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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 3.

Figure 3

NorBNI(20 μg, ICV) administered 24 hr prior to the start of binge pattern cocaine (3×15 mg/kg/d, IP)attenuates the development of withdrawal-induced increases inICSS thresholds. (A) Schematic of experimental design. NorBNIor vehicleis administered 24 hr prior to d0. ICSS behavior is recorded 1 hr prior to the first cocaine injection of each day. (B) NorBNI attenuates the development of cocaine withdrawal-induced increases inICSS thresholds. Rats were treated with vehicle (ICV) and binge vehicle (n=14), vehicle (ICV) and binge cocaine (n=18), norBNI (ICV) and binge vehicle (n=8), or norBNI (ICV) and binge cocaine (n=16) 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. NorBNI pretreatment significantly blocks binge cocaine-induced elevations in ICSS thresholds at days 8 and 14. (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 comparing vehicle (ICV) and binge cocaine to vehicle (ICV) and binge 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.