OXB-IR fibers were located in the central graysubstance, superior and inferior colliculi.
OXB-IR 纤维位于中央灰色物质，上，下丘脑中。
2
In the mesencephalon, OXB-IR fibers were located in the central graysubstance, superior and inferior colliculi, interpeduncular nucleus and raphe nuclei.
在中脑分布于中脑中央灰质、前丘、后丘、脚间核和中缝核；
3
AIM: To analyze the effect of substance K on pain modulation in the periaqueductal gray (PAG) of rats and indicate the neurotransmitter mechanism in endogenous analgesia system.