administration. IL-1 had a greater anxiogenic effect in the elevated plus maze after icv than after ip administration. In the Morris water maze spatial memory was only impaired following sub-chronic and icv administration. Both acute and sub-chronic IL-1 increased the serum corticosterone concentration and decreased the release of the anti-inflammatory cytokine IL-10 from whole blood cultures. However, centrally administered IL-1 increased, while peripherally administered decreased, the release of PGE2 from blood cultures. After sub-chronic administration, the noradrenaline concentration was decreased in several limbic regions, while the turnovers of serotonin and dopamine were increased. Discussion: These results suggest that 1) IL-1 effects depended on the dose, route and duration of administration, and 2) IL-1 enhances the responsiveness of rats to stressful environmental stimuli. In addition, the sub-chronic administration of IL-1 induces behavioral, neurotransmitter, hormonal and immune changes that may be causally implicated in the mechanism of some of psychiatric disorders such as depression.

References

Cai Song M.D., Ph. D.

Department of Biomedical Science

AVC

University of Prince Edward Island

550 University Ave.

Charlottetown

Canada C1A 4P3

Phone: +1 902 566 7977

Fax: +1 902 569 4289

Email: cai.song@nrc.gc.ca