Skip to main content
. Author manuscript; available in PMC: 2017 Aug 1.
Published in final edited form as: Brain Behav Immun. 2016 Apr 9;56:325–334. doi: 10.1016/j.bbi.2016.04.005

Figure 1.

Figure 1

Experimental Design of Experiment 1. Following a surgery recovery period, rats were conditioned to associate a heroin injection with a distinct context. Rats in one group received an infusion of IL-1 receptor antagonist (IL-1RA) into the dorsal hippocampus (DH) 30 min before each of the five conditioning sessions (IL-1RA With Cond). Rats in another group received an IL-1RA infusion into the DH 24 h after the previous conditioning session, on non-conditioning days (IL-1RA 24 h After Cond). Number of injections and injection manipulations were balanced between each group using saline infusions. Six days after the last infusion, half of the animals from each group were either re-exposed to the heroin-paired context (CS) to test for conditioned immunosuppression or remained in the home-cage for an equivalent period of time (HC). Immediately following, all animals were given a single injection of LPS and were sacrificed 6 hours later.