Fig. 2. Examples of responses of spinal dorsal horn neurons to the incision and suturing during surgery in the control group ( A ), the 1.1% halothane (Hal) group ( B ), the 2.2% halothane (Hal) group ( C ), the 1.4% isoflurane (Iso) group ( D ), and the 2.8% isoflurane (Iso) group. Firing rates and raw spike data are shown in the upper and lower panels, respectively. I, incision; S, suturing.