Fig. 5. Recording sites. The depth macroelectrodes (dark circles) were located in the caudal midbrain reticular formation (RF), the rostral midbrain RF–caudal thalamic interface and the rostral thalamus (thal). The microelectrodes (gray squares) were located in the caudal midbrain RF. A few of the macroelectrode sites were estimated from the location of other sites, and one of the microelectrode sites was not recovered. The top , middle , and bottom  sections are at 22 mm, 10 mm, and 3 mm rostral to the interaural line, respectively. PAG = periaqueductal gray.