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. Author manuscript; available in PMC: 2020 Jan 1.
Published in final edited form as: Psychopharmacology (Berl). 2018 Jul 12;236(1):479–490. doi: 10.1007/s00213-018-4964-y

Figure 4. Illumination of IL terminals in NAshell during cocaine-seeking tests following the drug-free homecage period and extinction training.

Figure 4.

A. First part of experimental timeline for Experiment 3 in which IL terminals in the NAshell were illuminated during cocaine-seeking tests. B. Number of active and inactive lever presses and cocaine infusions for the last 10 d of cocaine self-administration for all rats included in the final analysis. C. Following the last d of self-administration (baseline craving) and the last d of the drug-free homecage period (incubation of craving), rats underwent 1-h cue-induced drug-seeking tests. Left, Rats pressed the active lever more during the incubation-of-craving test than during the baseline craving test, demonstrating incubation of cocaine craving. Right, Active lever presses from baseline- and incubation-of-craving tests, broken down into 15-min bins. *, p < 0.05 compared to baseline test. D. Schematic diagrams of fiber optic placement (left) and manipulations given during cocaine-seeking and open field tests (right). One min before the session, a 473 nm laser was used and, following the session, a 561 nm laser was used. E. Left, Active lever presses during the cue-induced cocaine seeking test. Laser treatment significantly attenuated cocaine seeking compared to sham treatment. Inset, Active lever presses for individual rats following either sham or laser treatment. *, p < 0.05 compared to sham treatment. F. Active lever presses during the cocaine-primed (5 mg/kg) drug-seeking test. Illumination of IL terminals in the NAshell did not alter cocaine-primed drug seeking. G. Experimental timeline for subsequent behavioral procedures in Experiment 3. H. Illumination of IL terminals in the NAshell during cue-induced reinstatement did not significantly alter cocaine seeking following extinction training. *, p < 0.05 compared to extinction baseline. EXT, extinction. Note the decrease in subjects from 16 to 14 due to 2 deaths. I. Illumination of IL terminals in the NAshell during cocaine-primed reinstatement did not significantly alter cocaine seeking following extinction training. *, p < 0.05 relative to extinction baseline. Note the decrease in subjects from 14 to 13 due to failure to re-extinguish following the cue-induced reinstatement. J. Laser treatment did not significantly alter rats’ distance traveled in the open field test compared to sham treatment. Note the decrease in subjects 13 to 12 due to one rat’s death prior to open field testing.