Effects of Chronic Administration of Low-Dose Interleukin-1β on Exploratory Behavior and Spatial Memory in Rats

The actions of chronic i.p. administration of the proinflammatory cytokine interleukin-1β (IL-1β) on exploratory behavior and spatial memory were studied in rats. IL-1β was given at the weakly pyrogenic dose of 0.5 μg/kg daily for 14 days (starting seven days before and continuing through seven days of behavioral testing). Behavior was analyzed 23.5 h after sequential injections of cytokine. A battery of tests was used, including the open field test (on three sequential days), exploration of novel objects, and the Morris water maze. Experimental animals showed a significant decrease in motor activity, a minor increase in anxiety, and suppression of exploratory behavior. Impairments to spatial memory were not seen. © 2016, Springer Science+Business Media New York.