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. Author manuscript; available in PMC: 2020 Mar 1.
Published in final edited form as: Psychopharmacology (Berl). 2018 Sep 19;236(3):1057–1066. doi: 10.1007/s00213-018-5029-y

Figure 5. Effects of cumulative mephedrone administration on ICSS before, during, and after repeated daily mephedrone treatment (N=5).

Figure 5.

Panels a-e show full frequency-rate curves on a given test day. The title of each panel shows the test day and the mephedrone treatment administered daily for the six days preceding that test day. Abscissae: frequency of electrical brain stimulation in log Hz. Ordinates: percent maximum control reinforcement rate (% MCR) ± SEM (note that Baseline error is shown in Figure 2 but is not shown here for clarity). Filled symbols show significant differences relative to the baseline on that day as determined by repeated measure two-way analysis of variance (ANOVA) followed by Holm-Sidak post hoc test, p<0.05. Two-way ANOVA results indicated significant main effects of frequency in all panels (p<0.01). Statistical results for the main effect of mephedrone dose and the frequency x dose interaction results were as follows: (a) Day 0: Dose [F(4,16)=43.17, p<0.01], Interaction [F(36,144)=11.49, p<0.01]; (b) Day 7: Dose [F(4,16)=17.95, p<0.01], Interaction [F(36,144)=10.77, p<0.01]; (c) Day 14: Dose [F(4,16)=5.02, p<0.01], Interaction [F(36,144)=8.50, p<0.01]; (d) Day 21: Dose [F(4,16)=1.98, p=0.15], Interaction [F(36,144)=5.94, p<0.01]; (e) Day 28: Dose [F(4,16)=1.18, p=0.35], Interaction [F(36,144)=6.98, p<0.01]. Panel f compares mephedrone effects across test days on the summary measure of ICSS. Abscissa: cumulative mephedrone dose in mg/kg. Ordinate: Percent Total Baseline Stimulations per Component ± SEM. There was not significant main effect of test day [F(4,16)=1.44, p=0.27], but there was a significant main effect of mephdrone dose [F(3,12)=14.64, p<0.01], and the interaction was also significant [F(12,48)=3.92, p<0.01].