Effects of anxiolytics or cannabinoid receptor ligands (cannabinoids: CBs) on nicotine (NC)-induced anxiety-related behavioral alterations. The parameter values at 30 min time point for the single NC treatment group (a) and at 60 min time point for the repeated NC treatment group (b) are shown. Data represent means ± SD (n = 7 for each group). The symbols for differences are the same as the other figures. The abbreviations of the co-administered anxiolytics or CBs as demonstrated below the X-axis are noted in the text.