The inhibitory effect of DPN inputs could be abolished at the P5 levelled section of the brain stem or by electrolytic lesion of the ventral periaqueductal grey (vPAG).

• 损毁中脑中央灰质腹侧部(vPAG)或按Sawyer图谱；在P5平面横断脑干；可消除DPN的这种抑制效应.