Fig. 4. Effects of intrabasalis administration of Ringer's solution (control) or SB334867 on the cortical acetylcholine efflux evoked by the pedunculopontine tegmentum nuclei (PPTg) electrical stimulations. Microinjection of Ringer's solution into the basal forebrain did not significantly alter the evoked acetylcholine effluxes by the second PPTg stimulation (  upper panel ), whereas that of SB334867 significantly attenuated at the first 20 min samples (  lower panel ). ST-1 = first PPTg electrical stimulation; ST-2 = second PPTg electrical stimulation. *  P < 0.05  versus ST-2.