IL-4 Knock Out Mice Display Anxiety-Like Behavior

• Published in: Behavior genetics 2015-07, Vol.45 (4), p.451-460
• Main Authors: Moon, Morgan L., Joesting, Jennifer J., Blevins, Neil A., Lawson, Marcus A., Gainey, Stephen J., Towers, Albert E., McNeil, Leslie K., Freund, Gregory G.
• Format: Article
• Language: English
• Subjects: Animals; Anxiety; Anxiety - genetics; Behavior, Animal; Behavioral Science and Psychology; Clinical Psychology; Exploratory Behavior; Health Psychology; Inflammation; Interleukin-4 - genetics; Male; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Knockout; Original Research; Psychology; Public Health; Social Behavior; Swimming
• ISSN: 0001-8244; 1573-3297
• DOI: 10.1007/s10519-015-9714-x

Inflammation is a recognized antecedent and coincident factor when examining the biology of anxiety. Little is known, however, about how reductions in endogenous anti-inflammatory mediators impact anxiety. Therefore, mood- cognition- and anxiety-associated/like behaviors were examined in IL-4 knock out (KO) mice and wild-type (WT) mice. In comparison to WT mice, IL-4 KO mice demonstrated decreased burrowing and increased social exploration. No differences were seen in forced swim or saccharine preference testing. IL-4 KO mice had similar performance to WT mice in the Morris water maze and during object location and novel object recognition. In the elevated zero-maze, IL-4 KO mice, in comparison to WT mice, demonstrated anxiety-like behavior. Anxiety-like behavior in IL-4 KO mice was not observed, however, during open-field testing. Taken together, these data indicate that IL-4 KO mice display state, but not trait, anxiety suggesting that reductions in endogenous anti-inflammatory bioactives can engender subtypes of anxiety.