mg/kg of WY14643 partially blocked and 40 mg/kg of WY14643 completely blocked nicotine-induced excitation of dopamine neurons (Fig. 5A,B: effect of WY14643 on firing rate, F(1,48)=20.36, p<.001; and burst firing, F(1,48)=5.98, p<.05). Intravenous administration of methOEA (5 and 10 mg/kg) also completely prevented excitation of dopamine neurons by nicotine (Fig. 5C,D: effects of two doses of methOEA on firing rate: F(1,48)=5.02, p<.05, and F(1,48)=5.24, p<.05; and burst firing: F(1,52)=6.34, p<.05, and F(1,52)=4.73, p<.05). Pretreatment with the PPAR-α antagonist MK886 completely reversed WY14643's blockade of nicotine-induced increases in firing rate (Fig. 5A) and burst firing (Fig. 5B: MK886+WY14643 vs. WY14643, F(1,60)=16.57, p<.01; F(1,60)=18.24, p<.05, for firing rate and burst firing, respectively).
