Fig. 4.
Intra-PFC CBD blocks MK801-induced impairment of set-shifting behavior. Blocking NMDA receptors within PFC using high dose of non-competitive antagonist MK801 (concentrations given in µg/hemisphere) induced impairment that was rescued with co-injection of CBD. a The number of trials to shift and (b) total number of errors performed during set-shifting task was increased in the MK801 treated rats. c–e Errors were categorized into perseverative (c), regressive (d) or never-reinforced (e). Detailed analysis revealed that rats that needed more trials to complete the task showed a specific increase in perseverance suggesting impaired flexibility. Data represent mean ± s.e.m. Group sizes (n): VEH (9, same as in Fig. 2), MK8013 (7), MK8016 (7), MK8016/CBD100 (6), MK8016/CBD500 (7). Respective treatment groups were compared with one-way ANOVA followed with Gabriel post-hoc; or Kruskal–Wallis test followed with Mann–Whitney U tests. *p < 0.05; **p < 0.01 vs. VEH group; $p < 0.05; $$p < 0.01 vs. MK8016