Figure 3
Microinjection of D 1 R antagonist had no effect on the inhibitory effects of HFS. A: Time course of procedure is presented. Pre1: Pre-HFS (before SCH23390 microinjection). Pre2: Pre-HFS (after SCH23390 microinjection). B: The top trace represents ECoG. The second trace is multiple unit discharges evoked by mechanical stimulation. The third trace represents single unit responses selected by cluster analysis from multi-units of the top trace. The bottom trace represents a pressure curve. Nociceptive responses were depressed by HFS delivered to the VTA at 10min. At 60 min after HFS, nociceptive responses showed recovery to the pre-HFS control level. C, D: Mean changes in the duration (C) and frequency (D) of responses are presented. **p<0.01, Error bars represent S.E. n=8.