Proinflammatory cytokines differentially affect leverpress avoidance acquisition in rats

• Published in: Behavioural brain research 2004-08, Vol.153 (2), p.351-355
• Main Authors: Brennan, Francis X, Beck, Kevin D, Servatius, Richard J
• Format: Article
• Language: English
• Subjects: Animal; Animals; Arousal - drug effects; Association Learning - drug effects; Avoidance Learning - drug effects; Biological and medical sciences; Brain - drug effects; Conditioning; Conditioning, Classical - drug effects; Electroshock; Escape Reaction - drug effects; Escape/avoidance conditioning; Fundamental and applied biological sciences. Psychology; IL-1β; IL-6; Interleukin-1 - pharmacology; Interleukin-6 - pharmacology; Learning. Memory; Male; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - drug effects; Rats; Rats, Sprague-Dawley; Reaction Time - drug effects; Recombinant Proteins - pharmacology; Retention (Psychology) - drug effects; TNFα; Tumor Necrosis Factor-alpha - pharmacology
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2003.12.025

Recent evidence indicates that the pro-inflammatory cytokines (PICs) can affect learning and memory processes. To examine the effect of the PICs on leverpress escape/avoidance conditioning, we injected male Sprague-Dawley rats with IL-1β, IL-6 (both 3.0 μg/kg, i.p.), TNFα (6.0 μg/kg, i.p.) or vehicle, 24 h before a single 4-h session of leverpress escape/avoidance conditioning. The TNFα-treated animals made more avoidance responses and fewer escape responses than controls during the last hour of the session. Further, both TNFα- and IL-1β-treated animals had a higher percent avoidance than controls during the 4th hour of the session. None of the cytokines had an effect on the number of leverpresses during safety, a putative measure of anxiety. Results are discussed in terms of the differential central effects of the pro-inflammatory cytokines and the possible relationship to avoidance conditioning.