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. Author manuscript; available in PMC: 2013 Jan 1.
Published in final edited form as: Neuropharmacology. 2011 Jun 29;62(1):167–176. doi: 10.1016/j.neuropharm.2011.06.014

Figure 4.

Figure 4

NorBNI (20 μg/injection, d7 and d10; ICV) administered in the middle of a 14-day binge pattern cocaine regimen (3×15 mg/kg/d, IP) has no effect onICSS thresholds. (A) Schematic of experimental design. NorBNIor vehicle is administered immediately after the ICSS test and 1 hr prior to initiation of the cocaine binge regimen on binge days 7 and 10. (B) NorBNI has no effect on the expression of cocaine withdrawal-induced increases in ICSS thresholds. Rats were treated with vehicle (ICV) and binge vehicle (n=14), vehicle (ICV) and binge cocaine (n=14), norBNI (ICV) and binge vehicle (n=7), or norBNI (ICV) and binge cocaine (n=15) and ICSS thresholds were measured 21-hr after the end of each daily binge. (C) NorBNI does not significantly affect maximum rates of responding at any time point during the 14-day binge. (D) ICSS thresholds for each treatment are shown at early (day 2), mid (day 8) and late (day 14) stages of the binge pattern cocaine regimen. (E) After cessation of binge cocaine, ICSS thresholds return to vehicle control levels over time. Data are expressed as a percent of pre-binge baseline thresholds (±SEM) during 60-min tests. *P<0.05, **P<0.01 compared to vehicle-treated rats at the same time points; δδP<0.01 comparing norBNI (ICV) and binge cocaine to vehicle (ICV) and binge vehicle-treated rats at the same time points;#P<0.05, ##P<0.01 comparing vehicle (ICV) and binge cocaine to norBNI (ICV) and binge cocaine at the indicated time points. Bonferroni (Dunn's) posthoc tests.